[wifi] Fix ESP8266 DHCP state corruption from premature dhcp_renew()

wifi_apply_hostname_() calls dhcp_renew() on all interfaces with DHCP
data, including when WiFi is not yet connected. lwIP's dhcp_renew()
unconditionally sets the DHCP state to RENEWING (line 1159 in dhcp.c)
before attempting to send, and never rolls back the state on failure.

This corrupts the DHCP state machine: when WiFi later connects and
dhcp_network_changed() is called, it sees RENEWING state and calls
dhcp_reboot() instead of dhcp_discover(). dhcp_reboot() sends a
broadcast DHCP REQUEST for IP 0.0.0.0 (since no lease was ever
obtained), which can put some routers into a persistent bad state
that requires a router restart to clear.

This bug has existed since commit 072b2c445c (Dec 2019, "Add ESP8266
core v2.6.2") and affects every ESP8266 WiFi connection attempt. Most
routers handle the bogus DHCP REQUEST gracefully (NAK then fallback
to DISCOVER), but affected routers get stuck and refuse connections
from the device until restarted.

Fix: guard the dhcp_renew() call with netif_is_link_up() so it only
runs when the interface actually has an active link. The hostname is
still set on the netif regardless, so it will be included in DHCP
packets when the connection is established normally.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CODEOWNERS

@@ -411,6 +411,7 @@ esphome/components/rp2040_pwm/* @jesserockz
 esphome/components/rpi_dpi_rgb/* @clydebarrow
 esphome/components/rtl87xx/* @kuba2k2
 esphome/components/rtttl/* @glmnet
+esphome/components/runtime_image/* @clydebarrow @guillempages @kahrendt
 esphome/components/runtime_stats/* @bdraco
 esphome/components/rx8130/* @beormund
 esphome/components/safe_mode/* @jsuanet @kbx81 @paulmonigatti

esphome/analyze_memory/cli.py

@@ -5,7 +5,6 @@ from __future__ import annotations
 from collections import defaultdict
 from collections.abc import Callable
 import heapq
-import json
 from operator import itemgetter
 import sys
 from typing import TYPE_CHECKING
@@ -541,28 +540,6 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
 
         return "\n".join(lines)
 
-    def to_json(self) -> str:
-        """Export analysis results as JSON."""
-        data = {
-            "components": {
-                name: {
-                    "text": mem.text_size,
-                    "rodata": mem.rodata_size,
-                    "data": mem.data_size,
-                    "bss": mem.bss_size,
-                    "flash_total": mem.flash_total,
-                    "ram_total": mem.ram_total,
-                    "symbol_count": mem.symbol_count,
-                }
-                for name, mem in self.components.items()
-            },
-            "totals": {
-                "flash": sum(c.flash_total for c in self.components.values()),
-                "ram": sum(c.ram_total for c in self.components.values()),
-            },
-        }
-        return json.dumps(data, indent=2)
-
     def dump_uncategorized_symbols(self, output_file: str | None = None) -> None:
         """Dump uncategorized symbols for analysis."""
         # Sort by size descending

esphome/codegen.py

@@ -11,7 +11,6 @@
 from esphome.cpp_generator import (  # noqa: F401
     ArrayInitializer,
     Expression,
-    FlashStringLiteral,
     LineComment,
     LogStringLiteral,
     MockObj,

esphome/components/api/__init__.py

@@ -524,24 +524,24 @@ async def homeassistant_service_to_code(
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, False)
-    templ = await cg.templatable(config[CONF_ACTION], args, cg.std_string)
+    templ = await cg.templatable(config[CONF_ACTION], args, None)
     cg.add(var.set_service(templ))
 
     # Initialize FixedVectors with exact sizes from config
     cg.add(var.init_data(len(config[CONF_DATA])))
     for key, value in config[CONF_DATA].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_data(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_data(key, templ))
 
     cg.add(var.init_data_template(len(config[CONF_DATA_TEMPLATE])))
     for key, value in config[CONF_DATA_TEMPLATE].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_data_template(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_data_template(key, templ))
 
     cg.add(var.init_variables(len(config[CONF_VARIABLES])))
     for key, value in config[CONF_VARIABLES].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_variable(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_variable(key, templ))
 
     if on_error := config.get(CONF_ON_ERROR):
         cg.add_define("USE_API_HOMEASSISTANT_ACTION_RESPONSES")
@@ -609,24 +609,24 @@ async def homeassistant_event_to_code(config, action_id, template_arg, args):
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, True)
-    templ = await cg.templatable(config[CONF_EVENT], args, cg.std_string)
+    templ = await cg.templatable(config[CONF_EVENT], args, None)
     cg.add(var.set_service(templ))
 
     # Initialize FixedVectors with exact sizes from config
     cg.add(var.init_data(len(config[CONF_DATA])))
     for key, value in config[CONF_DATA].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_data(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_data(key, templ))
 
     cg.add(var.init_data_template(len(config[CONF_DATA_TEMPLATE])))
     for key, value in config[CONF_DATA_TEMPLATE].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_data_template(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_data_template(key, templ))
 
     cg.add(var.init_variables(len(config[CONF_VARIABLES])))
     for key, value in config[CONF_VARIABLES].items():
-        templ = await cg.templatable(value, args, cg.std_string)
-        cg.add(var.add_variable(cg.FlashStringLiteral(key), templ))
+        templ = await cg.templatable(value, args, None)
+        cg.add(var.add_variable(key, templ))
 
     return var
 
@@ -649,11 +649,11 @@ async def homeassistant_tag_scanned_to_code(config, action_id, template_arg, arg
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, True)
-    cg.add(var.set_service(cg.FlashStringLiteral("esphome.tag_scanned")))
+    cg.add(var.set_service("esphome.tag_scanned"))
     # Initialize FixedVector with exact size (1 data field)
     cg.add(var.init_data(1))
     templ = await cg.templatable(config[CONF_TAG], args, cg.std_string)
-    cg.add(var.add_data(cg.FlashStringLiteral("tag_id"), templ))
+    cg.add(var.add_data("tag_id", templ))
     return var
 
 

esphome/components/api/homeassistant_service.h

@@ -128,20 +128,6 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
     this->add_kv_(this->variables_, key, std::forward<V>(value));
   }
 
-#ifdef USE_ESP8266
-  // On ESP8266, ESPHOME_F() returns __FlashStringHelper* (PROGMEM pointer).
-  // Store as const char* — populate_service_map copies from PROGMEM at play() time.
-  template<typename V> void add_data(const __FlashStringHelper *key, V &&value) {
-    this->add_kv_(this->data_, reinterpret_cast<const char *>(key), std::forward<V>(value));
-  }
-  template<typename V> void add_data_template(const __FlashStringHelper *key, V &&value) {
-    this->add_kv_(this->data_template_, reinterpret_cast<const char *>(key), std::forward<V>(value));
-  }
-  template<typename V> void add_variable(const __FlashStringHelper *key, V &&value) {
-    this->add_kv_(this->variables_, reinterpret_cast<const char *>(key), std::forward<V>(value));
-  }
-#endif
-
 #ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   template<typename T> void set_response_template(T response_template) {
     this->response_template_ = response_template;
@@ -233,31 +219,7 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
                                    Ts... x) {
     dest.init(source.size());
 
-#ifdef USE_ESP8266
-    // On ESP8266, keys may be in PROGMEM (from ESPHOME_F in codegen) and
-    // FLASH_STRING values need copying via _P functions.
-    // Allocate storage for all keys + all values (2 entries per source item).
-    // strlen_P/memcpy_P handle both RAM and PROGMEM pointers safely.
-    value_storage.init(source.size() * 2);
-
-    for (auto &it : source) {
-      auto &kv = dest.emplace_back();
-
-      // Key: copy from possible PROGMEM
-      {
-        size_t key_len = strlen_P(it.key);
-        value_storage.push_back(std::string(key_len, '\0'));
-        memcpy_P(value_storage.back().data(), it.key, key_len);
-        kv.key = StringRef(value_storage.back());
-      }
-
-      // Value: value() handles FLASH_STRING via _P functions internally
-      value_storage.push_back(it.value.value(x...));
-      kv.value = StringRef(value_storage.back());
-    }
-#else
-    // On non-ESP8266, strings are directly readable from flash-mapped memory.
-    // Count non-static strings to allocate exact storage needed.
+    // Count non-static strings to allocate exact storage needed
     size_t lambda_count = 0;
     for (const auto &it : source) {
       if (!it.value.is_static_string()) {
@@ -271,15 +233,14 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
       kv.key = StringRef(it.key);
 
       if (it.value.is_static_string()) {
-        // Static string — pointer directly readable, zero allocation
+        // Static string from YAML - zero allocation
         kv.value = StringRef(it.value.get_static_string());
       } else {
-        // Lambda — evaluate and store result
+        // Lambda evaluation - store result, reference it
         value_storage.push_back(it.value.value(x...));
         kv.value = StringRef(value_storage.back());
       }
     }
-#endif
   }
 
   APIServer *parent_;

esphome/components/api/user_services.h

@@ -264,9 +264,9 @@ template<typename... Ts> class APIRespondAction : public Action<Ts...> {
       // Build and send JSON response
       json::JsonBuilder builder;
       this->json_builder_(x..., builder.root());
-      auto json_buf = builder.serialize();
+      std::string json_str = builder.serialize();
       this->parent_->send_action_response(call_id, success, StringRef(error_message),
-                                          reinterpret_cast<const uint8_t *>(json_buf.data()), json_buf.size());
+                                          reinterpret_cast<const uint8_t *>(json_str.data()), json_str.size());
       return;
     }
 #endif

esphome/components/bedjet/bedjet_hub.cpp

@@ -3,7 +3,6 @@
 #include "bedjet_hub.h"
 #include "bedjet_child.h"
 #include "bedjet_const.h"
-#include "esphome/components/esp32_ble/ble_uuid.h"
 #include "esphome/core/application.h"
 #include <cinttypes>
 

esphome/components/display/__init__.py

@@ -63,13 +63,11 @@ def validate_auto_clear(value):
     return cv.boolean(value)
 
 
-def basic_display_schema(default_update_interval: str = "1s") -> cv.Schema:
-    """Create a basic display schema with configurable default update interval."""
-    return cv.Schema(
-        {
-            cv.Exclusive(CONF_LAMBDA, CONF_LAMBDA): cv.lambda_,
-        }
-    ).extend(cv.polling_component_schema(default_update_interval))
+BASIC_DISPLAY_SCHEMA = cv.Schema(
+    {
+        cv.Exclusive(CONF_LAMBDA, CONF_LAMBDA): cv.lambda_,
+    }
+).extend(cv.polling_component_schema("1s"))
 
 
 def _validate_test_card(config):
@@ -83,41 +81,34 @@ def _validate_test_card(config):
     return config
 
 
-def full_display_schema(default_update_interval: str = "1s") -> cv.Schema:
-    """Create a full display schema with configurable default update interval."""
-    schema = basic_display_schema(default_update_interval).extend(
-        {
-            cv.Optional(CONF_ROTATION): validate_rotation,
-            cv.Exclusive(CONF_PAGES, CONF_LAMBDA): cv.All(
-                cv.ensure_list(
-                    {
-                        cv.GenerateID(): cv.declare_id(DisplayPage),
-                        cv.Required(CONF_LAMBDA): cv.lambda_,
-                    }
-                ),
-                cv.Length(min=1),
-            ),
-            cv.Optional(CONF_ON_PAGE_CHANGE): automation.validate_automation(
+FULL_DISPLAY_SCHEMA = BASIC_DISPLAY_SCHEMA.extend(
+    {
+        cv.Optional(CONF_ROTATION): validate_rotation,
+        cv.Exclusive(CONF_PAGES, CONF_LAMBDA): cv.All(
+            cv.ensure_list(
                 {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(
-                        DisplayOnPageChangeTrigger
-                    ),
-                    cv.Optional(CONF_FROM): cv.use_id(DisplayPage),
-                    cv.Optional(CONF_TO): cv.use_id(DisplayPage),
+                    cv.GenerateID(): cv.declare_id(DisplayPage),
+                    cv.Required(CONF_LAMBDA): cv.lambda_,
                 }
             ),
-            cv.Optional(
-                CONF_AUTO_CLEAR_ENABLED, default=CONF_UNSPECIFIED
-            ): validate_auto_clear,
-            cv.Optional(CONF_SHOW_TEST_CARD): cv.boolean,
-        }
-    )
-    schema.add_extra(_validate_test_card)
-    return schema
-
-
-BASIC_DISPLAY_SCHEMA = basic_display_schema("1s")
-FULL_DISPLAY_SCHEMA = full_display_schema("1s")
+            cv.Length(min=1),
+        ),
+        cv.Optional(CONF_ON_PAGE_CHANGE): automation.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(
+                    DisplayOnPageChangeTrigger
+                ),
+                cv.Optional(CONF_FROM): cv.use_id(DisplayPage),
+                cv.Optional(CONF_TO): cv.use_id(DisplayPage),
+            }
+        ),
+        cv.Optional(
+            CONF_AUTO_CLEAR_ENABLED, default=CONF_UNSPECIFIED
+        ): validate_auto_clear,
+        cv.Optional(CONF_SHOW_TEST_CARD): cv.boolean,
+    }
+)
+FULL_DISPLAY_SCHEMA.add_extra(_validate_test_card)
 
 
 async def setup_display_core_(var, config):

esphome/components/esp32/gpio.cpp

@@ -85,6 +85,7 @@ void ESP32InternalGPIOPin::attach_interrupt(void (*func)(void *), void *arg, gpi
       break;
   }
   gpio_set_intr_type(this->get_pin_num(), idf_type);
+  gpio_intr_enable(this->get_pin_num());
   if (!isr_service_installed) {
     auto res = gpio_install_isr_service(ESP_INTR_FLAG_LEVEL3);
     if (res != ESP_OK) {
@@ -94,7 +95,6 @@ void ESP32InternalGPIOPin::attach_interrupt(void (*func)(void *), void *arg, gpi
     isr_service_installed = true;
   }
   gpio_isr_handler_add(this->get_pin_num(), func, arg);
-  gpio_intr_enable(this->get_pin_num());
 }
 
 size_t ESP32InternalGPIOPin::dump_summary(char *buffer, size_t len) const {

esphome/components/esp32/preferences.cpp

@@ -19,7 +19,16 @@ static constexpr size_t KEY_BUFFER_SIZE = 12;
 
 struct NVSData {
   uint32_t key;
-  SmallInlineBuffer<8> data;  // Most prefs fit in 8 bytes (covers fan, cover, select, etc.)
+  std::unique_ptr<uint8_t[]> data;
+  size_t len;
+
+  void set_data(const uint8_t *src, size_t size) {
+    if (!this->data || this->len != size) {
+      this->data = std::make_unique<uint8_t[]>(size);
+      this->len = size;
+    }
+    memcpy(this->data.get(), src, size);
+  }
 };
 
 static std::vector<NVSData> s_pending_save;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
@@ -32,14 +41,14 @@ class ESP32PreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and update that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        obj.data.set(data, len);
+        obj.set_data(data, len);
         return true;
       }
     }
     NVSData save{};
     save.key = this->key;
-    save.data.set(data, len);
-    s_pending_save.push_back(std::move(save));
+    save.set_data(data, len);
+    s_pending_save.emplace_back(std::move(save));
     ESP_LOGVV(TAG, "s_pending_save: key: %" PRIu32 ", len: %zu", this->key, len);
     return true;
   }
@@ -47,11 +56,11 @@ class ESP32PreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and load from that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        if (obj.data.size() != len) {
+        if (obj.len != len) {
           // size mismatch
           return false;
         }
-        memcpy(data, obj.data.data(), len);
+        memcpy(data, obj.data.get(), len);
         return true;
       }
     }
@@ -124,10 +133,10 @@ class ESP32Preferences : public ESPPreferences {
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if NVS data %s has changed", key_str);
       if (this->is_changed_(this->nvs_handle, save, key_str)) {
-        esp_err_t err = nvs_set_blob(this->nvs_handle, key_str, save.data.data(), save.data.size());
-        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.data.size());
+        esp_err_t err = nvs_set_blob(this->nvs_handle, key_str, save.data.get(), save.len);
+        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.len);
         if (err != 0) {
-          ESP_LOGV(TAG, "nvs_set_blob('%s', len=%zu) failed: %s", key_str, save.data.size(), esp_err_to_name(err));
+          ESP_LOGV(TAG, "nvs_set_blob('%s', len=%zu) failed: %s", key_str, save.len, esp_err_to_name(err));
           failed++;
           last_err = err;
           last_key = save.key;
@@ -135,7 +144,7 @@ class ESP32Preferences : public ESPPreferences {
         }
         written++;
       } else {
-        ESP_LOGV(TAG, "NVS data not changed skipping %" PRIu32 "  len=%zu", save.key, save.data.size());
+        ESP_LOGV(TAG, "NVS data not changed skipping %" PRIu32 "  len=%zu", save.key, save.len);
         cached++;
       }
     }
@@ -167,7 +176,7 @@ class ESP32Preferences : public ESPPreferences {
       return true;
     }
     // Check size first before allocating memory
-    if (actual_len != to_save.data.size()) {
+    if (actual_len != to_save.len) {
       return true;
     }
     // Most preferences are small, use stack buffer with heap fallback for large ones
@@ -177,7 +186,7 @@ class ESP32Preferences : public ESPPreferences {
       ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", key_str, esp_err_to_name(err));
       return true;
     }
-    return memcmp(to_save.data.data(), stored_data.get(), to_save.data.size()) != 0;
+    return memcmp(to_save.data.get(), stored_data.get(), to_save.len) != 0;
   }
 
   bool reset() override {

esphome/components/esp32_ble/ble.cpp

@@ -98,10 +98,6 @@ void ESP32BLE::advertising_set_service_data(const std::vector<uint8_t> &data) {
 }
 
 void ESP32BLE::advertising_set_manufacturer_data(const std::vector<uint8_t> &data) {
-  this->advertising_set_manufacturer_data(std::span<const uint8_t>(data));
-}
-
-void ESP32BLE::advertising_set_manufacturer_data(std::span<const uint8_t> data) {
   this->advertising_init_();
   this->advertising_->set_manufacturer_data(data);
   this->advertising_start();

esphome/components/esp32_ble/ble.h

@@ -118,7 +118,6 @@ class ESP32BLE : public Component {
   void advertising_start();
   void advertising_set_service_data(const std::vector<uint8_t> &data);
   void advertising_set_manufacturer_data(const std::vector<uint8_t> &data);
-  void advertising_set_manufacturer_data(std::span<const uint8_t> data);
   void advertising_set_appearance(uint16_t appearance) { this->appearance_ = appearance; }
   void advertising_set_service_data_and_name(std::span<const uint8_t> data, bool include_name);
   void advertising_add_service_uuid(ESPBTUUID uuid);

esphome/components/esp32_ble/ble_advertising.cpp

@@ -59,10 +59,6 @@ void BLEAdvertising::set_service_data(const std::vector<uint8_t> &data) {
 }
 
 void BLEAdvertising::set_manufacturer_data(const std::vector<uint8_t> &data) {
-  this->set_manufacturer_data(std::span<const uint8_t>(data));
-}
-
-void BLEAdvertising::set_manufacturer_data(std::span<const uint8_t> data) {
   delete[] this->advertising_data_.p_manufacturer_data;
   this->advertising_data_.p_manufacturer_data = nullptr;
   this->advertising_data_.manufacturer_len = data.size();

esphome/components/esp32_ble/ble_advertising.h

@@ -28,7 +28,6 @@ class BLEAdvertising {
   void set_scan_response(bool scan_response) { this->scan_response_ = scan_response; }
   void set_min_preferred_interval(uint16_t interval) { this->advertising_data_.min_interval = interval; }
   void set_manufacturer_data(const std::vector<uint8_t> &data);
-  void set_manufacturer_data(std::span<const uint8_t> data);
   void set_appearance(uint16_t appearance) { this->advertising_data_.appearance = appearance; }
   void set_service_data(const std::vector<uint8_t> &data);
   void set_service_data(std::span<const uint8_t> data);

esphome/components/esp32_ble_beacon/esp32_ble_beacon.cpp

@@ -1,6 +1,5 @@
 #include "esp32_ble_beacon.h"
 #include "esphome/core/log.h"
-#include "esphome/core/helpers.h"
 
 #ifdef USE_ESP32
 

esphome/components/esp32_ble_server/ble_server_automations.cpp

@@ -15,10 +15,7 @@ Trigger<std::vector<uint8_t>, uint16_t> *BLETriggers::create_characteristic_on_w
   Trigger<std::vector<uint8_t>, uint16_t> *on_write_trigger =  // NOLINT(cppcoreguidelines-owning-memory)
       new Trigger<std::vector<uint8_t>, uint16_t>();
   characteristic->on_write([on_write_trigger](std::span<const uint8_t> data, uint16_t id) {
-    // Convert span to vector for trigger - copy is necessary because:
-    // 1. Trigger stores the data for use in automation actions that execute later
-    // 2. The span is only valid during this callback (points to temporary BLE stack data)
-    // 3. User lambdas in automations need persistent data they can access asynchronously
+    // Convert span to vector for trigger
     on_write_trigger->trigger(std::vector<uint8_t>(data.begin(), data.end()), id);
   });
   return on_write_trigger;
@@ -30,10 +27,7 @@ Trigger<std::vector<uint8_t>, uint16_t> *BLETriggers::create_descriptor_on_write
   Trigger<std::vector<uint8_t>, uint16_t> *on_write_trigger =  // NOLINT(cppcoreguidelines-owning-memory)
       new Trigger<std::vector<uint8_t>, uint16_t>();
   descriptor->on_write([on_write_trigger](std::span<const uint8_t> data, uint16_t id) {
-    // Convert span to vector for trigger - copy is necessary because:
-    // 1. Trigger stores the data for use in automation actions that execute later
-    // 2. The span is only valid during this callback (points to temporary BLE stack data)
-    // 3. User lambdas in automations need persistent data they can access asynchronously
+    // Convert span to vector for trigger
     on_write_trigger->trigger(std::vector<uint8_t>(data.begin(), data.end()), id);
   });
   return on_write_trigger;

esphome/components/fan/fan.cpp

@@ -68,7 +68,7 @@ void FanCall::validate_() {
   auto traits = this->parent_.get_traits();
 
   if (this->speed_.has_value()) {
-    this->speed_ = clamp(*this->speed_, 1, static_cast<int>(traits.supported_speed_count()));
+    this->speed_ = clamp(*this->speed_, 1, traits.supported_speed_count());
 
     // https://developers.home-assistant.io/docs/core/entity/fan/#preset-modes
     // "Manually setting a speed must disable any set preset mode"

esphome/components/fan/fan_traits.h

@@ -11,7 +11,7 @@ namespace fan {
 class FanTraits {
  public:
   FanTraits() = default;
-  FanTraits(bool oscillation, bool speed, bool direction, uint8_t speed_count)
+  FanTraits(bool oscillation, bool speed, bool direction, int speed_count)
       : oscillation_(oscillation), speed_(speed), direction_(direction), speed_count_(speed_count) {}
 
   /// Return if this fan supports oscillation.
@@ -23,9 +23,9 @@ class FanTraits {
   /// Set whether this fan supports speed levels.
   void set_speed(bool speed) { this->speed_ = speed; }
   /// Return how many speed levels the fan has
-  uint8_t supported_speed_count() const { return this->speed_count_; }
+  int supported_speed_count() const { return this->speed_count_; }
   /// Set how many speed levels this fan has.
-  void set_supported_speed_count(uint8_t speed_count) { this->speed_count_ = speed_count; }
+  void set_supported_speed_count(int speed_count) { this->speed_count_ = speed_count; }
   /// Return if this fan supports changing direction
   bool supports_direction() const { return this->direction_; }
   /// Set whether this fan supports changing direction
@@ -64,7 +64,7 @@ class FanTraits {
   bool oscillation_{false};
   bool speed_{false};
   bool direction_{false};
-  uint8_t speed_count_{};
+  int speed_count_{};
   std::vector<const char *> preset_modes_{};
 };
 

esphome/components/hbridge/fan/__init__.py

@@ -39,7 +39,7 @@ CONFIG_SCHEMA = (
             cv.Optional(CONF_DECAY_MODE, default="SLOW"): cv.enum(
                 DECAY_MODE_OPTIONS, upper=True
             ),
-            cv.Optional(CONF_SPEED_COUNT, default=100): cv.int_range(min=1, max=255),
+            cv.Optional(CONF_SPEED_COUNT, default=100): cv.int_range(min=1),
             cv.Optional(CONF_ENABLE_PIN): cv.use_id(output.FloatOutput),
             cv.Optional(CONF_PRESET_MODES): validate_preset_modes,
         }

esphome/components/hbridge/fan/hbridge_fan.h

@@ -15,7 +15,7 @@ enum DecayMode {
 
 class HBridgeFan : public Component, public fan::Fan {
  public:
-  HBridgeFan(uint8_t speed_count, DecayMode decay_mode) : speed_count_(speed_count), decay_mode_(decay_mode) {}
+  HBridgeFan(int speed_count, DecayMode decay_mode) : speed_count_(speed_count), decay_mode_(decay_mode) {}
 
   void set_pin_a(output::FloatOutput *pin_a) { pin_a_ = pin_a; }
   void set_pin_b(output::FloatOutput *pin_b) { pin_b_ = pin_b; }
@@ -33,7 +33,7 @@ class HBridgeFan : public Component, public fan::Fan {
   output::FloatOutput *pin_b_;
   output::FloatOutput *enable_{nullptr};
   output::BinaryOutput *oscillating_{nullptr};
-  uint8_t speed_count_{};
+  int speed_count_{};
   DecayMode decay_mode_{DECAY_MODE_SLOW};
   fan::FanTraits traits_;
   std::vector<const char *> preset_modes_{};

esphome/components/i2c/i2c_bus_esp_idf.cpp

@@ -119,7 +119,7 @@ void IDFI2CBus::dump_config() {
         if (s.second) {
           ESP_LOGCONFIG(TAG, "Found device at address 0x%02X", s.first);
         } else {
-          ESP_LOGCONFIG(TAG, "Unknown error at address 0x%02X", s.first);
+          ESP_LOGE(TAG, "Unknown error at address 0x%02X", s.first);
         }
       }
     }

esphome/components/json/json_util.cpp

@@ -15,7 +15,7 @@ static const char *const TAG = "json";
 static SpiRamAllocator global_json_allocator;
 #endif
 
-SerializationBuffer<> build_json(const json_build_t &f) {
+std::string build_json(const json_build_t &f) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   JsonBuilder builder;
   JsonObject root = builder.root();
@@ -66,62 +66,14 @@ JsonDocument parse_json(const uint8_t *data, size_t len) {
   // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 }
 
-SerializationBuffer<> JsonBuilder::serialize() {
-  // ===========================================================================================
-  // CRITICAL: NRVO (Named Return Value Optimization) - DO NOT REFACTOR WITHOUT UNDERSTANDING
-  // ===========================================================================================
-  //
-  // This function is carefully structured to enable NRVO. The compiler constructs `result`
-  // directly in the caller's stack frame, eliminating the move constructor call entirely.
-  //
-  // WITHOUT NRVO: Each return would trigger SerializationBuffer's move constructor, which
-  // must memcpy up to 512 bytes of stack buffer content. This happens on EVERY JSON
-  // serialization (sensor updates, web server responses, MQTT publishes, etc.).
-  //
-  // WITH NRVO: Zero memcpy, zero move constructor overhead. The buffer lives directly
-  // where the caller needs it.
-  //
-  // Requirements for NRVO to work:
-  //   1. Single named variable (`result`) returned from ALL paths
-  //   2. All paths must return the SAME variable (not different variables)
-  //   3. No std::move() on the return statement
-  //
-  // If you must modify this function:
-  //   - Keep a single `result` variable declared at the top
-  //   - All code paths must return `result` (not a different variable)
-  //   - Verify NRVO still works by checking the disassembly for move constructor calls
-  //   - Test: objdump -d -C firmware.elf | grep "SerializationBuffer.*SerializationBuffer"
-  //     Should show only destructor, NOT move constructor
-  //
-  // Why we avoid measureJson(): It instantiates DummyWriter templates adding ~1KB flash.
-  // Instead, try stack buffer first. 512 bytes covers 99.9% of JSON payloads (sensors ~200B,
-  // lights ~170B, climate ~700B). Only entities with 40+ options exceed this.
-  //
-  // ===========================================================================================
-  constexpr size_t buf_size = SerializationBuffer<>::BUFFER_SIZE;
-  SerializationBuffer<> result(buf_size - 1);  // Max content size (reserve 1 for null)
-
+std::string JsonBuilder::serialize() {
   if (doc_.overflowed()) {
     ESP_LOGE(TAG, "JSON document overflow");
-    auto *buf = result.data_writable_();
-    buf[0] = '{';
-    buf[1] = '}';
-    buf[2] = '\0';
-    result.set_size_(2);
-    return result;
+    return "{}";
   }
-
-  size_t size = serializeJson(doc_, result.data_writable_(), buf_size);
-  if (size < buf_size) {
-    // Fits in stack buffer - update size to actual length
-    result.set_size_(size);
-    return result;
-  }
-
-  // Needs heap allocation - reallocate and serialize again with exact size
-  result.reallocate_heap_(size);
-  serializeJson(doc_, result.data_writable_(), size + 1);
-  return result;
+  std::string output;
+  serializeJson(doc_, output);
+  return output;
 }
 
 }  // namespace json

esphome/components/json/json_util.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <cstring>
-#include <string>
 #include <vector>
 
 #include "esphome/core/defines.h"
@@ -16,108 +14,6 @@
 namespace esphome {
 namespace json {
 
-/// Buffer for JSON serialization that uses stack allocation for small payloads.
-/// Template parameter STACK_SIZE specifies the stack buffer size (default 512 bytes).
-/// Supports move semantics for efficient return-by-value.
-template<size_t STACK_SIZE = 512> class SerializationBuffer {
- public:
-  static constexpr size_t BUFFER_SIZE = STACK_SIZE;  ///< Stack buffer size for this instantiation
-
-  /// Construct with known size (typically from measureJson)
-  explicit SerializationBuffer(size_t size) : size_(size) {
-    if (size + 1 <= STACK_SIZE) {
-      buffer_ = stack_buffer_;
-    } else {
-      heap_buffer_ = new char[size + 1];
-      buffer_ = heap_buffer_;
-    }
-    buffer_[0] = '\0';
-  }
-
-  ~SerializationBuffer() { delete[] heap_buffer_; }
-
-  // Move constructor - works with same template instantiation
-  SerializationBuffer(SerializationBuffer &&other) noexcept : heap_buffer_(other.heap_buffer_), size_(other.size_) {
-    if (other.buffer_ == other.stack_buffer_) {
-      // Stack buffer - must copy content
-      std::memcpy(stack_buffer_, other.stack_buffer_, size_ + 1);
-      buffer_ = stack_buffer_;
-    } else {
-      // Heap buffer - steal ownership
-      buffer_ = heap_buffer_;
-      other.heap_buffer_ = nullptr;
-    }
-    // Leave moved-from object in valid empty state
-    other.stack_buffer_[0] = '\0';
-    other.buffer_ = other.stack_buffer_;
-    other.size_ = 0;
-  }
-
-  // Move assignment
-  SerializationBuffer &operator=(SerializationBuffer &&other) noexcept {
-    if (this != &other) {
-      delete[] heap_buffer_;
-      heap_buffer_ = other.heap_buffer_;
-      size_ = other.size_;
-      if (other.buffer_ == other.stack_buffer_) {
-        std::memcpy(stack_buffer_, other.stack_buffer_, size_ + 1);
-        buffer_ = stack_buffer_;
-      } else {
-        buffer_ = heap_buffer_;
-        other.heap_buffer_ = nullptr;
-      }
-      // Leave moved-from object in valid empty state
-      other.stack_buffer_[0] = '\0';
-      other.buffer_ = other.stack_buffer_;
-      other.size_ = 0;
-    }
-    return *this;
-  }
-
-  // Delete copy operations
-  SerializationBuffer(const SerializationBuffer &) = delete;
-  SerializationBuffer &operator=(const SerializationBuffer &) = delete;
-
-  /// Get null-terminated C string
-  const char *c_str() const { return buffer_; }
-  /// Get data pointer
-  const char *data() const { return buffer_; }
-  /// Get string length (excluding null terminator)
-  size_t size() const { return size_; }
-
-  /// Implicit conversion to std::string for backward compatibility
-  /// WARNING: This allocates a new std::string on the heap. Prefer using
-  /// c_str() or data()/size() directly when possible to avoid allocation.
-  operator std::string() const { return std::string(buffer_, size_); }  // NOLINT(google-explicit-constructor)
-
- private:
-  friend class JsonBuilder;  ///< Allows JsonBuilder::serialize() to call private methods
-
-  /// Get writable buffer (for serialization)
-  char *data_writable_() { return buffer_; }
-  /// Set actual size after serialization (must not exceed allocated size)
-  /// Also ensures null termination for c_str() safety
-  void set_size_(size_t size) {
-    size_ = size;
-    buffer_[size] = '\0';
-  }
-
-  /// Reallocate to heap buffer with new size (for when stack buffer is too small)
-  /// This invalidates any previous buffer content. Used by JsonBuilder::serialize().
-  void reallocate_heap_(size_t size) {
-    delete[] heap_buffer_;
-    heap_buffer_ = new char[size + 1];
-    buffer_ = heap_buffer_;
-    size_ = size;
-    buffer_[0] = '\0';
-  }
-
-  char stack_buffer_[STACK_SIZE];
-  char *heap_buffer_{nullptr};
-  char *buffer_;
-  size_t size_;
-};
-
 #ifdef USE_PSRAM
 // Build an allocator for the JSON Library using the RAMAllocator class
 // This is only compiled when PSRAM is enabled
@@ -150,8 +46,7 @@ using json_parse_t = std::function<bool(JsonObject)>;
 using json_build_t = std::function<void(JsonObject)>;
 
 /// Build a JSON string with the provided json build function.
-/// Returns SerializationBuffer for stack-first allocation; implicitly converts to std::string.
-SerializationBuffer<> build_json(const json_build_t &f);
+std::string build_json(const json_build_t &f);
 
 /// Parse a JSON string and run the provided json parse function if it's valid.
 bool parse_json(const std::string &data, const json_parse_t &f);
@@ -176,9 +71,7 @@ class JsonBuilder {
     return root_;
   }
 
-  /// Serialize the JSON document to a SerializationBuffer (stack-first allocation)
-  /// Uses 512-byte stack buffer by default, falls back to heap for larger JSON
-  SerializationBuffer<> serialize();
+  std::string serialize();
 
  private:
 #ifdef USE_PSRAM

esphome/components/kuntze/kuntze.cpp

@@ -11,7 +11,7 @@ static const char *const TAG = "kuntze";
 static const uint8_t CMD_READ_REG = 0x03;
 static const uint16_t REGISTER[] = {4136, 4160, 4680, 6000, 4688, 4728, 5832};
 
-// Maximum bytes to log for Modbus responses (2 registers = 4 bytes, plus byte count = 5 bytes)
+// Maximum bytes to log for Modbus responses (2 registers = 4, plus count = 5)
 static constexpr size_t KUNTZE_MAX_LOG_BYTES = 8;
 
 void Kuntze::on_modbus_data(const std::vector<uint8_t> &data) {

esphome/components/libretiny/preferences.cpp

@@ -18,7 +18,16 @@ static constexpr size_t KEY_BUFFER_SIZE = 12;
 
 struct NVSData {
   uint32_t key;
-  SmallInlineBuffer<8> data;  // Most prefs fit in 8 bytes (covers fan, cover, select, etc.)
+  std::unique_ptr<uint8_t[]> data;
+  size_t len;
+
+  void set_data(const uint8_t *src, size_t size) {
+    if (!this->data || this->len != size) {
+      this->data = std::make_unique<uint8_t[]>(size);
+      this->len = size;
+    }
+    memcpy(this->data.get(), src, size);
+  }
 };
 
 static std::vector<NVSData> s_pending_save;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
@@ -33,14 +42,14 @@ class LibreTinyPreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and update that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        obj.data.set(data, len);
+        obj.set_data(data, len);
         return true;
       }
     }
     NVSData save{};
     save.key = this->key;
-    save.data.set(data, len);
-    s_pending_save.push_back(std::move(save));
+    save.set_data(data, len);
+    s_pending_save.emplace_back(std::move(save));
     ESP_LOGVV(TAG, "s_pending_save: key: %" PRIu32 ", len: %zu", this->key, len);
     return true;
   }
@@ -49,11 +58,11 @@ class LibreTinyPreferenceBackend : public ESPPreferenceBackend {
     // try find in pending saves and load from that
     for (auto &obj : s_pending_save) {
       if (obj.key == this->key) {
-        if (obj.data.size() != len) {
+        if (obj.len != len) {
           // size mismatch
           return false;
         }
-        memcpy(data, obj.data.data(), len);
+        memcpy(data, obj.data.get(), len);
         return true;
       }
     }
@@ -114,11 +123,11 @@ class LibreTinyPreferences : public ESPPreferences {
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if FDB data %s has changed", key_str);
       if (this->is_changed_(&this->db, save, key_str)) {
-        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.data.size());
-        fdb_blob_make(&this->blob, save.data.data(), save.data.size());
+        ESP_LOGV(TAG, "sync: key: %s, len: %zu", key_str, save.len);
+        fdb_blob_make(&this->blob, save.data.get(), save.len);
         fdb_err_t err = fdb_kv_set_blob(&this->db, key_str, &this->blob);
         if (err != FDB_NO_ERR) {
-          ESP_LOGV(TAG, "fdb_kv_set_blob('%s', len=%zu) failed: %d", key_str, save.data.size(), err);
+          ESP_LOGV(TAG, "fdb_kv_set_blob('%s', len=%zu) failed: %d", key_str, save.len, err);
           failed++;
           last_err = err;
           last_key = save.key;
@@ -126,7 +135,7 @@ class LibreTinyPreferences : public ESPPreferences {
         }
         written++;
       } else {
-        ESP_LOGD(TAG, "FDB data not changed; skipping %" PRIu32 "  len=%zu", save.key, save.data.size());
+        ESP_LOGD(TAG, "FDB data not changed; skipping %" PRIu32 "  len=%zu", save.key, save.len);
         cached++;
       }
     }
@@ -151,7 +160,7 @@ class LibreTinyPreferences : public ESPPreferences {
     }
 
     // Check size first - if different, data has changed
-    if (kv.value_len != to_save.data.size()) {
+    if (kv.value_len != to_save.len) {
       return true;
     }
 
@@ -165,7 +174,7 @@ class LibreTinyPreferences : public ESPPreferences {
     }
 
     // Compare the actual data
-    return memcmp(to_save.data.data(), stored_data.get(), kv.value_len) != 0;
+    return memcmp(to_save.data.get(), stored_data.get(), kv.value_len) != 0;
   }
 
   bool reset() override {

esphome/components/logger/logger_esp8266.cpp.bak

@@ -1,51 +0,0 @@
-#ifdef USE_ESP8266
-#include "logger.h"
-#include "esphome/core/log.h"
-
-namespace esphome::logger {
-
-static const char *const TAG = "logger";
-
-void Logger::pre_setup() {
-  if (this->baud_rate_ > 0) {
-    switch (this->uart_) {
-      case UART_SELECTION_UART0:
-      case UART_SELECTION_UART0_SWAP:
-        this->hw_serial_ = &Serial;
-        Serial.begin(this->baud_rate_);
-        if (this->uart_ == UART_SELECTION_UART0_SWAP) {
-          Serial.swap();
-        }
-        Serial.setDebugOutput(ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE);
-        break;
-      case UART_SELECTION_UART1:
-        this->hw_serial_ = &Serial1;
-        Serial1.begin(this->baud_rate_);
-        Serial1.setDebugOutput(ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE);
-        break;
-    }
-  } else {
-    uart_set_debug(UART_NO);
-  }
-
-  global_logger = this;
-
-  ESP_LOGI(TAG, "Log initialized");
-}
-
-void HOT Logger::write_msg_(const char *msg) { this->hw_serial_->println(msg); }
-
-const LogString *Logger::get_uart_selection_() {
-  switch (this->uart_) {
-    case UART_SELECTION_UART0:
-      return LOG_STR("UART0");
-    case UART_SELECTION_UART1:
-      return LOG_STR("UART1");
-    case UART_SELECTION_UART0_SWAP:
-    default:
-      return LOG_STR("UART0_SWAP");
-  }
-}
-
-}  // namespace esphome::logger
-#endif

esphome/components/logger/logger_host.cpp.bak

@@ -1,22 +0,0 @@
-#if defined(USE_HOST)
-#include "logger.h"
-
-namespace esphome::logger {
-
-void HOT Logger::write_msg_(const char *msg) {
-  time_t rawtime;
-  struct tm *timeinfo;
-  char buffer[80];
-
-  time(&rawtime);
-  timeinfo = localtime(&rawtime);
-  strftime(buffer, sizeof buffer, "[%H:%M:%S]", timeinfo);
-  fputs(buffer, stdout);
-  puts(msg);
-}
-
-void Logger::pre_setup() { global_logger = this; }
-
-}  // namespace esphome::logger
-
-#endif

esphome/components/logger/logger_libretiny.cpp.bak

@@ -1,70 +0,0 @@
-#ifdef USE_LIBRETINY
-#include "logger.h"
-
-namespace esphome::logger {
-
-static const char *const TAG = "logger";
-
-void Logger::pre_setup() {
-  if (this->baud_rate_ > 0) {
-    switch (this->uart_) {
-#if LT_HW_UART0
-      case UART_SELECTION_UART0:
-        this->hw_serial_ = &Serial0;
-        Serial0.begin(this->baud_rate_);
-        break;
-#endif
-#if LT_HW_UART1
-      case UART_SELECTION_UART1:
-        this->hw_serial_ = &Serial1;
-        Serial1.begin(this->baud_rate_);
-        break;
-#endif
-#if LT_HW_UART2
-      case UART_SELECTION_UART2:
-        this->hw_serial_ = &Serial2;
-        Serial2.begin(this->baud_rate_);
-        break;
-#endif
-      default:
-        this->hw_serial_ = &Serial;
-        Serial.begin(this->baud_rate_);
-        if (this->uart_ != UART_SELECTION_DEFAULT) {
-          ESP_LOGW(TAG, "  The chosen logger UART port is not available on this board."
-                        "The default port was used instead.");
-        }
-        break;
-    }
-
-    // change lt_log() port to match default Serial
-    if (this->uart_ == UART_SELECTION_DEFAULT) {
-      this->uart_ = (UARTSelection) (LT_UART_DEFAULT_SERIAL + 1);
-      lt_log_set_port(LT_UART_DEFAULT_SERIAL);
-    } else {
-      lt_log_set_port(this->uart_ - 1);
-    }
-  }
-
-  global_logger = this;
-  ESP_LOGI(TAG, "Log initialized");
-}
-
-void HOT Logger::write_msg_(const char *msg) { this->hw_serial_->println(msg); }
-
-const LogString *Logger::get_uart_selection_() {
-  switch (this->uart_) {
-    case UART_SELECTION_DEFAULT:
-      return LOG_STR("DEFAULT");
-    case UART_SELECTION_UART0:
-      return LOG_STR("UART0");
-    case UART_SELECTION_UART1:
-      return LOG_STR("UART1");
-    case UART_SELECTION_UART2:
-    default:
-      return LOG_STR("UART2");
-  }
-}
-
-}  // namespace esphome::logger
-
-#endif  // USE_LIBRETINY

esphome/components/logger/logger_rp2040.cpp.bak

@@ -1,48 +0,0 @@
-#ifdef USE_RP2040
-#include "logger.h"
-#include "esphome/core/log.h"
-
-namespace esphome::logger {
-
-static const char *const TAG = "logger";
-
-void Logger::pre_setup() {
-  if (this->baud_rate_ > 0) {
-    switch (this->uart_) {
-      case UART_SELECTION_UART0:
-        this->hw_serial_ = &Serial1;
-        Serial1.begin(this->baud_rate_);
-        break;
-      case UART_SELECTION_UART1:
-        this->hw_serial_ = &Serial2;
-        Serial2.begin(this->baud_rate_);
-        break;
-      case UART_SELECTION_USB_CDC:
-        this->hw_serial_ = &Serial;
-        Serial.begin(this->baud_rate_);
-        break;
-    }
-  }
-  global_logger = this;
-  ESP_LOGI(TAG, "Log initialized");
-}
-
-void HOT Logger::write_msg_(const char *msg) { this->hw_serial_->println(msg); }
-
-const LogString *Logger::get_uart_selection_() {
-  switch (this->uart_) {
-    case UART_SELECTION_UART0:
-      return LOG_STR("UART0");
-    case UART_SELECTION_UART1:
-      return LOG_STR("UART1");
-#ifdef USE_LOGGER_USB_CDC
-    case UART_SELECTION_USB_CDC:
-      return LOG_STR("USB_CDC");
-#endif
-    default:
-      return LOG_STR("UNKNOWN");
-  }
-}
-
-}  // namespace esphome::logger
-#endif  // USE_RP2040

esphome/components/logger/logger_zephyr.cpp.bak

@@ -1,96 +0,0 @@
-#ifdef USE_ZEPHYR
-
-#include "esphome/core/application.h"
-#include "esphome/core/log.h"
-#include "logger.h"
-
-#include <zephyr/device.h>
-#include <zephyr/drivers/uart.h>
-#include <zephyr/usb/usb_device.h>
-
-namespace esphome::logger {
-
-static const char *const TAG = "logger";
-
-#ifdef USE_LOGGER_USB_CDC
-void Logger::loop() {
-  if (this->uart_ != UART_SELECTION_USB_CDC || nullptr == this->uart_dev_) {
-    return;
-  }
-  static bool opened = false;
-  uint32_t dtr = 0;
-  uart_line_ctrl_get(this->uart_dev_, UART_LINE_CTRL_DTR, &dtr);
-
-  /* Poll if the DTR flag was set, optional */
-  if (opened == dtr) {
-    return;
-  }
-
-  if (!opened) {
-    App.schedule_dump_config();
-  }
-  opened = !opened;
-}
-#endif
-
-void Logger::pre_setup() {
-  if (this->baud_rate_ > 0) {
-    static const struct device *uart_dev = nullptr;
-    switch (this->uart_) {
-      case UART_SELECTION_UART0:
-        uart_dev = DEVICE_DT_GET_OR_NULL(DT_NODELABEL(uart0));
-        break;
-      case UART_SELECTION_UART1:
-        uart_dev = DEVICE_DT_GET_OR_NULL(DT_NODELABEL(uart1));
-        break;
-#ifdef USE_LOGGER_USB_CDC
-      case UART_SELECTION_USB_CDC:
-        uart_dev = DEVICE_DT_GET_OR_NULL(DT_NODELABEL(cdc_acm_uart0));
-        if (device_is_ready(uart_dev)) {
-          usb_enable(nullptr);
-        }
-        break;
-#endif
-    }
-    if (!device_is_ready(uart_dev)) {
-      ESP_LOGE(TAG, "%s is not ready.", LOG_STR_ARG(get_uart_selection_()));
-    } else {
-      this->uart_dev_ = uart_dev;
-    }
-  }
-  global_logger = this;
-  ESP_LOGI(TAG, "Log initialized");
-}
-
-void HOT Logger::write_msg_(const char *msg) {
-#ifdef CONFIG_PRINTK
-  printk("%s\n", msg);
-#endif
-  if (nullptr == this->uart_dev_) {
-    return;
-  }
-  while (*msg) {
-    uart_poll_out(this->uart_dev_, *msg);
-    ++msg;
-  }
-  uart_poll_out(this->uart_dev_, '\n');
-}
-
-const LogString *Logger::get_uart_selection_() {
-  switch (this->uart_) {
-    case UART_SELECTION_UART0:
-      return LOG_STR("UART0");
-    case UART_SELECTION_UART1:
-      return LOG_STR("UART1");
-#ifdef USE_LOGGER_USB_CDC
-    case UART_SELECTION_USB_CDC:
-      return LOG_STR("USB_CDC");
-#endif
-    default:
-      return LOG_STR("UNKNOWN");
-  }
-}
-
-}  // namespace esphome::logger
-
-#endif

esphome/components/mcp23016/mcp23016.cpp

@@ -56,7 +56,7 @@ void MCP23016::pin_mode(uint8_t pin, gpio::Flags flags) {
     this->update_reg_(pin, false, iodir);
   }
 }
-float MCP23016::get_setup_priority() const { return setup_priority::IO; }
+float MCP23016::get_setup_priority() const { return setup_priority::HARDWARE; }
 bool MCP23016::read_reg_(uint8_t reg, uint8_t *value) {
   if (this->is_failed())
     return false;

esphome/components/mqtt/mqtt_client.cpp

@@ -540,8 +540,8 @@ bool MQTTClientComponent::publish(const char *topic, const char *payload, size_t
 }
 
 bool MQTTClientComponent::publish_json(const char *topic, const json::json_build_t &f, uint8_t qos, bool retain) {
-  auto message = json::build_json(f);
-  return this->publish(topic, message.c_str(), message.size(), qos, retain);
+  std::string message = json::build_json(f);
+  return this->publish(topic, message.c_str(), message.length(), qos, retain);
 }
 
 void MQTTClientComponent::enable() {

esphome/components/online_image/__init__.py

@@ -2,97 +2,34 @@ import logging
 
 from esphome import automation
 import esphome.codegen as cg
-from esphome.components.const import CONF_BYTE_ORDER, CONF_REQUEST_HEADERS
+from esphome.components import runtime_image
+from esphome.components.const import CONF_REQUEST_HEADERS
 from esphome.components.http_request import CONF_HTTP_REQUEST_ID, HttpRequestComponent
-from esphome.components.image import (
-    CONF_INVERT_ALPHA,
-    CONF_TRANSPARENCY,
-    IMAGE_SCHEMA,
-    Image_,
-    get_image_type_enum,
-    get_transparency_enum,
-    validate_settings,
-)
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_BUFFER_SIZE,
-    CONF_DITHER,
-    CONF_FILE,
-    CONF_FORMAT,
     CONF_ID,
     CONF_ON_ERROR,
-    CONF_RESIZE,
     CONF_TRIGGER_ID,
-    CONF_TYPE,
     CONF_URL,
 )
 from esphome.core import Lambda
 
-AUTO_LOAD = ["image"]
+AUTO_LOAD = ["image", "runtime_image"]
 DEPENDENCIES = ["display", "http_request"]
 CODEOWNERS = ["@guillempages", "@clydebarrow"]
 MULTI_CONF = True
 
 CONF_ON_DOWNLOAD_FINISHED = "on_download_finished"
-CONF_PLACEHOLDER = "placeholder"
 CONF_UPDATE = "update"
 
 _LOGGER = logging.getLogger(__name__)
 
 online_image_ns = cg.esphome_ns.namespace("online_image")
 
-ImageFormat = online_image_ns.enum("ImageFormat")
-
-
-class Format:
-    def __init__(self, image_type):
-        self.image_type = image_type
-
-    @property
-    def enum(self):
-        return getattr(ImageFormat, self.image_type)
-
-    def actions(self):
-        pass
-
-
-class BMPFormat(Format):
-    def __init__(self):
-        super().__init__("BMP")
-
-    def actions(self):
-        cg.add_define("USE_ONLINE_IMAGE_BMP_SUPPORT")
-
-
-class JPEGFormat(Format):
-    def __init__(self):
-        super().__init__("JPEG")
-
-    def actions(self):
-        cg.add_define("USE_ONLINE_IMAGE_JPEG_SUPPORT")
-        cg.add_library("JPEGDEC", None, "https://github.com/bitbank2/JPEGDEC#ca1e0f2")
-
-
-class PNGFormat(Format):
-    def __init__(self):
-        super().__init__("PNG")
-
-    def actions(self):
-        cg.add_define("USE_ONLINE_IMAGE_PNG_SUPPORT")
-        cg.add_library("pngle", "1.1.0")
-
-
-IMAGE_FORMATS = {
-    x.image_type: x
-    for x in (
-        BMPFormat(),
-        JPEGFormat(),
-        PNGFormat(),
-    )
-}
-IMAGE_FORMATS.update({"JPG": IMAGE_FORMATS["JPEG"]})
-
-OnlineImage = online_image_ns.class_("OnlineImage", cg.PollingComponent, Image_)
+OnlineImage = online_image_ns.class_(
+    "OnlineImage", cg.PollingComponent, runtime_image.RuntimeImage
+)
 
 # Actions
 SetUrlAction = online_image_ns.class_(
@@ -111,29 +48,17 @@ DownloadErrorTrigger = online_image_ns.class_(
 )
 
 
-def remove_options(*options):
-    return {
-        cv.Optional(option): cv.invalid(
-            f"{option} is an invalid option for online_image"
-        )
-        for option in options
-    }
-
-
 ONLINE_IMAGE_SCHEMA = (
-    IMAGE_SCHEMA.extend(remove_options(CONF_FILE, CONF_INVERT_ALPHA, CONF_DITHER))
+    runtime_image.runtime_image_schema(OnlineImage)
     .extend(
         {
-            cv.Required(CONF_ID): cv.declare_id(OnlineImage),
-            cv.GenerateID(CONF_HTTP_REQUEST_ID): cv.use_id(HttpRequestComponent),
             # Online Image specific options
+            cv.GenerateID(CONF_HTTP_REQUEST_ID): cv.use_id(HttpRequestComponent),
             cv.Required(CONF_URL): cv.url,
+            cv.Optional(CONF_BUFFER_SIZE, default=65536): cv.int_range(256, 65536),
             cv.Optional(CONF_REQUEST_HEADERS): cv.All(
                 cv.Schema({cv.string: cv.templatable(cv.string)})
             ),
-            cv.Required(CONF_FORMAT): cv.one_of(*IMAGE_FORMATS, upper=True),
-            cv.Optional(CONF_PLACEHOLDER): cv.use_id(Image_),
-            cv.Optional(CONF_BUFFER_SIZE, default=65536): cv.int_range(256, 65536),
             cv.Optional(CONF_ON_DOWNLOAD_FINISHED): automation.validate_automation(
                 {
                     cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(
@@ -162,7 +87,7 @@ CONFIG_SCHEMA = cv.Schema(
             rp2040_arduino=cv.Version(0, 0, 0),
             host=cv.Version(0, 0, 0),
         ),
-        validate_settings,
+        runtime_image.validate_runtime_image_settings,
     )
 )
 
@@ -199,23 +124,21 @@ async def online_image_action_to_code(config, action_id, template_arg, args):
 
 
 async def to_code(config):
-    image_format = IMAGE_FORMATS[config[CONF_FORMAT]]
-    image_format.actions()
+    # Use the enhanced helper function to get all runtime image parameters
+    settings = await runtime_image.process_runtime_image_config(config)
 
     url = config[CONF_URL]
-    width, height = config.get(CONF_RESIZE, (0, 0))
-    transparent = get_transparency_enum(config[CONF_TRANSPARENCY])
-
     var = cg.new_Pvariable(
         config[CONF_ID],
         url,
-        width,
-        height,
-        image_format.enum,
-        get_image_type_enum(config[CONF_TYPE]),
-        transparent,
+        settings.width,
+        settings.height,
+        settings.format_enum,
+        settings.image_type_enum,
+        settings.transparent,
+        settings.placeholder or cg.nullptr,
         config[CONF_BUFFER_SIZE],
-        config.get(CONF_BYTE_ORDER) != "LITTLE_ENDIAN",
+        settings.byte_order_big_endian,
     )
     await cg.register_component(var, config)
     await cg.register_parented(var, config[CONF_HTTP_REQUEST_ID])
@@ -227,10 +150,6 @@ async def to_code(config):
         else:
             cg.add(var.add_request_header(key, value))
 
-    if placeholder_id := config.get(CONF_PLACEHOLDER):
-        placeholder = await cg.get_variable(placeholder_id)
-        cg.add(var.set_placeholder(placeholder))
-
     for conf in config.get(CONF_ON_DOWNLOAD_FINISHED, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [(bool, "cached")], conf)

esphome/components/online_image/download_buffer.cpp

@@ -1,29 +1,10 @@
-#include "image_decoder.h"
-#include "online_image.h"
-
+#include "download_buffer.h"
 #include "esphome/core/log.h"
+#include <cstring>
 
-namespace esphome {
-namespace online_image {
+namespace esphome::online_image {
 
-static const char *const TAG = "online_image.decoder";
-
-bool ImageDecoder::set_size(int width, int height) {
-  bool success = this->image_->resize_(width, height) > 0;
-  this->x_scale_ = static_cast<double>(this->image_->buffer_width_) / width;
-  this->y_scale_ = static_cast<double>(this->image_->buffer_height_) / height;
-  return success;
-}
-
-void ImageDecoder::draw(int x, int y, int w, int h, const Color &color) {
-  auto width = std::min(this->image_->buffer_width_, static_cast<int>(std::ceil((x + w) * this->x_scale_)));
-  auto height = std::min(this->image_->buffer_height_, static_cast<int>(std::ceil((y + h) * this->y_scale_)));
-  for (int i = x * this->x_scale_; i < width; i++) {
-    for (int j = y * this->y_scale_; j < height; j++) {
-      this->image_->draw_pixel_(i, j, color);
-    }
-  }
-}
+static const char *const TAG = "online_image.download_buffer";
 
 DownloadBuffer::DownloadBuffer(size_t size) : size_(size) {
   this->buffer_ = this->allocator_.allocate(size);
@@ -43,10 +24,12 @@ uint8_t *DownloadBuffer::data(size_t offset) {
 }
 
 size_t DownloadBuffer::read(size_t len) {
-  this->unread_ -= len;
-  if (this->unread_ > 0) {
-    memmove(this->data(), this->data(len), this->unread_);
+  if (len >= this->unread_) {
+    this->unread_ = 0;
+    return 0;
   }
+  this->unread_ -= len;
+  memmove(this->data(), this->data(len), this->unread_);
   return this->unread_;
 }
 
@@ -69,5 +52,4 @@ size_t DownloadBuffer::resize(size_t size) {
   }
 }
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::online_image

esphome/components/online_image/download_buffer.h

@@ -0,0 +1,44 @@
+#pragma once
+
+#include "esphome/core/helpers.h"
+#include <cstddef>
+#include <cstdint>
+
+namespace esphome::online_image {
+
+/**
+ * @brief Buffer for managing downloaded data.
+ *
+ * This class provides a buffer for downloading data with tracking of
+ * unread bytes and dynamic resizing capabilities.
+ */
+class DownloadBuffer {
+ public:
+  DownloadBuffer(size_t size);
+  ~DownloadBuffer() { this->allocator_.deallocate(this->buffer_, this->size_); }
+
+  uint8_t *data(size_t offset = 0);
+  uint8_t *append() { return this->data(this->unread_); }
+
+  size_t unread() const { return this->unread_; }
+  size_t size() const { return this->size_; }
+  size_t free_capacity() const { return this->size_ - this->unread_; }
+
+  size_t read(size_t len);
+  size_t write(size_t len) {
+    this->unread_ += len;
+    return this->unread_;
+  }
+
+  void reset() { this->unread_ = 0; }
+  size_t resize(size_t size);
+
+ protected:
+  RAMAllocator<uint8_t> allocator_{};
+  uint8_t *buffer_;
+  size_t size_;
+  /** Total number of downloaded bytes not yet read. */
+  size_t unread_;
+};
+
+}  // namespace esphome::online_image

esphome/components/online_image/online_image.cpp

@@ -1,6 +1,6 @@
 #include "online_image.h"
-
 #include "esphome/core/log.h"
+#include <algorithm>
 
 static const char *const TAG = "online_image";
 static const char *const ETAG_HEADER_NAME = "etag";
@@ -8,142 +8,82 @@ static const char *const IF_NONE_MATCH_HEADER_NAME = "if-none-match";
 static const char *const LAST_MODIFIED_HEADER_NAME = "last-modified";
 static const char *const IF_MODIFIED_SINCE_HEADER_NAME = "if-modified-since";
 
-#include "image_decoder.h"
+namespace esphome::online_image {
 
-#ifdef USE_ONLINE_IMAGE_BMP_SUPPORT
-#include "bmp_image.h"
-#endif
-#ifdef USE_ONLINE_IMAGE_JPEG_SUPPORT
-#include "jpeg_image.h"
-#endif
-#ifdef USE_ONLINE_IMAGE_PNG_SUPPORT
-#include "png_image.h"
-#endif
-
-namespace esphome {
-namespace online_image {
-
-using image::ImageType;
-
-inline bool is_color_on(const Color &color) {
-  // This produces the most accurate monochrome conversion, but is slightly slower.
-  //  return (0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b) > 127;
-
-  // Approximation using fast integer computations; produces acceptable results
-  // Equivalent to 0.25 * R + 0.5 * G + 0.25 * B
-  return ((color.r >> 2) + (color.g >> 1) + (color.b >> 2)) & 0x80;
-}
-
-OnlineImage::OnlineImage(const std::string &url, int width, int height, ImageFormat format, ImageType type,
-                         image::Transparency transparency, uint32_t download_buffer_size, bool is_big_endian)
-    : Image(nullptr, 0, 0, type, transparency),
-      buffer_(nullptr),
-      download_buffer_(download_buffer_size),
-      download_buffer_initial_size_(download_buffer_size),
-      format_(format),
-      fixed_width_(width),
-      fixed_height_(height),
-      is_big_endian_(is_big_endian) {
+OnlineImage::OnlineImage(const std::string &url, int width, int height, runtime_image::ImageFormat format,
+                         image::ImageType type, image::Transparency transparency, image::Image *placeholder,
+                         uint32_t buffer_size, bool is_big_endian)
+    : RuntimeImage(format, type, transparency, placeholder, is_big_endian, width, height),
+      download_buffer_(buffer_size),
+      download_buffer_initial_size_(buffer_size) {
   this->set_url(url);
 }
 
-void OnlineImage::draw(int x, int y, display::Display *display, Color color_on, Color color_off) {
-  if (this->data_start_) {
-    Image::draw(x, y, display, color_on, color_off);
-  } else if (this->placeholder_) {
-    this->placeholder_->draw(x, y, display, color_on, color_off);
+bool OnlineImage::validate_url_(const std::string &url) {
+  if (url.empty()) {
+    ESP_LOGE(TAG, "URL is empty");
+    return false;
   }
-}
-
-void OnlineImage::release() {
-  if (this->buffer_) {
-    ESP_LOGV(TAG, "Deallocating old buffer");
-    this->allocator_.deallocate(this->buffer_, this->get_buffer_size_());
-    this->data_start_ = nullptr;
-    this->buffer_ = nullptr;
-    this->width_ = 0;
-    this->height_ = 0;
-    this->buffer_width_ = 0;
-    this->buffer_height_ = 0;
-    this->last_modified_ = "";
-    this->etag_ = "";
-    this->end_connection_();
+  if (url.length() > 2048) {
+    ESP_LOGE(TAG, "URL is too long");
+    return false;
   }
-}
-
-size_t OnlineImage::resize_(int width_in, int height_in) {
-  int width = this->fixed_width_;
-  int height = this->fixed_height_;
-  if (this->is_auto_resize_()) {
-    width = width_in;
-    height = height_in;
-    if (this->width_ != width && this->height_ != height) {
-      this->release();
-    }
+  if (url.compare(0, 7, "http://") != 0 && url.compare(0, 8, "https://") != 0) {
+    ESP_LOGE(TAG, "URL must start with http:// or https://");
+    return false;
   }
-  size_t new_size = this->get_buffer_size_(width, height);
-  if (this->buffer_) {
-    // Buffer already allocated => no need to resize
-    return new_size;
-  }
-  ESP_LOGD(TAG, "Allocating new buffer of %zu bytes", new_size);
-  this->buffer_ = this->allocator_.allocate(new_size);
-  if (this->buffer_ == nullptr) {
-    ESP_LOGE(TAG, "allocation of %zu bytes failed. Biggest block in heap: %zu Bytes", new_size,
-             this->allocator_.get_max_free_block_size());
-    this->end_connection_();
-    return 0;
-  }
-  this->buffer_width_ = width;
-  this->buffer_height_ = height;
-  this->width_ = width;
-  ESP_LOGV(TAG, "New size: (%d, %d)", width, height);
-  return new_size;
+  return true;
 }
 
 void OnlineImage::update() {
-  if (this->decoder_) {
+  if (this->is_decoding()) {
     ESP_LOGW(TAG, "Image already being updated.");
     return;
   }
-  ESP_LOGI(TAG, "Updating image %s", this->url_.c_str());
 
-  std::list<http_request::Header> headers = {};
-
-  http_request::Header accept_header;
-  accept_header.name = "Accept";
-  std::string accept_mime_type;
-  switch (this->format_) {
-#ifdef USE_ONLINE_IMAGE_BMP_SUPPORT
-    case ImageFormat::BMP:
-      accept_mime_type = "image/bmp";
-      break;
-#endif  // USE_ONLINE_IMAGE_BMP_SUPPORT
-#ifdef USE_ONLINE_IMAGE_JPEG_SUPPORT
-    case ImageFormat::JPEG:
-      accept_mime_type = "image/jpeg";
-      break;
-#endif  // USE_ONLINE_IMAGE_JPEG_SUPPORT
-#ifdef USE_ONLINE_IMAGE_PNG_SUPPORT
-    case ImageFormat::PNG:
-      accept_mime_type = "image/png";
-      break;
-#endif  // USE_ONLINE_IMAGE_PNG_SUPPORT
-    default:
-      accept_mime_type = "image/*";
+  if (!this->validate_url_(this->url_)) {
+    ESP_LOGE(TAG, "Invalid URL: %s", this->url_.c_str());
+    this->download_error_callback_.call();
+    return;
   }
-  accept_header.value = accept_mime_type + ",*/*;q=0.8";
 
+  ESP_LOGD(TAG, "Updating image from %s", this->url_.c_str());
+
+  std::list<http_request::Header> headers;
+
+  // Add caching headers if we have them
   if (!this->etag_.empty()) {
-    headers.push_back(http_request::Header{IF_NONE_MATCH_HEADER_NAME, this->etag_});
+    headers.push_back({IF_NONE_MATCH_HEADER_NAME, this->etag_});
   }
-
   if (!this->last_modified_.empty()) {
-    headers.push_back(http_request::Header{IF_MODIFIED_SINCE_HEADER_NAME, this->last_modified_});
+    headers.push_back({IF_MODIFIED_SINCE_HEADER_NAME, this->last_modified_});
   }
 
-  headers.push_back(accept_header);
+  // Add Accept header based on image format
+  const char *accept_mime_type;
+  switch (this->get_format()) {
+#ifdef USE_RUNTIME_IMAGE_BMP
+    case runtime_image::BMP:
+      accept_mime_type = "image/bmp,*/*;q=0.8";
+      break;
+#endif
+#ifdef USE_RUNTIME_IMAGE_JPEG
+    case runtime_image::JPEG:
+      accept_mime_type = "image/jpeg,*/*;q=0.8";
+      break;
+#endif
+#ifdef USE_RUNTIME_IMAGE_PNG
+    case runtime_image::PNG:
+      accept_mime_type = "image/png,*/*;q=0.8";
+      break;
+#endif
+    default:
+      accept_mime_type = "image/*,*/*;q=0.8";
+      break;
+  }
+  headers.push_back({"Accept", accept_mime_type});
 
+  // User headers last so they can override any of the above
   for (auto &header : this->request_headers_) {
     headers.push_back(http_request::Header{header.first, header.second.value()});
   }
@@ -175,186 +115,117 @@ void OnlineImage::update() {
   ESP_LOGD(TAG, "Starting download");
   size_t total_size = this->downloader_->content_length;
 
-#ifdef USE_ONLINE_IMAGE_BMP_SUPPORT
-  if (this->format_ == ImageFormat::BMP) {
-    ESP_LOGD(TAG, "Allocating BMP decoder");
-    this->decoder_ = make_unique<BmpDecoder>(this);
-    this->enable_loop();
+  // Initialize decoder with the known format
+  if (!this->begin_decode(total_size)) {
+    ESP_LOGE(TAG, "Failed to initialize decoder for format %d", this->get_format());
+    this->end_connection_();
+    this->download_error_callback_.call();
+    return;
   }
-#endif  // USE_ONLINE_IMAGE_BMP_SUPPORT
-#ifdef USE_ONLINE_IMAGE_JPEG_SUPPORT
-  if (this->format_ == ImageFormat::JPEG) {
-    ESP_LOGD(TAG, "Allocating JPEG decoder");
-    this->decoder_ = esphome::make_unique<JpegDecoder>(this);
-    this->enable_loop();
-  }
-#endif  // USE_ONLINE_IMAGE_JPEG_SUPPORT
-#ifdef USE_ONLINE_IMAGE_PNG_SUPPORT
-  if (this->format_ == ImageFormat::PNG) {
-    ESP_LOGD(TAG, "Allocating PNG decoder");
-    this->decoder_ = make_unique<PngDecoder>(this);
-    this->enable_loop();
-  }
-#endif  // USE_ONLINE_IMAGE_PNG_SUPPORT
 
-  if (!this->decoder_) {
-    ESP_LOGE(TAG, "Could not instantiate decoder. Image format unsupported: %d", this->format_);
-    this->end_connection_();
-    this->download_error_callback_.call();
-    return;
-  }
-  auto prepare_result = this->decoder_->prepare(total_size);
-  if (prepare_result < 0) {
-    this->end_connection_();
-    this->download_error_callback_.call();
-    return;
+  // JPEG requires the complete image in the download buffer before decoding
+  if (this->get_format() == runtime_image::JPEG && total_size > this->download_buffer_.size()) {
+    this->download_buffer_.resize(total_size);
   }
+
   ESP_LOGI(TAG, "Downloading image (Size: %zu)", total_size);
   this->start_time_ = ::time(nullptr);
+  this->enable_loop();
 }
 
 void OnlineImage::loop() {
-  if (!this->decoder_) {
+  if (!this->is_decoding()) {
     // Not decoding at the moment => nothing to do.
     this->disable_loop();
     return;
   }
-  if (!this->downloader_ || this->decoder_->is_finished()) {
-    this->data_start_ = buffer_;
-    this->width_ = buffer_width_;
-    this->height_ = buffer_height_;
-    ESP_LOGD(TAG, "Image fully downloaded, read %zu bytes, width/height = %d/%d", this->downloader_->get_bytes_read(),
-             this->width_, this->height_);
-    ESP_LOGD(TAG, "Total time: %" PRIu32 "s", (uint32_t) (::time(nullptr) - this->start_time_));
+
+  if (!this->downloader_) {
+    ESP_LOGE(TAG, "Downloader not instantiated; cannot download");
+    this->end_connection_();
+    this->download_error_callback_.call();
+    return;
+  }
+
+  // Check if download is complete — use decoder's format-specific completion check
+  // to handle both known content-length and chunked transfer encoding
+  if (this->is_decode_finished() || (this->downloader_->content_length > 0 &&
+                                     this->downloader_->get_bytes_read() >= this->downloader_->content_length &&
+                                     this->download_buffer_.unread() == 0)) {
+    // Finalize decoding
+    this->end_decode();
+
+    ESP_LOGD(TAG, "Image fully downloaded, %zu bytes in %" PRIu32 "s", this->downloader_->get_bytes_read(),
+             (uint32_t) (::time(nullptr) - this->start_time_));
+
+    // Save caching headers
     this->etag_ = this->downloader_->get_response_header(ETAG_HEADER_NAME);
     this->last_modified_ = this->downloader_->get_response_header(LAST_MODIFIED_HEADER_NAME);
+
     this->download_finished_callback_.call(false);
     this->end_connection_();
     return;
   }
-  if (this->downloader_ == nullptr) {
-    ESP_LOGE(TAG, "Downloader not instantiated; cannot download");
-    return;
-  }
+
+  // Download and decode more data
   size_t available = this->download_buffer_.free_capacity();
-  if (available) {
-    // Some decoders need to fully download the image before downloading.
-    // In case of huge images, don't wait blocking until the whole image has been downloaded,
-    // use smaller chunks
+  if (available > 0) {
+    // Download in chunks to avoid blocking
     available = std::min(available, this->download_buffer_initial_size_);
     auto len = this->downloader_->read(this->download_buffer_.append(), available);
+
     if (len > 0) {
       this->download_buffer_.write(len);
-      auto fed = this->decoder_->decode(this->download_buffer_.data(), this->download_buffer_.unread());
-      if (fed < 0) {
-        ESP_LOGE(TAG, "Error when decoding image.");
+
+      // Feed data to decoder
+      auto consumed = this->feed_data(this->download_buffer_.data(), this->download_buffer_.unread());
+
+      if (consumed < 0) {
+        ESP_LOGE(TAG, "Error decoding image: %d", consumed);
         this->end_connection_();
         this->download_error_callback_.call();
         return;
       }
-      this->download_buffer_.read(fed);
-    }
-  }
-}
 
-void OnlineImage::map_chroma_key(Color &color) {
-  if (this->transparency_ == image::TRANSPARENCY_CHROMA_KEY) {
-    if (color.g == 1 && color.r == 0 && color.b == 0) {
-      color.g = 0;
-    }
-    if (color.w < 0x80) {
-      color.r = 0;
-      color.g = this->type_ == ImageType::IMAGE_TYPE_RGB565 ? 4 : 1;
-      color.b = 0;
-    }
-  }
-}
-
-void OnlineImage::draw_pixel_(int x, int y, Color color) {
-  if (!this->buffer_) {
-    ESP_LOGE(TAG, "Buffer not allocated!");
-    return;
-  }
-  if (x < 0 || y < 0 || x >= this->buffer_width_ || y >= this->buffer_height_) {
-    ESP_LOGE(TAG, "Tried to paint a pixel (%d,%d) outside the image!", x, y);
-    return;
-  }
-  uint32_t pos = this->get_position_(x, y);
-  switch (this->type_) {
-    case ImageType::IMAGE_TYPE_BINARY: {
-      const uint32_t width_8 = ((this->width_ + 7u) / 8u) * 8u;
-      pos = x + y * width_8;
-      auto bitno = 0x80 >> (pos % 8u);
-      pos /= 8u;
-      auto on = is_color_on(color);
-      if (this->has_transparency() && color.w < 0x80)
-        on = false;
-      if (on) {
-        this->buffer_[pos] |= bitno;
-      } else {
-        this->buffer_[pos] &= ~bitno;
+      if (consumed > 0) {
+        this->download_buffer_.read(consumed);
       }
-      break;
+    } else if (len < 0) {
+      ESP_LOGE(TAG, "Error downloading image: %d", len);
+      this->end_connection_();
+      this->download_error_callback_.call();
+      return;
     }
-    case ImageType::IMAGE_TYPE_GRAYSCALE: {
-      auto gray = static_cast<uint8_t>(0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b);
-      if (this->transparency_ == image::TRANSPARENCY_CHROMA_KEY) {
-        if (gray == 1) {
-          gray = 0;
-        }
-        if (color.w < 0x80) {
-          gray = 1;
-        }
-      } else if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
-        if (color.w != 0xFF)
-          gray = color.w;
-      }
-      this->buffer_[pos] = gray;
-      break;
-    }
-    case ImageType::IMAGE_TYPE_RGB565: {
-      this->map_chroma_key(color);
-      uint16_t col565 = display::ColorUtil::color_to_565(color);
-      if (this->is_big_endian_) {
-        this->buffer_[pos + 0] = static_cast<uint8_t>((col565 >> 8) & 0xFF);
-        this->buffer_[pos + 1] = static_cast<uint8_t>(col565 & 0xFF);
-      } else {
-        this->buffer_[pos + 0] = static_cast<uint8_t>(col565 & 0xFF);
-        this->buffer_[pos + 1] = static_cast<uint8_t>((col565 >> 8) & 0xFF);
-      }
-      if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
-        this->buffer_[pos + 2] = color.w;
-      }
-      break;
-    }
-    case ImageType::IMAGE_TYPE_RGB: {
-      this->map_chroma_key(color);
-      this->buffer_[pos + 0] = color.r;
-      this->buffer_[pos + 1] = color.g;
-      this->buffer_[pos + 2] = color.b;
-      if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
-        this->buffer_[pos + 3] = color.w;
-      }
-      break;
+  } else {
+    // Buffer is full, need to decode some data first
+    auto consumed = this->feed_data(this->download_buffer_.data(), this->download_buffer_.unread());
+    if (consumed > 0) {
+      this->download_buffer_.read(consumed);
+    } else if (consumed < 0) {
+      ESP_LOGE(TAG, "Decode error with full buffer: %d", consumed);
+      this->end_connection_();
+      this->download_error_callback_.call();
+      return;
+    } else {
+      // Decoder can't process more data, might need complete image
+      // This is normal for JPEG which needs complete data
+      ESP_LOGV(TAG, "Decoder waiting for more data");
     }
   }
 }
 
 void OnlineImage::end_connection_() {
+  // Abort any in-progress decode to free decoder resources.
+  // Use RuntimeImage::release() directly to avoid recursion with OnlineImage::release().
+  if (this->is_decoding()) {
+    RuntimeImage::release();
+  }
   if (this->downloader_) {
     this->downloader_->end();
     this->downloader_ = nullptr;
   }
-  this->decoder_.reset();
   this->download_buffer_.reset();
-}
-
-bool OnlineImage::validate_url_(const std::string &url) {
-  if ((url.length() < 8) || !url.starts_with("http") || (url.find("://") == std::string::npos)) {
-    ESP_LOGE(TAG, "URL is invalid and/or must be prefixed with 'http://' or 'https://'");
-    return false;
-  }
-  return true;
+  this->disable_loop();
 }
 
 void OnlineImage::add_on_finished_callback(std::function<void(bool)> &&callback) {
@@ -365,5 +236,16 @@ void OnlineImage::add_on_error_callback(std::function<void()> &&callback) {
   this->download_error_callback_.add(std::move(callback));
 }
 
-}  // namespace online_image
-}  // namespace esphome
+void OnlineImage::release() {
+  // Clear cache headers
+  this->etag_ = "";
+  this->last_modified_ = "";
+
+  // End any active connection
+  this->end_connection_();
+
+  // Call parent's release to free the image buffer
+  RuntimeImage::release();
+}
+
+}  // namespace esphome::online_image

esphome/components/online_image/online_image.h

@@ -1,15 +1,14 @@
 #pragma once
 
+#include "download_buffer.h"
 #include "esphome/components/http_request/http_request.h"
-#include "esphome/components/image/image.h"
+#include "esphome/components/runtime_image/runtime_image.h"
+#include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 
-#include "image_decoder.h"
-
-namespace esphome {
-namespace online_image {
+namespace esphome::online_image {
 
 using t_http_codes = enum {
   HTTP_CODE_OK = 200,
@@ -17,27 +16,13 @@ using t_http_codes = enum {
   HTTP_CODE_NOT_FOUND = 404,
 };
 
-/**
- * @brief Format that the image is encoded with.
- */
-enum ImageFormat {
-  /** Automatically detect from MIME type. Not supported yet. */
-  AUTO,
-  /** JPEG format. */
-  JPEG,
-  /** PNG format. */
-  PNG,
-  /** BMP format. */
-  BMP,
-};
-
 /**
  * @brief Download an image from a given URL, and decode it using the specified decoder.
  * The image will then be stored in a buffer, so that it can be re-displayed without the
  * need to re-download or re-decode.
  */
 class OnlineImage : public PollingComponent,
-                    public image::Image,
+                    public runtime_image::RuntimeImage,
                     public Parented<esphome::http_request::HttpRequestComponent> {
  public:
   /**
@@ -46,17 +31,19 @@ class OnlineImage : public PollingComponent,
    * @param url URL to download the image from.
    * @param width Desired width of the target image area.
    * @param height Desired height of the target image area.
-   * @param format Format that the image is encoded in (@see ImageFormat).
+   * @param format Format that the image is encoded in (@see runtime_image::ImageFormat).
+   * @param type The pixel format for the image.
+   * @param transparency The transparency type for the image.
+   * @param placeholder Optional placeholder image to show while loading.
    * @param buffer_size Size of the buffer used to download the image.
+   * @param is_big_endian Whether the image is stored in big-endian format.
    */
-  OnlineImage(const std::string &url, int width, int height, ImageFormat format, image::ImageType type,
-              image::Transparency transparency, uint32_t buffer_size, bool is_big_endian);
-
-  void draw(int x, int y, display::Display *display, Color color_on, Color color_off) override;
+  OnlineImage(const std::string &url, int width, int height, runtime_image::ImageFormat format, image::ImageType type,
+              image::Transparency transparency, image::Image *placeholder, uint32_t buffer_size,
+              bool is_big_endian = false);
 
   void update() override;
   void loop() override;
-  void map_chroma_key(Color &color);
 
   /** Set the URL to download the image from. */
   void set_url(const std::string &url) {
@@ -69,82 +56,26 @@ class OnlineImage : public PollingComponent,
 
   /** Add the request header */
   template<typename V> void add_request_header(const std::string &header, V value) {
-    this->request_headers_.push_back(std::pair<std::string, TemplatableValue<std::string> >(header, value));
+    this->request_headers_.push_back(std::pair<std::string, TemplatableValue<std::string>>(header, value));
   }
 
-  /**
-   * @brief Set the image that needs to be shown as long as the downloaded image
-   *  is not available.
-   *
-   * @param placeholder Pointer to the (@link Image) to show as placeholder.
-   */
-  void set_placeholder(image::Image *placeholder) { this->placeholder_ = placeholder; }
-
   /**
    * Release the buffer storing the image. The image will need to be downloaded again
    * to be able to be displayed.
    */
   void release();
 
-  /**
-   * Resize the download buffer
-   *
-   * @param size The new size for the download buffer.
-   */
-  size_t resize_download_buffer(size_t size) { return this->download_buffer_.resize(size); }
-
   void add_on_finished_callback(std::function<void(bool)> &&callback);
   void add_on_error_callback(std::function<void()> &&callback);
 
  protected:
   bool validate_url_(const std::string &url);
-
-  RAMAllocator<uint8_t> allocator_{};
-
-  uint32_t get_buffer_size_() const { return get_buffer_size_(this->buffer_width_, this->buffer_height_); }
-  int get_buffer_size_(int width, int height) const { return (this->get_bpp() * width + 7u) / 8u * height; }
-
-  int get_position_(int x, int y) const { return (x + y * this->buffer_width_) * this->get_bpp() / 8; }
-
-  ESPHOME_ALWAYS_INLINE bool is_auto_resize_() const { return this->fixed_width_ == 0 || this->fixed_height_ == 0; }
-
-  /**
-   * @brief Resize the image buffer to the requested dimensions.
-   *
-   * The buffer will be allocated if not existing.
-   * If the dimensions have been fixed in the yaml config, the buffer will be created
-   * with those dimensions and not resized, even on request.
-   * Otherwise, the old buffer will be deallocated and a new buffer with the requested
-   * allocated
-   *
-   * @param width
-   * @param height
-   * @return 0 if no memory could be allocated, the size of the new buffer otherwise.
-   */
-  size_t resize_(int width, int height);
-
-  /**
-   * @brief Draw a pixel into the buffer.
-   *
-   * This is used by the decoder to fill the buffer that will later be displayed
-   * by the `draw` method. This will internally convert the supplied 32 bit RGBA
-   * color into the requested image storage format.
-   *
-   * @param x Horizontal pixel position.
-   * @param y Vertical pixel position.
-   * @param color 32 bit color to put into the pixel.
-   */
-  void draw_pixel_(int x, int y, Color color);
-
   void end_connection_();
 
   CallbackManager<void(bool)> download_finished_callback_{};
   CallbackManager<void()> download_error_callback_{};
 
   std::shared_ptr<http_request::HttpContainer> downloader_{nullptr};
-  std::unique_ptr<ImageDecoder> decoder_{nullptr};
-
-  uint8_t *buffer_;
   DownloadBuffer download_buffer_;
   /**
    * This is the *initial* size of the download buffer, not the current size.
@@ -153,40 +84,10 @@ class OnlineImage : public PollingComponent,
    */
   size_t download_buffer_initial_size_;
 
-  const ImageFormat format_;
-  image::Image *placeholder_{nullptr};
-
   std::string url_{""};
 
-  std::vector<std::pair<std::string, TemplatableValue<std::string> > > request_headers_;
+  std::vector<std::pair<std::string, TemplatableValue<std::string>>> request_headers_;
 
-  /** width requested on configuration, or 0 if non specified. */
-  const int fixed_width_;
-  /** height requested on configuration, or 0 if non specified. */
-  const int fixed_height_;
-  /**
-   * Whether the image is stored in big-endian format.
-   * This is used to determine how to store 16 bit colors in the buffer.
-   */
-  bool is_big_endian_;
-  /**
-   * Actual width of the current image. If fixed_width_ is specified,
-   * this will be equal to it; otherwise it will be set once the decoding
-   * starts and the original size is known.
-   * This needs to be separate from "BaseImage::get_width()" because the latter
-   * must return 0 until the image has been decoded (to avoid showing partially
-   * decoded images).
-   */
-  int buffer_width_;
-  /**
-   * Actual height of the current image. If fixed_height_ is specified,
-   * this will be equal to it; otherwise it will be set once the decoding
-   * starts and the original size is known.
-   * This needs to be separate from "BaseImage::get_height()" because the latter
-   * must return 0 until the image has been decoded (to avoid showing partially
-   * decoded images).
-   */
-  int buffer_height_;
   /**
    * The value of the ETag HTTP header provided in the last response.
    */
@@ -197,9 +98,6 @@ class OnlineImage : public PollingComponent,
   std::string last_modified_ = "";
 
   time_t start_time_;
-
-  friend bool ImageDecoder::set_size(int width, int height);
-  friend void ImageDecoder::draw(int x, int y, int w, int h, const Color &color);
 };
 
 template<typename... Ts> class OnlineImageSetUrlAction : public Action<Ts...> {
@@ -241,5 +139,4 @@ class DownloadErrorTrigger : public Trigger<> {
   }
 };
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::online_image

esphome/components/pn532/pn532.h

@@ -76,7 +76,7 @@ class PN532 : public PollingComponent {
 
   std::unique_ptr<nfc::NfcTag> read_mifare_classic_tag_(nfc::NfcTagUid &uid);
   bool read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  bool write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
+  bool write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
   bool auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key);
   bool format_mifare_classic_mifare_(nfc::NfcTagUid &uid);
   bool format_mifare_classic_ndef_(nfc::NfcTagUid &uid);
@@ -88,7 +88,7 @@ class PN532 : public PollingComponent {
   uint16_t read_mifare_ultralight_capacity_();
   bool find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                     uint8_t &message_start_index);
-  bool write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
+  bool write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
   bool write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message);
   bool clean_mifare_ultralight_();
 

esphome/components/pn532/pn532_mifare_classic.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <memory>
 
 #include "pn532.h"
@@ -107,10 +106,10 @@ bool PN532::auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, u
 }
 
 bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
-      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> blank_buffer(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> trailer_buffer(
+      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   bool error = false;
 
@@ -119,20 +118,20 @@ bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
       continue;
     }
     if (block != 0) {
-      if (!this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
+      if (!this->write_mifare_classic_block_(block, blank_buffer)) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
         error = true;
       }
     }
-    if (!this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
+    if (!this->write_mifare_classic_block_(block + 1, blank_buffer)) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 1);
       error = true;
     }
-    if (!this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
+    if (!this->write_mifare_classic_block_(block + 2, blank_buffer)) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 2);
       error = true;
     }
-    if (!this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size())) {
+    if (!this->write_mifare_classic_block_(block + 3, trailer_buffer)) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 3);
       error = true;
     }
@@ -142,28 +141,28 @@ bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
 }
 
 bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
-      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
-      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
-      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
-      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
-      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> empty_ndef_message(
+      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> blank_block(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> block_1_data(
+      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_2_data(
+      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_3_trailer(
+      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  std::vector<uint8_t> ndef_trailer(
+      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   if (!this->auth_mifare_classic_block_(uid, 0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY)) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting!");
     return false;
   }
-  if (!this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()))
+  if (!this->write_mifare_classic_block_(1, block_1_data))
     return false;
-  if (!this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()))
+  if (!this->write_mifare_classic_block_(2, block_2_data))
     return false;
-  if (!this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()))
+  if (!this->write_mifare_classic_block_(3, block_3_trailer))
     return false;
 
   ESP_LOGD(TAG, "Sector 0 formatted to NDEF");
@@ -173,36 +172,36 @@ bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
       return false;
     }
     if (block == 4) {
-      if (!this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size())) {
+      if (!this->write_mifare_classic_block_(block, empty_ndef_message)) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
       }
     } else {
-      if (!this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
+      if (!this->write_mifare_classic_block_(block, blank_block)) {
         ESP_LOGE(TAG, "Unable to write block %d", block);
       }
     }
-    if (!this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
+    if (!this->write_mifare_classic_block_(block + 1, blank_block)) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 1);
     }
-    if (!this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
+    if (!this->write_mifare_classic_block_(block + 2, blank_block)) {
       ESP_LOGE(TAG, "Unable to write block %d", block + 2);
     }
-    if (!this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size())) {
+    if (!this->write_mifare_classic_block_(block + 3, ndef_trailer)) {
       ESP_LOGE(TAG, "Unable to write trailer block %d", block + 3);
     }
   }
   return true;
 }
 
-bool PN532::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
-  std::vector<uint8_t> cmd({
+bool PN532::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
+  std::vector<uint8_t> data({
       PN532_COMMAND_INDATAEXCHANGE,
       0x01,  // One card
       nfc::MIFARE_CMD_WRITE,
       block_num,
   });
-  cmd.insert(cmd.end(), data, data + len);
-  if (!this->write_command_(cmd)) {
+  data.insert(data.end(), write_data.begin(), write_data.end());
+  if (!this->write_command_(data)) {
     ESP_LOGE(TAG, "Error writing block %d", block_num);
     return false;
   }
@@ -244,7 +243,8 @@ bool PN532::write_mifare_classic_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *mes
       }
     }
 
-    if (!this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE)) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
+    if (!this->write_mifare_classic_block_(current_block, data)) {
       return false;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn532/pn532_mifare_ultralight.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <memory>
 
 #include "pn532.h"
@@ -144,7 +143,8 @@ bool PN532::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    if (!this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE)) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
+    if (!this->write_mifare_ultralight_page_(current_page, data)) {
       return false;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -157,25 +157,25 @@ bool PN532::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
+  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (!this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size())) {
+    if (!this->write_mifare_ultralight_page_(i, blank_data)) {
       return false;
     }
   }
   return true;
 }
 
-bool PN532::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
-  std::vector<uint8_t> cmd({
+bool PN532::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
+  std::vector<uint8_t> data({
       PN532_COMMAND_INDATAEXCHANGE,
       0x01,  // One card
       nfc::MIFARE_CMD_WRITE_ULTRALIGHT,
       page_num,
   });
-  cmd.insert(cmd.end(), write_data, write_data + len);
-  if (!this->write_command_(cmd)) {
+  data.insert(data.end(), write_data.begin(), write_data.end());
+  if (!this->write_command_(data)) {
     ESP_LOGE(TAG, "Error writing page %u", page_num);
     return false;
   }

esphome/components/pn7150/pn7150.h

@@ -236,7 +236,7 @@ class PN7150 : public nfc::Nfcc, public Component {
 
   uint8_t read_mifare_classic_tag_(nfc::NfcTag &tag);
   uint8_t read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  uint8_t write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
+  uint8_t write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
   uint8_t auth_mifare_classic_block_(uint8_t block_num, uint8_t key_num, const uint8_t *key);
   uint8_t sect_to_auth_(uint8_t block_num);
   uint8_t format_mifare_classic_mifare_();
@@ -250,7 +250,7 @@ class PN7150 : public nfc::Nfcc, public Component {
   uint16_t read_mifare_ultralight_capacity_();
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
-  uint8_t write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
+  uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
   uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 

esphome/components/pn7150/pn7150_mifare_classic.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <memory>
 
 #include "pn7150.h"
@@ -140,10 +139,10 @@ uint8_t PN7150::sect_to_auth_(const uint8_t block_num) {
 }
 
 uint8_t PN7150::format_mifare_classic_mifare_() {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
-      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> blank_buffer(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> trailer_buffer(
+      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   auto status = nfc::STATUS_OK;
 
@@ -152,20 +151,20 @@ uint8_t PN7150::format_mifare_classic_mifare_() {
       continue;
     }
     if (block != 0) {
-      if (this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, blank_buffer) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, blank_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, blank_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, trailer_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -175,30 +174,30 @@ uint8_t PN7150::format_mifare_classic_mifare_() {
 }
 
 uint8_t PN7150::format_mifare_classic_ndef_() {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
-      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
-      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
-      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
-      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
-      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> empty_ndef_message(
+      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> blank_block(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> block_1_data(
+      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_2_data(
+      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_3_trailer(
+      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  std::vector<uint8_t> ndef_trailer(
+      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   if (this->auth_mifare_classic_block_(0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY) != nfc::STATUS_OK) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting");
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(1, block_1_data) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(2, block_2_data) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(3, block_3_trailer) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
 
@@ -211,26 +210,25 @@ uint8_t PN7150::format_mifare_classic_ndef_() {
       return nfc::STATUS_FAILED;
     }
     if (block == 4) {
-      if (this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size()) !=
-          nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, empty_ndef_message) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     } else {
-      if (this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, blank_block) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, blank_block) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, blank_block) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, ndef_trailer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write trailer block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -238,7 +236,7 @@ uint8_t PN7150::format_mifare_classic_ndef_() {
   return status;
 }
 
-uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
+uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, {XCHG_DATA_OID, nfc::MIFARE_CMD_WRITE, block_num});
 
@@ -250,7 +248,7 @@ uint8_t PN7150::write_mifare_classic_block_(uint8_t block_num, const uint8_t *da
   }
   // write command part two
   tx.set_payload({XCHG_DATA_OID});
-  tx.get_message().insert(tx.get_message().end(), data, data + len);
+  tx.get_message().insert(tx.get_message().end(), write_data.begin(), write_data.end());
 
   ESP_LOGVV(TAG, "Write XCHG_DATA_REQ 2: %s", nfc::format_bytes_to(buf, tx.get_message()));
   if (this->transceive_(tx, rx, NFCC_TAG_WRITE_TIMEOUT) != nfc::STATUS_OK) {
@@ -296,8 +294,8 @@ uint8_t PN7150::write_mifare_classic_tag_(const std::shared_ptr<nfc::NdefMessage
       }
     }
 
-    if (this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE) !=
-        nfc::STATUS_OK) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
+    if (this->write_mifare_classic_block_(current_block, data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn7150/pn7150_mifare_ultralight.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <cinttypes>
 #include <memory>
 
@@ -145,8 +144,8 @@ uint8_t PN7150::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::sha
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    if (this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) !=
-        nfc::STATUS_OK) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
+    if (this->write_mifare_ultralight_page_(current_page, data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -159,19 +158,19 @@ uint8_t PN7150::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
+  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(i, blank_data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
   }
   return nfc::STATUS_OK;
 }
 
-uint8_t PN7150::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
+uint8_t PN7150::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
   std::vector<uint8_t> payload = {nfc::MIFARE_CMD_WRITE_ULTRALIGHT, page_num};
-  payload.insert(payload.end(), write_data, write_data + len);
+  payload.insert(payload.end(), write_data.begin(), write_data.end());
 
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, payload);

esphome/components/pn7160/pn7160.h

@@ -253,7 +253,7 @@ class PN7160 : public nfc::Nfcc, public Component {
 
   uint8_t read_mifare_classic_tag_(nfc::NfcTag &tag);
   uint8_t read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  uint8_t write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len);
+  uint8_t write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
   uint8_t auth_mifare_classic_block_(uint8_t block_num, uint8_t key_num, const uint8_t *key);
   uint8_t sect_to_auth_(uint8_t block_num);
   uint8_t format_mifare_classic_mifare_();
@@ -267,7 +267,7 @@ class PN7160 : public nfc::Nfcc, public Component {
   uint16_t read_mifare_ultralight_capacity_();
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
-  uint8_t write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len);
+  uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
   uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 

esphome/components/pn7160/pn7160_mifare_classic.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <memory>
 
 #include "pn7160.h"
@@ -140,10 +139,10 @@ uint8_t PN7160::sect_to_auth_(const uint8_t block_num) {
 }
 
 uint8_t PN7160::format_mifare_classic_mifare_() {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
-      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> blank_buffer(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> trailer_buffer(
+      {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   auto status = nfc::STATUS_OK;
 
@@ -152,20 +151,20 @@ uint8_t PN7160::format_mifare_classic_mifare_() {
       continue;
     }
     if (block != 0) {
-      if (this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, blank_buffer) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, blank_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, blank_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, trailer_buffer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -175,30 +174,30 @@ uint8_t PN7160::format_mifare_classic_mifare_() {
 }
 
 uint8_t PN7160::format_mifare_classic_ndef_() {
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
-      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
-      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
-      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
-      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
-      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  std::vector<uint8_t> empty_ndef_message(
+      {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> blank_block(
+      {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
+  std::vector<uint8_t> block_1_data(
+      {0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_2_data(
+      {0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1});
+  std::vector<uint8_t> block_3_trailer(
+      {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
+  std::vector<uint8_t> ndef_trailer(
+      {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF});
 
   if (this->auth_mifare_classic_block_(0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY) != nfc::STATUS_OK) {
     ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting");
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(1, block_1_data) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(2, block_2_data) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
-  if (this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()) != nfc::STATUS_OK) {
+  if (this->write_mifare_classic_block_(3, block_3_trailer) != nfc::STATUS_OK) {
     return nfc::STATUS_FAILED;
   }
 
@@ -211,26 +210,25 @@ uint8_t PN7160::format_mifare_classic_ndef_() {
       return nfc::STATUS_FAILED;
     }
     if (block == 4) {
-      if (this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size()) !=
-          nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, empty_ndef_message) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     } else {
-      if (this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+      if (this->write_mifare_classic_block_(block, blank_block) != nfc::STATUS_OK) {
         ESP_LOGE(TAG, "Unable to write block %u", block);
         status = nfc::STATUS_FAILED;
       }
     }
-    if (this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 1, blank_block) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 1);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 2, blank_block) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write block %u", block + 2);
       status = nfc::STATUS_FAILED;
     }
-    if (this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_classic_block_(block + 3, ndef_trailer) != nfc::STATUS_OK) {
       ESP_LOGE(TAG, "Unable to write trailer block %u", block + 3);
       status = nfc::STATUS_FAILED;
     }
@@ -238,7 +236,7 @@ uint8_t PN7160::format_mifare_classic_ndef_() {
   return status;
 }
 
-uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
+uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &write_data) {
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, {XCHG_DATA_OID, nfc::MIFARE_CMD_WRITE, block_num});
   char buf[nfc::FORMAT_BYTES_BUFFER_SIZE];
@@ -250,7 +248,7 @@ uint8_t PN7160::write_mifare_classic_block_(uint8_t block_num, const uint8_t *da
   }
   // write command part two
   tx.set_payload({XCHG_DATA_OID});
-  tx.get_message().insert(tx.get_message().end(), data, data + len);
+  tx.get_message().insert(tx.get_message().end(), write_data.begin(), write_data.end());
 
   ESP_LOGVV(TAG, "Write XCHG_DATA_REQ 2: %s", nfc::format_bytes_to(buf, tx.get_message()));
   if (this->transceive_(tx, rx, NFCC_TAG_WRITE_TIMEOUT) != nfc::STATUS_OK) {
@@ -296,8 +294,8 @@ uint8_t PN7160::write_mifare_classic_tag_(const std::shared_ptr<nfc::NdefMessage
       }
     }
 
-    if (this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE) !=
-        nfc::STATUS_OK) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_CLASSIC_BLOCK_SIZE);
+    if (this->write_mifare_classic_block_(current_block, data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;

esphome/components/pn7160/pn7160_mifare_ultralight.cpp

@@ -1,4 +1,3 @@
-#include <array>
 #include <cinttypes>
 #include <memory>
 
@@ -145,8 +144,8 @@ uint8_t PN7160::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::sha
   uint8_t current_page = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
   while (index < buffer_length) {
-    if (this->write_mifare_ultralight_page_(current_page, encoded.data() + index, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) !=
-        nfc::STATUS_OK) {
+    std::vector<uint8_t> data(encoded.begin() + index, encoded.begin() + index + nfc::MIFARE_ULTRALIGHT_PAGE_SIZE);
+    if (this->write_mifare_ultralight_page_(current_page, data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
     index += nfc::MIFARE_ULTRALIGHT_PAGE_SIZE;
@@ -159,19 +158,19 @@ uint8_t PN7160::clean_mifare_ultralight_() {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
   uint8_t pages = (capacity / nfc::MIFARE_ULTRALIGHT_PAGE_SIZE) + nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE;
 
-  static constexpr std::array<uint8_t, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE> BLANK_DATA = {0x00, 0x00, 0x00, 0x00};
+  std::vector<uint8_t> blank_data = {0x00, 0x00, 0x00, 0x00};
 
   for (int i = nfc::MIFARE_ULTRALIGHT_DATA_START_PAGE; i < pages; i++) {
-    if (this->write_mifare_ultralight_page_(i, BLANK_DATA.data(), BLANK_DATA.size()) != nfc::STATUS_OK) {
+    if (this->write_mifare_ultralight_page_(i, blank_data) != nfc::STATUS_OK) {
       return nfc::STATUS_FAILED;
     }
   }
   return nfc::STATUS_OK;
 }
 
-uint8_t PN7160::write_mifare_ultralight_page_(uint8_t page_num, const uint8_t *write_data, size_t len) {
+uint8_t PN7160::write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data) {
   std::vector<uint8_t> payload = {nfc::MIFARE_CMD_WRITE_ULTRALIGHT, page_num};
-  payload.insert(payload.end(), write_data, write_data + len);
+  payload.insert(payload.end(), write_data.begin(), write_data.end());
 
   nfc::NciMessage rx;
   nfc::NciMessage tx(nfc::NCI_PKT_MT_DATA, payload);

esphome/components/runtime_image/__init__.py

@@ -0,0 +1,191 @@
+from dataclasses import dataclass
+
+import esphome.codegen as cg
+from esphome.components.const import CONF_BYTE_ORDER
+from esphome.components.image import (
+    IMAGE_TYPE,
+    Image_,
+    validate_settings,
+    validate_transparency,
+    validate_type,
+)
+import esphome.config_validation as cv
+from esphome.const import CONF_FORMAT, CONF_ID, CONF_RESIZE, CONF_TYPE
+
+AUTO_LOAD = ["image"]
+CODEOWNERS = ["@guillempages", "@clydebarrow", "@kahrendt"]
+
+CONF_PLACEHOLDER = "placeholder"
+CONF_TRANSPARENCY = "transparency"
+
+runtime_image_ns = cg.esphome_ns.namespace("runtime_image")
+
+# Base decoder classes
+ImageDecoder = runtime_image_ns.class_("ImageDecoder")
+BmpDecoder = runtime_image_ns.class_("BmpDecoder", ImageDecoder)
+JpegDecoder = runtime_image_ns.class_("JpegDecoder", ImageDecoder)
+PngDecoder = runtime_image_ns.class_("PngDecoder", ImageDecoder)
+
+# Runtime image class
+RuntimeImage = runtime_image_ns.class_(
+    "RuntimeImage", cg.esphome_ns.namespace("image").class_("Image")
+)
+
+# Image format enum
+ImageFormat = runtime_image_ns.enum("ImageFormat")
+IMAGE_FORMAT_AUTO = ImageFormat.AUTO
+IMAGE_FORMAT_JPEG = ImageFormat.JPEG
+IMAGE_FORMAT_PNG = ImageFormat.PNG
+IMAGE_FORMAT_BMP = ImageFormat.BMP
+
+# Export enum for decode errors
+DecodeError = runtime_image_ns.enum("DecodeError")
+DECODE_ERROR_INVALID_TYPE = DecodeError.DECODE_ERROR_INVALID_TYPE
+DECODE_ERROR_UNSUPPORTED_FORMAT = DecodeError.DECODE_ERROR_UNSUPPORTED_FORMAT
+DECODE_ERROR_OUT_OF_MEMORY = DecodeError.DECODE_ERROR_OUT_OF_MEMORY
+
+
+class Format:
+    """Base class for image format definitions."""
+
+    def __init__(self, name: str, decoder_class: cg.MockObjClass) -> None:
+        self.name = name
+        self.decoder_class = decoder_class
+
+    def actions(self) -> None:
+        """Add defines and libraries needed for this format."""
+
+
+class BMPFormat(Format):
+    """BMP format decoder configuration."""
+
+    def __init__(self):
+        super().__init__("BMP", BmpDecoder)
+
+    def actions(self) -> None:
+        cg.add_define("USE_RUNTIME_IMAGE_BMP")
+
+
+class JPEGFormat(Format):
+    """JPEG format decoder configuration."""
+
+    def __init__(self):
+        super().__init__("JPEG", JpegDecoder)
+
+    def actions(self) -> None:
+        cg.add_define("USE_RUNTIME_IMAGE_JPEG")
+        cg.add_library("JPEGDEC", None, "https://github.com/bitbank2/JPEGDEC#ca1e0f2")
+
+
+class PNGFormat(Format):
+    """PNG format decoder configuration."""
+
+    def __init__(self):
+        super().__init__("PNG", PngDecoder)
+
+    def actions(self) -> None:
+        cg.add_define("USE_RUNTIME_IMAGE_PNG")
+        cg.add_library("pngle", "1.1.0")
+
+
+# Registry of available formats
+IMAGE_FORMATS = {
+    "BMP": BMPFormat(),
+    "JPEG": JPEGFormat(),
+    "PNG": PNGFormat(),
+    "JPG": JPEGFormat(),  # Alias for JPEG
+}
+
+
+def get_format(format_name: str) -> Format | None:
+    """Get a format instance by name."""
+    return IMAGE_FORMATS.get(format_name.upper())
+
+
+def enable_format(format_name: str) -> Format | None:
+    """Enable a specific image format by adding its defines and libraries."""
+    format_obj = get_format(format_name)
+    if format_obj:
+        format_obj.actions()
+        return format_obj
+    return None
+
+
+# Runtime image configuration schema base - to be extended by components
+def runtime_image_schema(image_class: cg.MockObjClass = RuntimeImage) -> cv.Schema:
+    """Create a runtime image schema with the specified image class."""
+    return cv.Schema(
+        {
+            cv.Required(CONF_ID): cv.declare_id(image_class),
+            cv.Required(CONF_FORMAT): cv.one_of(*IMAGE_FORMATS, upper=True),
+            cv.Optional(CONF_RESIZE): cv.dimensions,
+            cv.Required(CONF_TYPE): validate_type(IMAGE_TYPE),
+            cv.Optional(CONF_BYTE_ORDER): cv.one_of(
+                "BIG_ENDIAN", "LITTLE_ENDIAN", upper=True
+            ),
+            cv.Optional(CONF_TRANSPARENCY, default="OPAQUE"): validate_transparency(),
+            cv.Optional(CONF_PLACEHOLDER): cv.use_id(Image_),
+        }
+    )
+
+
+def validate_runtime_image_settings(config: dict) -> dict:
+    """Apply validate_settings from image component to runtime image config."""
+    return validate_settings(config)
+
+
+@dataclass
+class RuntimeImageSettings:
+    """Processed runtime image configuration parameters."""
+
+    width: int
+    height: int
+    format_enum: cg.MockObj
+    image_type_enum: cg.MockObj
+    transparent: cg.MockObj
+    byte_order_big_endian: bool
+    placeholder: cg.MockObj | None
+
+
+async def process_runtime_image_config(config: dict) -> RuntimeImageSettings:
+    """
+    Helper function to process common runtime image configuration parameters.
+    Handles format enabling and returns all necessary enums and parameters.
+    """
+    from esphome.components.image import get_image_type_enum, get_transparency_enum
+
+    # Get resize dimensions with default (0, 0)
+    width, height = config.get(CONF_RESIZE, (0, 0))
+
+    # Handle format (required for runtime images)
+    format_name = config[CONF_FORMAT]
+    # Enable the format in the runtime_image component
+    enable_format(format_name)
+    # Map format names to enum values (handle JPG as alias for JPEG)
+    if format_name.upper() == "JPG":
+        format_name = "JPEG"
+    format_enum = getattr(ImageFormat, format_name.upper())
+
+    # Get image type enum
+    image_type_enum = get_image_type_enum(config[CONF_TYPE])
+
+    # Get transparency enum
+    transparent = get_transparency_enum(config.get(CONF_TRANSPARENCY, "OPAQUE"))
+
+    # Get byte order (True for big endian, False for little endian)
+    byte_order_big_endian = config.get(CONF_BYTE_ORDER) != "LITTLE_ENDIAN"
+
+    # Get placeholder if specified
+    placeholder = None
+    if placeholder_id := config.get(CONF_PLACEHOLDER):
+        placeholder = await cg.get_variable(placeholder_id)
+
+    return RuntimeImageSettings(
+        width=width,
+        height=height,
+        format_enum=format_enum,
+        image_type_enum=image_type_enum,
+        transparent=transparent,
+        byte_order_big_endian=byte_order_big_endian,
+        placeholder=placeholder,
+    )

esphome/components/runtime_image/bmp_decoder.cpp

@@ -1,15 +1,14 @@
-#include "bmp_image.h"
+#include "bmp_decoder.h"
 
-#ifdef USE_ONLINE_IMAGE_BMP_SUPPORT
+#ifdef USE_RUNTIME_IMAGE_BMP
 
 #include "esphome/components/display/display.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
-static const char *const TAG = "online_image.bmp";
+static const char *const TAG = "image_decoder.bmp";
 
 int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
   size_t index = 0;
@@ -30,7 +29,11 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
       return DECODE_ERROR_INVALID_TYPE;
     }
 
-    this->download_size_ = encode_uint32(buffer[5], buffer[4], buffer[3], buffer[2]);
+    // BMP file contains its own size in the header
+    size_t file_size = encode_uint32(buffer[5], buffer[4], buffer[3], buffer[2]);
+    if (this->expected_size_ == 0) {
+      this->expected_size_ = file_size;  // Use file header size if not provided
+    }
     this->data_offset_ = encode_uint32(buffer[13], buffer[12], buffer[11], buffer[10]);
 
     this->current_index_ = 14;
@@ -90,8 +93,8 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
       while (index < size) {
         uint8_t current_byte = buffer[index];
         for (uint8_t i = 0; i < 8; i++) {
-          size_t x = (this->paint_index_ % this->width_) + i;
-          size_t y = (this->height_ - 1) - (this->paint_index_ / this->width_);
+          size_t x = (this->paint_index_ % static_cast<size_t>(this->width_)) + i;
+          size_t y = static_cast<size_t>(this->height_ - 1) - (this->paint_index_ / static_cast<size_t>(this->width_));
           Color c = (current_byte & (1 << (7 - i))) ? display::COLOR_ON : display::COLOR_OFF;
           this->draw(x, y, 1, 1, c);
         }
@@ -110,8 +113,8 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
         uint8_t b = buffer[index];
         uint8_t g = buffer[index + 1];
         uint8_t r = buffer[index + 2];
-        size_t x = this->paint_index_ % this->width_;
-        size_t y = (this->height_ - 1) - (this->paint_index_ / this->width_);
+        size_t x = this->paint_index_ % static_cast<size_t>(this->width_);
+        size_t y = static_cast<size_t>(this->height_ - 1) - (this->paint_index_ / static_cast<size_t>(this->width_));
         Color c = Color(r, g, b);
         this->draw(x, y, 1, 1, c);
         this->paint_index_++;
@@ -133,7 +136,6 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
   return size;
 };
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_BMP_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_BMP

esphome/components/runtime_image/bmp_decoder.h

@@ -1,27 +1,32 @@
 #pragma once
 
 #include "esphome/core/defines.h"
-#ifdef USE_ONLINE_IMAGE_BMP_SUPPORT
+#ifdef USE_RUNTIME_IMAGE_BMP
 
 #include "image_decoder.h"
+#include "runtime_image.h"
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
 /**
- * @brief Image decoder specialization for PNG images.
+ * @brief Image decoder specialization for BMP images.
  */
 class BmpDecoder : public ImageDecoder {
  public:
   /**
    * @brief Construct a new BMP Decoder object.
    *
-   * @param display The image to decode the stream into.
+   * @param image The RuntimeImage to decode the stream into.
    */
-  BmpDecoder(OnlineImage *image) : ImageDecoder(image) {}
+  BmpDecoder(RuntimeImage *image) : ImageDecoder(image) {}
 
   int HOT decode(uint8_t *buffer, size_t size) override;
 
+  bool is_finished() const override {
+    // BMP is finished when we've decoded all pixel data
+    return this->paint_index_ >= static_cast<size_t>(this->width_ * this->height_);
+  }
+
  protected:
   size_t current_index_{0};
   size_t paint_index_{0};
@@ -36,7 +41,6 @@ class BmpDecoder : public ImageDecoder {
   uint8_t padding_bytes_{0};
 };
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_BMP_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_BMP

esphome/components/runtime_image/image_decoder.cpp

@@ -0,0 +1,28 @@
+#include "image_decoder.h"
+#include "runtime_image.h"
+#include "esphome/core/log.h"
+#include <algorithm>
+#include <cmath>
+
+namespace esphome::runtime_image {
+
+static const char *const TAG = "image_decoder";
+
+bool ImageDecoder::set_size(int width, int height) {
+  bool success = this->image_->resize(width, height) > 0;
+  this->x_scale_ = static_cast<double>(this->image_->get_buffer_width()) / width;
+  this->y_scale_ = static_cast<double>(this->image_->get_buffer_height()) / height;
+  return success;
+}
+
+void ImageDecoder::draw(int x, int y, int w, int h, const Color &color) {
+  auto width = std::min(this->image_->get_buffer_width(), static_cast<int>(std::ceil((x + w) * this->x_scale_)));
+  auto height = std::min(this->image_->get_buffer_height(), static_cast<int>(std::ceil((y + h) * this->y_scale_)));
+  for (int i = x * this->x_scale_; i < width; i++) {
+    for (int j = y * this->y_scale_; j < height; j++) {
+      this->image_->draw_pixel(i, j, color);
+    }
+  }
+}
+
+}  // namespace esphome::runtime_image

esphome/components/runtime_image/image_decoder.h

@@ -1,8 +1,7 @@
 #pragma once
 #include "esphome/core/color.h"
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
 enum DecodeError : int {
   DECODE_ERROR_INVALID_TYPE = -1,
@@ -10,7 +9,7 @@ enum DecodeError : int {
   DECODE_ERROR_OUT_OF_MEMORY = -3,
 };
 
-class OnlineImage;
+class RuntimeImage;
 
 /**
  * @brief Class to abstract decoding different image formats.
@@ -20,19 +19,19 @@ class ImageDecoder {
   /**
    * @brief Construct a new Image Decoder object
    *
-   * @param image The image to decode the stream into.
+   * @param image The RuntimeImage to decode the stream into.
    */
-  ImageDecoder(OnlineImage *image) : image_(image) {}
+  ImageDecoder(RuntimeImage *image) : image_(image) {}
   virtual ~ImageDecoder() = default;
 
   /**
    * @brief Initialize the decoder.
    *
-   * @param download_size The total number of bytes that need to be downloaded for the image.
+   * @param expected_size Hint about the expected data size (0 if unknown).
    * @return int          Returns 0 on success, a {@see DecodeError} value in case of an error.
    */
-  virtual int prepare(size_t download_size) {
-    this->download_size_ = download_size;
+  virtual int prepare(size_t expected_size) {
+    this->expected_size_ = expected_size;
     return 0;
   }
 
@@ -73,49 +72,26 @@ class ImageDecoder {
    */
   void draw(int x, int y, int w, int h, const Color &color);
 
-  bool is_finished() const { return this->decoded_bytes_ == this->download_size_; }
+  /**
+   * @brief Check if the decoder has finished processing.
+   *
+   * This should be overridden by decoders that can detect completion
+   * based on format-specific markers rather than byte counts.
+   */
+  virtual bool is_finished() const {
+    if (this->expected_size_ > 0) {
+      return this->decoded_bytes_ >= this->expected_size_;
+    }
+    // If size is unknown, derived classes should override this
+    return false;
+  }
 
  protected:
-  OnlineImage *image_;
-  // Initializing to 1, to ensure it is distinguishable from initial "decoded_bytes_".
-  // Will be overwritten anyway once the download size is known.
-  size_t download_size_ = 1;
-  size_t decoded_bytes_ = 0;
+  RuntimeImage *image_;
+  size_t expected_size_ = 0;  // Expected data size (0 if unknown)
+  size_t decoded_bytes_ = 0;  // Bytes processed so far
   double x_scale_ = 1.0;
   double y_scale_ = 1.0;
 };
 
-class DownloadBuffer {
- public:
-  DownloadBuffer(size_t size);
-
-  virtual ~DownloadBuffer() { this->allocator_.deallocate(this->buffer_, this->size_); }
-
-  uint8_t *data(size_t offset = 0);
-
-  uint8_t *append() { return this->data(this->unread_); }
-
-  size_t unread() const { return this->unread_; }
-  size_t size() const { return this->size_; }
-  size_t free_capacity() const { return this->size_ - this->unread_; }
-
-  size_t read(size_t len);
-  size_t write(size_t len) {
-    this->unread_ += len;
-    return this->unread_;
-  }
-
-  void reset() { this->unread_ = 0; }
-
-  size_t resize(size_t size);
-
- protected:
-  RAMAllocator<uint8_t> allocator_{};
-  uint8_t *buffer_;
-  size_t size_;
-  /** Total number of downloaded bytes not yet read. */
-  size_t unread_;
-};
-
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image

esphome/components/runtime_image/jpeg_decoder.cpp

@@ -1,16 +1,19 @@
-#include "jpeg_image.h"
-#ifdef USE_ONLINE_IMAGE_JPEG_SUPPORT
+#include "jpeg_decoder.h"
+#ifdef USE_RUNTIME_IMAGE_JPEG
 
 #include "esphome/components/display/display_buffer.h"
 #include "esphome/core/application.h"
+#include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
-#include "online_image.h"
-static const char *const TAG = "online_image.jpeg";
+#ifdef USE_ESP_IDF
+#include "esp_task_wdt.h"
+#endif
 
-namespace esphome {
-namespace online_image {
+static const char *const TAG = "image_decoder.jpeg";
+
+namespace esphome::runtime_image {
 
 /**
  * @brief Callback method that will be called by the JPEGDEC engine when a chunk
@@ -22,8 +25,14 @@ static int draw_callback(JPEGDRAW *jpeg) {
   ImageDecoder *decoder = (ImageDecoder *) jpeg->pUser;
 
   // Some very big images take too long to decode, so feed the watchdog on each callback
-  // to avoid crashing.
-  App.feed_wdt();
+  // to avoid crashing if the executing task has a watchdog enabled.
+#ifdef USE_ESP_IDF
+  if (esp_task_wdt_status(nullptr) == ESP_OK) {
+#endif
+    App.feed_wdt();
+#ifdef USE_ESP_IDF
+  }
+#endif
   size_t position = 0;
   size_t height = static_cast<size_t>(jpeg->iHeight);
   size_t width = static_cast<size_t>(jpeg->iWidth);
@@ -43,22 +52,23 @@ static int draw_callback(JPEGDRAW *jpeg) {
   return 1;
 }
 
-int JpegDecoder::prepare(size_t download_size) {
-  ImageDecoder::prepare(download_size);
-  auto size = this->image_->resize_download_buffer(download_size);
-  if (size < download_size) {
-    ESP_LOGE(TAG, "Download buffer resize failed!");
-    return DECODE_ERROR_OUT_OF_MEMORY;
-  }
+int JpegDecoder::prepare(size_t expected_size) {
+  ImageDecoder::prepare(expected_size);
+  // JPEG decoder needs complete data before decoding
   return 0;
 }
 
 int HOT JpegDecoder::decode(uint8_t *buffer, size_t size) {
-  if (size < this->download_size_) {
-    ESP_LOGV(TAG, "Download not complete. Size: %d/%d", size, this->download_size_);
+  // JPEG decoder requires complete data
+  // If we know the expected size, wait for it
+  if (this->expected_size_ > 0 && size < this->expected_size_) {
+    ESP_LOGV(TAG, "Download not complete. Size: %zu/%zu", size, this->expected_size_);
     return 0;
   }
 
+  // If size unknown, try to decode and see if it's valid
+  // The JPEGDEC library will fail gracefully if data is incomplete
+
   if (!this->jpeg_.openRAM(buffer, size, draw_callback)) {
     ESP_LOGE(TAG, "Could not open image for decoding: %d", this->jpeg_.getLastError());
     return DECODE_ERROR_INVALID_TYPE;
@@ -88,7 +98,6 @@ int HOT JpegDecoder::decode(uint8_t *buffer, size_t size) {
   return size;
 }
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_JPEG_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_JPEG

esphome/components/runtime_image/jpeg_decoder.h

@@ -1,12 +1,12 @@
 #pragma once
 
 #include "image_decoder.h"
+#include "runtime_image.h"
 #include "esphome/core/defines.h"
-#ifdef USE_ONLINE_IMAGE_JPEG_SUPPORT
+#ifdef USE_RUNTIME_IMAGE_JPEG
 #include <JPEGDEC.h>
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
 /**
  * @brief Image decoder specialization for JPEG images.
@@ -16,19 +16,18 @@ class JpegDecoder : public ImageDecoder {
   /**
    * @brief Construct a new JPEG Decoder object.
    *
-   * @param display The image to decode the stream into.
+   * @param image The RuntimeImage to decode the stream into.
    */
-  JpegDecoder(OnlineImage *image) : ImageDecoder(image) {}
+  JpegDecoder(RuntimeImage *image) : ImageDecoder(image) {}
   ~JpegDecoder() override {}
 
-  int prepare(size_t download_size) override;
+  int prepare(size_t expected_size) override;
   int HOT decode(uint8_t *buffer, size_t size) override;
 
  protected:
   JPEGDEC jpeg_{};
 };
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_JPEG_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_JPEG

esphome/components/runtime_image/png_decoder.cpp

@@ -1,15 +1,14 @@
-#include "png_image.h"
-#ifdef USE_ONLINE_IMAGE_PNG_SUPPORT
+#include "png_decoder.h"
+#ifdef USE_RUNTIME_IMAGE_PNG
 
 #include "esphome/components/display/display_buffer.h"
 #include "esphome/core/application.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
-static const char *const TAG = "online_image.png";
+static const char *const TAG = "image_decoder.png";
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
 /**
  * @brief Callback method that will be called by the PNGLE engine when the basic
@@ -49,7 +48,7 @@ static void draw_callback(pngle_t *pngle, uint32_t x, uint32_t y, uint32_t w, ui
   }
 }
 
-PngDecoder::PngDecoder(OnlineImage *image) : ImageDecoder(image) {
+PngDecoder::PngDecoder(RuntimeImage *image) : ImageDecoder(image) {
   {
     pngle_t *pngle = this->allocator_.allocate(1, PNGLE_T_SIZE);
     if (!pngle) {
@@ -69,8 +68,8 @@ PngDecoder::~PngDecoder() {
   }
 }
 
-int PngDecoder::prepare(size_t download_size) {
-  ImageDecoder::prepare(download_size);
+int PngDecoder::prepare(size_t expected_size) {
+  ImageDecoder::prepare(expected_size);
   if (!this->pngle_) {
     ESP_LOGE(TAG, "PNG decoder engine not initialized!");
     return DECODE_ERROR_OUT_OF_MEMORY;
@@ -86,8 +85,9 @@ int HOT PngDecoder::decode(uint8_t *buffer, size_t size) {
     ESP_LOGE(TAG, "PNG decoder engine not initialized!");
     return DECODE_ERROR_OUT_OF_MEMORY;
   }
-  if (size < 256 && size < this->download_size_ - this->decoded_bytes_) {
-    ESP_LOGD(TAG, "Waiting for data");
+  // PNG can be decoded progressively, but wait for a reasonable chunk
+  if (size < 256 && this->expected_size_ > 0 && size < this->expected_size_ - this->decoded_bytes_) {
+    ESP_LOGD(TAG, "Waiting for more data");
     return 0;
   }
   auto fed = pngle_feed(this->pngle_, buffer, size);
@@ -99,7 +99,6 @@ int HOT PngDecoder::decode(uint8_t *buffer, size_t size) {
   return fed;
 }
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_PNG_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_PNG

esphome/components/runtime_image/png_decoder.h

@@ -3,11 +3,11 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "image_decoder.h"
-#ifdef USE_ONLINE_IMAGE_PNG_SUPPORT
+#include "runtime_image.h"
+#ifdef USE_RUNTIME_IMAGE_PNG
 #include <pngle.h>
 
-namespace esphome {
-namespace online_image {
+namespace esphome::runtime_image {
 
 /**
  * @brief Image decoder specialization for PNG images.
@@ -17,12 +17,12 @@ class PngDecoder : public ImageDecoder {
   /**
    * @brief Construct a new PNG Decoder object.
    *
-   * @param display The image to decode the stream into.
+   * @param image The RuntimeImage to decode the stream into.
    */
-  PngDecoder(OnlineImage *image);
+  PngDecoder(RuntimeImage *image);
   ~PngDecoder() override;
 
-  int prepare(size_t download_size) override;
+  int prepare(size_t expected_size) override;
   int HOT decode(uint8_t *buffer, size_t size) override;
 
   void increment_pixels_decoded(uint32_t count) { this->pixels_decoded_ += count; }
@@ -30,11 +30,10 @@ class PngDecoder : public ImageDecoder {
 
  protected:
   RAMAllocator<pngle_t> allocator_;
-  pngle_t *pngle_;
+  pngle_t *pngle_{nullptr};
   uint32_t pixels_decoded_{0};
 };
 
-}  // namespace online_image
-}  // namespace esphome
+}  // namespace esphome::runtime_image
 
-#endif  // USE_ONLINE_IMAGE_PNG_SUPPORT
+#endif  // USE_RUNTIME_IMAGE_PNG

esphome/components/runtime_image/runtime_image.cpp

@@ -0,0 +1,300 @@
+#include "runtime_image.h"
+#include "image_decoder.h"
+#include "esphome/core/log.h"
+#include "esphome/core/helpers.h"
+#include <cstring>
+
+#ifdef USE_RUNTIME_IMAGE_BMP
+#include "bmp_decoder.h"
+#endif
+#ifdef USE_RUNTIME_IMAGE_JPEG
+#include "jpeg_decoder.h"
+#endif
+#ifdef USE_RUNTIME_IMAGE_PNG
+#include "png_decoder.h"
+#endif
+
+namespace esphome::runtime_image {
+
+static const char *const TAG = "runtime_image";
+
+inline bool is_color_on(const Color &color) {
+  // This produces the most accurate monochrome conversion, but is slightly slower.
+  //  return (0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b) > 127;
+
+  // Approximation using fast integer computations; produces acceptable results
+  // Equivalent to 0.25 * R + 0.5 * G + 0.25 * B
+  return ((color.r >> 2) + (color.g >> 1) + (color.b >> 2)) & 0x80;
+}
+
+RuntimeImage::RuntimeImage(ImageFormat format, image::ImageType type, image::Transparency transparency,
+                           image::Image *placeholder, bool is_big_endian, int fixed_width, int fixed_height)
+    : Image(nullptr, 0, 0, type, transparency),
+      format_(format),
+      fixed_width_(fixed_width),
+      fixed_height_(fixed_height),
+      placeholder_(placeholder),
+      is_big_endian_(is_big_endian) {}
+
+RuntimeImage::~RuntimeImage() { this->release(); }
+
+int RuntimeImage::resize(int width, int height) {
+  // Use fixed dimensions if specified (0 means auto-resize)
+  int target_width = this->fixed_width_ ? this->fixed_width_ : width;
+  int target_height = this->fixed_height_ ? this->fixed_height_ : height;
+
+  size_t result = this->resize_buffer_(target_width, target_height);
+  if (result > 0 && this->progressive_display_) {
+    // Update display dimensions for progressive display
+    this->width_ = this->buffer_width_;
+    this->height_ = this->buffer_height_;
+    this->data_start_ = this->buffer_;
+  }
+  return result;
+}
+
+void RuntimeImage::draw_pixel(int x, int y, const Color &color) {
+  if (!this->buffer_) {
+    ESP_LOGE(TAG, "Buffer not allocated!");
+    return;
+  }
+  if (x < 0 || y < 0 || x >= this->buffer_width_ || y >= this->buffer_height_) {
+    ESP_LOGE(TAG, "Tried to paint a pixel (%d,%d) outside the image!", x, y);
+    return;
+  }
+
+  switch (this->type_) {
+    case image::IMAGE_TYPE_BINARY: {
+      const uint32_t width_8 = ((this->buffer_width_ + 7u) / 8u) * 8u;
+      uint32_t pos = x + y * width_8;
+      auto bitno = 0x80 >> (pos % 8u);
+      pos /= 8u;
+      auto on = is_color_on(color);
+      if (this->has_transparency() && color.w < 0x80)
+        on = false;
+      if (on) {
+        this->buffer_[pos] |= bitno;
+      } else {
+        this->buffer_[pos] &= ~bitno;
+      }
+      break;
+    }
+    case image::IMAGE_TYPE_GRAYSCALE: {
+      uint32_t pos = this->get_position_(x, y);
+      auto gray = static_cast<uint8_t>(0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b);
+      if (this->transparency_ == image::TRANSPARENCY_CHROMA_KEY) {
+        if (gray == 1) {
+          gray = 0;
+        }
+        if (color.w < 0x80) {
+          gray = 1;
+        }
+      } else if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
+        if (color.w != 0xFF)
+          gray = color.w;
+      }
+      this->buffer_[pos] = gray;
+      break;
+    }
+    case image::IMAGE_TYPE_RGB565: {
+      uint32_t pos = this->get_position_(x, y);
+      Color mapped_color = color;
+      this->map_chroma_key(mapped_color);
+      uint16_t rgb565 = display::ColorUtil::color_to_565(mapped_color);
+      if (this->is_big_endian_) {
+        this->buffer_[pos + 0] = static_cast<uint8_t>((rgb565 >> 8) & 0xFF);
+        this->buffer_[pos + 1] = static_cast<uint8_t>(rgb565 & 0xFF);
+      } else {
+        this->buffer_[pos + 0] = static_cast<uint8_t>(rgb565 & 0xFF);
+        this->buffer_[pos + 1] = static_cast<uint8_t>((rgb565 >> 8) & 0xFF);
+      }
+      if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
+        this->buffer_[pos + 2] = color.w;
+      }
+      break;
+    }
+    case image::IMAGE_TYPE_RGB: {
+      uint32_t pos = this->get_position_(x, y);
+      Color mapped_color = color;
+      this->map_chroma_key(mapped_color);
+      this->buffer_[pos + 0] = mapped_color.r;
+      this->buffer_[pos + 1] = mapped_color.g;
+      this->buffer_[pos + 2] = mapped_color.b;
+      if (this->transparency_ == image::TRANSPARENCY_ALPHA_CHANNEL) {
+        this->buffer_[pos + 3] = color.w;
+      }
+      break;
+    }
+  }
+}
+
+void RuntimeImage::map_chroma_key(Color &color) {
+  if (this->transparency_ == image::TRANSPARENCY_CHROMA_KEY) {
+    if (color.g == 1 && color.r == 0 && color.b == 0) {
+      color.g = 0;
+    }
+    if (color.w < 0x80) {
+      color.r = 0;
+      color.g = this->type_ == image::IMAGE_TYPE_RGB565 ? 4 : 1;
+      color.b = 0;
+    }
+  }
+}
+
+void RuntimeImage::draw(int x, int y, display::Display *display, Color color_on, Color color_off) {
+  if (this->data_start_) {
+    // If we have a complete image, use the base class draw method
+    Image::draw(x, y, display, color_on, color_off);
+  } else if (this->placeholder_) {
+    // Show placeholder while the runtime image is not available
+    this->placeholder_->draw(x, y, display, color_on, color_off);
+  }
+  // If no image is loaded and no placeholder, nothing to draw
+}
+
+bool RuntimeImage::begin_decode(size_t expected_size) {
+  if (this->decoder_) {
+    ESP_LOGW(TAG, "Decoding already in progress");
+    return false;
+  }
+
+  this->decoder_ = this->create_decoder_();
+  if (!this->decoder_) {
+    ESP_LOGE(TAG, "Failed to create decoder for format %d", this->format_);
+    return false;
+  }
+
+  this->total_size_ = expected_size;
+  this->decoded_bytes_ = 0;
+
+  // Initialize decoder
+  int result = this->decoder_->prepare(expected_size);
+  if (result < 0) {
+    ESP_LOGE(TAG, "Failed to prepare decoder: %d", result);
+    this->decoder_ = nullptr;
+    return false;
+  }
+
+  return true;
+}
+
+int RuntimeImage::feed_data(uint8_t *data, size_t len) {
+  if (!this->decoder_) {
+    ESP_LOGE(TAG, "No decoder initialized");
+    return -1;
+  }
+
+  int consumed = this->decoder_->decode(data, len);
+  if (consumed > 0) {
+    this->decoded_bytes_ += consumed;
+  }
+
+  return consumed;
+}
+
+bool RuntimeImage::end_decode() {
+  if (!this->decoder_) {
+    return false;
+  }
+
+  // Finalize the image for display
+  if (!this->progressive_display_) {
+    // Only now make the image visible
+    this->width_ = this->buffer_width_;
+    this->height_ = this->buffer_height_;
+    this->data_start_ = this->buffer_;
+  }
+
+  // Clean up decoder
+  this->decoder_ = nullptr;
+
+  ESP_LOGD(TAG, "Decoding complete: %dx%d, %zu bytes", this->width_, this->height_, this->decoded_bytes_);
+  return true;
+}
+
+bool RuntimeImage::is_decode_finished() const {
+  if (!this->decoder_) {
+    return false;
+  }
+  return this->decoder_->is_finished();
+}
+
+void RuntimeImage::release() {
+  this->release_buffer_();
+  // Reset decoder separately — release() can be called from within the decoder
+  // (via set_size -> resize -> resize_buffer_), so we must not destroy the decoder here.
+  // The decoder lifecycle is managed by begin_decode()/end_decode().
+  this->decoder_ = nullptr;
+}
+
+void RuntimeImage::release_buffer_() {
+  if (this->buffer_) {
+    ESP_LOGV(TAG, "Releasing buffer of size %zu", this->get_buffer_size_(this->buffer_width_, this->buffer_height_));
+    this->allocator_.deallocate(this->buffer_, this->get_buffer_size_(this->buffer_width_, this->buffer_height_));
+    this->buffer_ = nullptr;
+    this->data_start_ = nullptr;
+    this->width_ = 0;
+    this->height_ = 0;
+    this->buffer_width_ = 0;
+    this->buffer_height_ = 0;
+  }
+}
+
+size_t RuntimeImage::resize_buffer_(int width, int height) {
+  size_t new_size = this->get_buffer_size_(width, height);
+
+  if (this->buffer_ && this->buffer_width_ == width && this->buffer_height_ == height) {
+    // Buffer already allocated with correct size
+    return new_size;
+  }
+
+  // Release old buffer if dimensions changed
+  if (this->buffer_) {
+    this->release_buffer_();
+  }
+
+  ESP_LOGD(TAG, "Allocating buffer: %dx%d, %zu bytes", width, height, new_size);
+  this->buffer_ = this->allocator_.allocate(new_size);
+
+  if (!this->buffer_) {
+    ESP_LOGE(TAG, "Failed to allocate %zu bytes. Largest free block: %zu", new_size,
+             this->allocator_.get_max_free_block_size());
+    return 0;
+  }
+
+  // Clear buffer
+  memset(this->buffer_, 0, new_size);
+
+  this->buffer_width_ = width;
+  this->buffer_height_ = height;
+
+  return new_size;
+}
+
+size_t RuntimeImage::get_buffer_size_(int width, int height) const {
+  return (this->get_bpp() * width + 7u) / 8u * height;
+}
+
+int RuntimeImage::get_position_(int x, int y) const { return (x + y * this->buffer_width_) * this->get_bpp() / 8; }
+
+std::unique_ptr<ImageDecoder> RuntimeImage::create_decoder_() {
+  switch (this->format_) {
+#ifdef USE_RUNTIME_IMAGE_BMP
+    case BMP:
+      return make_unique<BmpDecoder>(this);
+#endif
+#ifdef USE_RUNTIME_IMAGE_JPEG
+    case JPEG:
+      return make_unique<JpegDecoder>(this);
+#endif
+#ifdef USE_RUNTIME_IMAGE_PNG
+    case PNG:
+      return make_unique<PngDecoder>(this);
+#endif
+    default:
+      ESP_LOGE(TAG, "Unsupported image format: %d", this->format_);
+      return nullptr;
+  }
+}
+
+}  // namespace esphome::runtime_image

esphome/components/runtime_image/runtime_image.h

@@ -0,0 +1,214 @@
+#pragma once
+
+#include "esphome/components/image/image.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome::runtime_image {
+
+// Forward declaration
+class ImageDecoder;
+
+/**
+ * @brief Image format types that can be decoded dynamically.
+ */
+enum ImageFormat {
+  /** Automatically detect from data. Not implemented yet. */
+  AUTO,
+  /** JPEG format. */
+  JPEG,
+  /** PNG format. */
+  PNG,
+  /** BMP format. */
+  BMP,
+};
+
+/**
+ * @brief A dynamic image that can be loaded and decoded at runtime.
+ *
+ * This class provides dynamic buffer allocation and management for images
+ * that are decoded at runtime, as opposed to static images compiled into
+ * the firmware. It serves as a base class for components that need to
+ * load images dynamically from various sources.
+ */
+class RuntimeImage : public image::Image {
+ public:
+  /**
+   * @brief Construct a new RuntimeImage object.
+   *
+   * @param format The image format to decode.
+   * @param type The pixel format for the image.
+   * @param transparency The transparency type for the image.
+   * @param placeholder Optional placeholder image to show while loading.
+   * @param is_big_endian Whether the image is stored in big-endian format.
+   * @param fixed_width Fixed width for the image (0 for auto-resize).
+   * @param fixed_height Fixed height for the image (0 for auto-resize).
+   */
+  RuntimeImage(ImageFormat format, image::ImageType type, image::Transparency transparency,
+               image::Image *placeholder = nullptr, bool is_big_endian = false, int fixed_width = 0,
+               int fixed_height = 0);
+
+  ~RuntimeImage();
+
+  // Decoder interface methods
+  /**
+   * @brief Resize the image buffer to the requested dimensions.
+   *
+   * The buffer will be allocated if not existing.
+   * If fixed dimensions have been specified in the constructor, the buffer will be created
+   * with those dimensions and not resized, even on request.
+   * Otherwise, the old buffer will be deallocated and a new buffer with the requested
+   * dimensions allocated.
+   *
+   * @param width Requested width (ignored if fixed_width_ is set)
+   * @param height Requested height (ignored if fixed_height_ is set)
+   * @return Size of the allocated buffer in bytes, or 0 if allocation failed.
+   */
+  int resize(int width, int height);
+  void draw_pixel(int x, int y, const Color &color);
+  void map_chroma_key(Color &color);
+  int get_buffer_width() const { return this->buffer_width_; }
+  int get_buffer_height() const { return this->buffer_height_; }
+
+  // Image drawing interface
+  void draw(int x, int y, display::Display *display, Color color_on, Color color_off) override;
+
+  /**
+   * @brief Begin decoding an image.
+   *
+   * @param expected_size Optional hint about the expected data size.
+   * @return true if decoder was successfully initialized.
+   */
+  bool begin_decode(size_t expected_size = 0);
+
+  /**
+   * @brief Feed data to the decoder.
+   *
+   * @param data Pointer to the data buffer.
+   * @param len Length of data to process.
+   * @return Number of bytes consumed by the decoder.
+   */
+  int feed_data(uint8_t *data, size_t len);
+
+  /**
+   * @brief Complete the decoding process.
+   *
+   * @return true if decoding completed successfully.
+   */
+  bool end_decode();
+
+  /**
+   * @brief Check if decoding is currently in progress.
+   */
+  bool is_decoding() const { return this->decoder_ != nullptr; }
+
+  /**
+   * @brief Check if the decoder has finished processing all data.
+   *
+   * This delegates to the decoder's format-specific completion check,
+   * which handles both known-size and chunked transfer cases.
+   */
+  bool is_decode_finished() const;
+
+  /**
+   * @brief Check if an image is currently loaded.
+   */
+  bool is_loaded() const { return this->buffer_ != nullptr; }
+
+  /**
+   * @brief Get the image format.
+   */
+  ImageFormat get_format() const { return this->format_; }
+
+  /**
+   * @brief Release the image buffer and free memory.
+   */
+  void release();
+
+  /**
+   * @brief Set whether to allow progressive display during decode.
+   *
+   * When enabled, the image can be displayed even while still decoding.
+   * When disabled, the image is only displayed after decoding completes.
+   */
+  void set_progressive_display(bool progressive) { this->progressive_display_ = progressive; }
+
+ protected:
+  /**
+   * @brief Resize the image buffer to the requested dimensions.
+   *
+   * @param width New width in pixels.
+   * @param height New height in pixels.
+   * @return Size of the allocated buffer, or 0 on failure.
+   */
+  size_t resize_buffer_(int width, int height);
+
+  /**
+   * @brief Release only the image buffer without resetting the decoder.
+   *
+   * This is safe to call from within the decoder (e.g., during resize).
+   */
+  void release_buffer_();
+
+  /**
+   * @brief Get the buffer size in bytes for given dimensions.
+   */
+  size_t get_buffer_size_(int width, int height) const;
+
+  /**
+   * @brief Get the position in the buffer for a pixel.
+   */
+  int get_position_(int x, int y) const;
+
+  /**
+   * @brief Create decoder instance for the image's format.
+   */
+  std::unique_ptr<ImageDecoder> create_decoder_();
+
+  // Memory management
+  RAMAllocator<uint8_t> allocator_{};
+  uint8_t *buffer_{nullptr};
+
+  // Decoder management
+  std::unique_ptr<ImageDecoder> decoder_{nullptr};
+  /** The image format this RuntimeImage is configured to decode. */
+  const ImageFormat format_;
+
+  /**
+   * Actual width of the current image.
+   * This needs to be separate from "Image::get_width()" because the latter
+   * must return 0 until the image has been decoded (to avoid showing partially
+   * decoded images). When progressive_display_ is enabled, Image dimensions
+   * are updated during decoding to allow rendering in progress.
+   */
+  int buffer_width_{0};
+  /**
+   * Actual height of the current image.
+   * This needs to be separate from "Image::get_height()" because the latter
+   * must return 0 until the image has been decoded (to avoid showing partially
+   * decoded images). When progressive_display_ is enabled, Image dimensions
+   * are updated during decoding to allow rendering in progress.
+   */
+  int buffer_height_{0};
+
+  // Decoding state
+  size_t total_size_{0};
+  size_t decoded_bytes_{0};
+
+  /** Fixed width requested on configuration, or 0 if not specified. */
+  const int fixed_width_{0};
+  /** Fixed height requested on configuration, or 0 if not specified. */
+  const int fixed_height_{0};
+
+  /** Placeholder image to show when the runtime image is not available. */
+  image::Image *placeholder_{nullptr};
+
+  // Configuration
+  bool progressive_display_{false};
+  /**
+   * Whether the image is stored in big-endian format.
+   * This is used to determine how to store 16 bit colors in the buffer.
+   */
+  bool is_big_endian_{false};
+};
+
+}  // namespace esphome::runtime_image

esphome/components/select/select.h

@@ -78,21 +78,23 @@ class Select : public EntityBase {
 
   void add_on_state_callback(std::function<void(size_t)> &&callback);
 
-  /** Set the value of the select by index, this is an optional virtual method.
-   *
-   * This method is called by the SelectCall when the index is already known.
-   * Default implementation converts to string and calls control().
-   * Override this to work directly with indices and avoid string conversions.
-   *
-   * @param index The index as validated by the SelectCall.
-   */
-  virtual void control(size_t index) { this->control(this->option_at(index)); }
-
  protected:
   friend class SelectCall;
 
   size_t active_index_{0};
 
+  /** Set the value of the select by index, this is an optional virtual method.
+   *
+   * IMPORTANT: At least ONE of the two control() methods must be overridden by derived classes.
+   * Overriding this index-based version is PREFERRED as it avoids string conversions.
+   *
+   * This method is called by the SelectCall when the index is already known.
+   * Default implementation converts to string and calls control(const std::string&).
+   *
+   * @param index The index as validated by the SelectCall.
+   */
+  virtual void control(size_t index) { this->control(this->option_at(index)); }
+
   /** Set the value of the select, this is a virtual method that each select integration can implement.
    *
    * IMPORTANT: At least ONE of the two control() methods must be overridden by derived classes.

esphome/components/speed/fan/__init__.py

@@ -25,7 +25,7 @@ CONFIG_SCHEMA = (
             cv.Optional(CONF_SPEED): cv.invalid(
                 "Configuring individual speeds is deprecated."
             ),
-            cv.Optional(CONF_SPEED_COUNT, default=100): cv.int_range(min=1, max=255),
+            cv.Optional(CONF_SPEED_COUNT, default=100): cv.int_range(min=1),
             cv.Optional(CONF_PRESET_MODES): validate_preset_modes,
         }
     )

esphome/components/speed/fan/speed_fan.h

@@ -10,7 +10,7 @@ namespace speed {
 
 class SpeedFan : public Component, public fan::Fan {
  public:
-  SpeedFan(uint8_t speed_count) : speed_count_(speed_count) {}
+  SpeedFan(int speed_count) : speed_count_(speed_count) {}
   void setup() override;
   void dump_config() override;
   void set_output(output::FloatOutput *output) { this->output_ = output; }
@@ -26,7 +26,7 @@ class SpeedFan : public Component, public fan::Fan {
   output::FloatOutput *output_;
   output::BinaryOutput *oscillating_{nullptr};
   output::BinaryOutput *direction_{nullptr};
-  uint8_t speed_count_{};
+  int speed_count_{};
   fan::FanTraits traits_;
   std::vector<const char *> preset_modes_{};
 };

esphome/components/template/fan/__init__.py

@@ -19,7 +19,7 @@ CONFIG_SCHEMA = (
         {
             cv.Optional(CONF_HAS_DIRECTION, default=False): cv.boolean,
             cv.Optional(CONF_HAS_OSCILLATING, default=False): cv.boolean,
-            cv.Optional(CONF_SPEED_COUNT): cv.int_range(min=1, max=255),
+            cv.Optional(CONF_SPEED_COUNT): cv.int_range(min=1),
             cv.Optional(CONF_PRESET_MODES): validate_preset_modes,
         }
     )

esphome/components/template/fan/template_fan.h

@@ -12,7 +12,7 @@ class TemplateFan final : public Component, public fan::Fan {
   void dump_config() override;
   void set_has_direction(bool has_direction) { this->has_direction_ = has_direction; }
   void set_has_oscillating(bool has_oscillating) { this->has_oscillating_ = has_oscillating; }
-  void set_speed_count(uint8_t count) { this->speed_count_ = count; }
+  void set_speed_count(int count) { this->speed_count_ = count; }
   void set_preset_modes(std::initializer_list<const char *> presets) { this->preset_modes_ = presets; }
   fan::FanTraits get_traits() override { return this->traits_; }
 
@@ -21,7 +21,7 @@ class TemplateFan final : public Component, public fan::Fan {
 
   bool has_oscillating_{false};
   bool has_direction_{false};
-  uint8_t speed_count_{0};
+  int speed_count_{0};
   fan::FanTraits traits_;
   std::vector<const char *> preset_modes_{};
 };

esphome/components/time/posix_tz.cpp

@@ -1,481 +0,0 @@
-#include "esphome/core/defines.h"
-
-#ifdef USE_TIME_TIMEZONE
-
-#include "posix_tz.h"
-#include <cctype>
-
-namespace esphome::time {
-
-// Global timezone - set once at startup, rarely changes
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables) - intentional mutable state
-static ParsedTimezone global_tz_{};
-
-void set_global_tz(const ParsedTimezone &tz) { global_tz_ = tz; }
-
-const ParsedTimezone &get_global_tz() { return global_tz_; }
-
-namespace internal {
-
-// Helper to parse an unsigned integer from string, updating pointer
-static uint32_t parse_uint(const char *&p) {
-  uint32_t value = 0;
-  while (std::isdigit(static_cast<unsigned char>(*p))) {
-    value = value * 10 + (*p - '0');
-    p++;
-  }
-  return value;
-}
-
-bool is_leap_year(int year) { return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0); }
-
-// Get days in year (avoids duplicate is_leap_year calls)
-static inline int days_in_year(int year) { return is_leap_year(year) ? 366 : 365; }
-
-// Convert days since epoch to year, updating days to remainder
-static int __attribute__((noinline)) days_to_year(int64_t &days) {
-  int year = 1970;
-  int diy;
-  while (days >= (diy = days_in_year(year))) {
-    days -= diy;
-    year++;
-  }
-  while (days < 0) {
-    year--;
-    days += days_in_year(year);
-  }
-  return year;
-}
-
-// Extract just the year from a UTC epoch
-static int epoch_to_year(time_t epoch) {
-  int64_t days = epoch / 86400;
-  if (epoch < 0 && epoch % 86400 != 0)
-    days--;
-  return days_to_year(days);
-}
-
-int days_in_month(int year, int month) {
-  switch (month) {
-    case 2:
-      return is_leap_year(year) ? 29 : 28;
-    case 4:
-    case 6:
-    case 9:
-    case 11:
-      return 30;
-    default:
-      return 31;
-  }
-}
-
-// Zeller-like algorithm for day of week (0 = Sunday)
-int __attribute__((noinline)) day_of_week(int year, int month, int day) {
-  // Adjust for January/February
-  if (month < 3) {
-    month += 12;
-    year--;
-  }
-  int k = year % 100;
-  int j = year / 100;
-  int h = (day + (13 * (month + 1)) / 5 + k + k / 4 + j / 4 - 2 * j) % 7;
-  // Convert from Zeller (0=Sat) to standard (0=Sun)
-  return ((h + 6) % 7);
-}
-
-void __attribute__((noinline)) epoch_to_tm_utc(time_t epoch, struct tm *out_tm) {
-  // Days since epoch
-  int64_t days = epoch / 86400;
-  int32_t remaining_secs = epoch % 86400;
-  if (remaining_secs < 0) {
-    days--;
-    remaining_secs += 86400;
-  }
-
-  out_tm->tm_sec = remaining_secs % 60;
-  remaining_secs /= 60;
-  out_tm->tm_min = remaining_secs % 60;
-  out_tm->tm_hour = remaining_secs / 60;
-
-  // Day of week (Jan 1, 1970 was Thursday = 4)
-  out_tm->tm_wday = static_cast<int>((days + 4) % 7);
-  if (out_tm->tm_wday < 0)
-    out_tm->tm_wday += 7;
-
-  // Calculate year (updates days to day-of-year)
-  int year = days_to_year(days);
-  out_tm->tm_year = year - 1900;
-  out_tm->tm_yday = static_cast<int>(days);
-
-  // Calculate month and day
-  int month = 1;
-  int dim;
-  while (days >= (dim = days_in_month(year, month))) {
-    days -= dim;
-    month++;
-  }
-
-  out_tm->tm_mon = month - 1;
-  out_tm->tm_mday = static_cast<int>(days) + 1;
-  out_tm->tm_isdst = 0;
-}
-
-bool skip_tz_name(const char *&p) {
-  if (*p == '<') {
-    // Angle-bracket quoted name: <+07>, <-03>, <AEST>
-    p++;  // skip '<'
-    while (*p && *p != '>') {
-      p++;
-    }
-    if (*p == '>') {
-      p++;  // skip '>'
-      return true;
-    }
-    return false;  // Unterminated
-  }
-
-  // Standard name: 3+ letters
-  const char *start = p;
-  while (*p && std::isalpha(static_cast<unsigned char>(*p))) {
-    p++;
-  }
-  return (p - start) >= 3;
-}
-
-int32_t __attribute__((noinline)) parse_offset(const char *&p) {
-  int sign = 1;
-  if (*p == '-') {
-    sign = -1;
-    p++;
-  } else if (*p == '+') {
-    p++;
-  }
-
-  int hours = parse_uint(p);
-  int minutes = 0;
-  int seconds = 0;
-
-  if (*p == ':') {
-    p++;
-    minutes = parse_uint(p);
-    if (*p == ':') {
-      p++;
-      seconds = parse_uint(p);
-    }
-  }
-
-  return sign * (hours * 3600 + minutes * 60 + seconds);
-}
-
-// Helper to parse the optional /time suffix (reuses parse_offset logic)
-static void parse_transition_time(const char *&p, DSTRule &rule) {
-  rule.time_seconds = 2 * 3600;  // Default 02:00
-  if (*p == '/') {
-    p++;
-    rule.time_seconds = parse_offset(p);
-  }
-}
-
-void __attribute__((noinline)) julian_to_month_day(int julian_day, int &out_month, int &out_day) {
-  // J format: day 1-365, Feb 29 is NOT counted even in leap years
-  // So day 60 is always March 1
-  // Iterate forward through months (no array needed)
-  int remaining = julian_day;
-  out_month = 1;
-  while (out_month <= 12) {
-    // Days in month for non-leap year (J format ignores leap years)
-    int dim = days_in_month(2001, out_month);  // 2001 is non-leap year
-    if (remaining <= dim) {
-      out_day = remaining;
-      return;
-    }
-    remaining -= dim;
-    out_month++;
-  }
-  out_day = remaining;
-}
-
-void __attribute__((noinline)) day_of_year_to_month_day(int day_of_year, int year, int &out_month, int &out_day) {
-  // Plain format: day 0-365, Feb 29 IS counted in leap years
-  // Day 0 = Jan 1
-  int remaining = day_of_year;
-  out_month = 1;
-
-  while (out_month <= 12) {
-    int days_this_month = days_in_month(year, out_month);
-    if (remaining < days_this_month) {
-      out_day = remaining + 1;
-      return;
-    }
-    remaining -= days_this_month;
-    out_month++;
-  }
-
-  // Shouldn't reach here with valid input
-  out_month = 12;
-  out_day = 31;
-}
-
-bool parse_dst_rule(const char *&p, DSTRule &rule) {
-  rule = {};  // Zero initialize
-
-  if (*p == 'M' || *p == 'm') {
-    // M format: Mm.w.d (month.week.day)
-    rule.type = DSTRuleType::MONTH_WEEK_DAY;
-    p++;
-
-    rule.month = parse_uint(p);
-    if (rule.month < 1 || rule.month > 12)
-      return false;
-
-    if (*p++ != '.')
-      return false;
-
-    rule.week = parse_uint(p);
-    if (rule.week < 1 || rule.week > 5)
-      return false;
-
-    if (*p++ != '.')
-      return false;
-
-    rule.day_of_week = parse_uint(p);
-    if (rule.day_of_week > 6)
-      return false;
-
-  } else if (*p == 'J' || *p == 'j') {
-    // J format: Jn (Julian day 1-365, not counting Feb 29)
-    rule.type = DSTRuleType::JULIAN_NO_LEAP;
-    p++;
-
-    rule.day = parse_uint(p);
-    if (rule.day < 1 || rule.day > 365)
-      return false;
-
-  } else if (std::isdigit(static_cast<unsigned char>(*p))) {
-    // Plain number format: n (day 0-365, counting Feb 29)
-    rule.type = DSTRuleType::DAY_OF_YEAR;
-
-    rule.day = parse_uint(p);
-    if (rule.day > 365)
-      return false;
-
-  } else {
-    return false;
-  }
-
-  // Parse optional /time suffix
-  parse_transition_time(p, rule);
-
-  return true;
-}
-
-// Calculate days from Jan 1 of given year to given month/day
-static int __attribute__((noinline)) days_from_year_start(int year, int month, int day) {
-  int days = day - 1;
-  for (int m = 1; m < month; m++) {
-    days += days_in_month(year, m);
-  }
-  return days;
-}
-
-// Calculate days from epoch to Jan 1 of given year (for DST transition calculations)
-// Only supports years >= 1970. Timezone is either compiled in from YAML or set by
-// Home Assistant, so pre-1970 dates are not a concern.
-static int64_t __attribute__((noinline)) days_to_year_start(int year) {
-  int64_t days = 0;
-  for (int y = 1970; y < year; y++) {
-    days += days_in_year(y);
-  }
-  return days;
-}
-
-time_t __attribute__((noinline)) calculate_dst_transition(int year, const DSTRule &rule, int32_t base_offset_seconds) {
-  int month, day;
-
-  switch (rule.type) {
-    case DSTRuleType::MONTH_WEEK_DAY: {
-      // Find the nth occurrence of day_of_week in the given month
-      int first_dow = day_of_week(year, rule.month, 1);
-
-      // Days until first occurrence of target day
-      int days_until_first = (rule.day_of_week - first_dow + 7) % 7;
-      int first_occurrence = 1 + days_until_first;
-
-      if (rule.week == 5) {
-        // "Last" occurrence - find the last one in the month
-        int dim = days_in_month(year, rule.month);
-        day = first_occurrence;
-        while (day + 7 <= dim) {
-          day += 7;
-        }
-      } else {
-        // nth occurrence
-        day = first_occurrence + (rule.week - 1) * 7;
-      }
-      month = rule.month;
-      break;
-    }
-
-    case DSTRuleType::JULIAN_NO_LEAP:
-      // J format: day 1-365, Feb 29 not counted
-      julian_to_month_day(rule.day, month, day);
-      break;
-
-    case DSTRuleType::DAY_OF_YEAR:
-      // Plain format: day 0-365, Feb 29 counted
-      day_of_year_to_month_day(rule.day, year, month, day);
-      break;
-
-    case DSTRuleType::NONE:
-      // Should never be called with NONE, but handle it gracefully
-      month = 1;
-      day = 1;
-      break;
-  }
-
-  // Calculate days from epoch to this date
-  int64_t days = days_to_year_start(year) + days_from_year_start(year, month, day);
-
-  // Convert to epoch and add transition time and base offset
-  return days * 86400 + rule.time_seconds + base_offset_seconds;
-}
-
-}  // namespace internal
-
-bool __attribute__((noinline)) is_in_dst(time_t utc_epoch, const ParsedTimezone &tz) {
-  if (!tz.has_dst()) {
-    return false;
-  }
-
-  int year = internal::epoch_to_year(utc_epoch);
-
-  // Calculate DST start and end for this year
-  // DST start transition happens in standard time
-  time_t dst_start = internal::calculate_dst_transition(year, tz.dst_start, tz.std_offset_seconds);
-  // DST end transition happens in daylight time
-  time_t dst_end = internal::calculate_dst_transition(year, tz.dst_end, tz.dst_offset_seconds);
-
-  if (dst_start < dst_end) {
-    // Northern hemisphere: DST is between start and end
-    return (utc_epoch >= dst_start && utc_epoch < dst_end);
-  } else {
-    // Southern hemisphere: DST is outside the range (wraps around year)
-    return (utc_epoch >= dst_start || utc_epoch < dst_end);
-  }
-}
-
-bool parse_posix_tz(const char *tz_string, ParsedTimezone &result) {
-  if (!tz_string || !*tz_string) {
-    return false;
-  }
-
-  const char *p = tz_string;
-
-  // Initialize result (dst_start/dst_end default to type=NONE, so has_dst() returns false)
-  result.std_offset_seconds = 0;
-  result.dst_offset_seconds = 0;
-  result.dst_start = {};
-  result.dst_end = {};
-
-  // Skip standard timezone name
-  if (!internal::skip_tz_name(p)) {
-    return false;
-  }
-
-  // Parse standard offset (required)
-  if (!*p || (!std::isdigit(static_cast<unsigned char>(*p)) && *p != '+' && *p != '-')) {
-    return false;
-  }
-  result.std_offset_seconds = internal::parse_offset(p);
-
-  // Check for DST name
-  if (!*p) {
-    return true;  // No DST
-  }
-
-  // If next char is comma, there's no DST name but there are rules (invalid)
-  if (*p == ',') {
-    return false;
-  }
-
-  // Check if there's something that looks like a DST name start
-  // (letter or angle bracket). If not, treat as trailing garbage and return success.
-  if (!std::isalpha(static_cast<unsigned char>(*p)) && *p != '<') {
-    return true;  // No DST, trailing characters ignored
-  }
-
-  if (!internal::skip_tz_name(p)) {
-    return false;  // Invalid DST name (started but malformed)
-  }
-
-  // Optional DST offset (default is std - 1 hour)
-  if (*p && *p != ',' && (std::isdigit(static_cast<unsigned char>(*p)) || *p == '+' || *p == '-')) {
-    result.dst_offset_seconds = internal::parse_offset(p);
-  } else {
-    result.dst_offset_seconds = result.std_offset_seconds - 3600;
-  }
-
-  // Parse DST rules (required when DST name is present)
-  if (*p != ',') {
-    // DST name without rules - treat as no DST since we can't determine transitions
-    return true;
-  }
-
-  p++;
-  if (!internal::parse_dst_rule(p, result.dst_start)) {
-    return false;
-  }
-
-  // Second rule is required per POSIX
-  if (*p != ',') {
-    return false;
-  }
-  p++;
-  // has_dst() now returns true since dst_start.type was set by parse_dst_rule
-  return internal::parse_dst_rule(p, result.dst_end);
-}
-
-bool epoch_to_local_tm(time_t utc_epoch, const ParsedTimezone &tz, struct tm *out_tm) {
-  if (!out_tm) {
-    return false;
-  }
-
-  // Determine DST status once (avoids duplicate is_in_dst calculation)
-  bool in_dst = is_in_dst(utc_epoch, tz);
-  int32_t offset = in_dst ? tz.dst_offset_seconds : tz.std_offset_seconds;
-
-  // Apply offset (POSIX offset is positive west, so subtract to get local)
-  time_t local_epoch = utc_epoch - offset;
-
-  internal::epoch_to_tm_utc(local_epoch, out_tm);
-  out_tm->tm_isdst = in_dst ? 1 : 0;
-
-  return true;
-}
-
-}  // namespace esphome::time
-
-#ifndef USE_HOST
-// Override libc's localtime functions to use our timezone on embedded platforms.
-// This allows user lambdas calling ::localtime() to get correct local time
-// without needing the TZ environment variable (which pulls in scanf bloat).
-// On host, we use the normal TZ mechanism since there's no memory constraint.
-
-// Thread-safe version
-extern "C" struct tm *localtime_r(const time_t *timer, struct tm *result) {
-  if (timer == nullptr || result == nullptr) {
-    return nullptr;
-  }
-  esphome::time::epoch_to_local_tm(*timer, esphome::time::get_global_tz(), result);
-  return result;
-}
-
-// Non-thread-safe version (uses static buffer, standard libc behavior)
-extern "C" struct tm *localtime(const time_t *timer) {
-  // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-  static struct tm localtime_buf;
-  return localtime_r(timer, &localtime_buf);
-}
-#endif  // !USE_HOST
-
-#endif  // USE_TIME_TIMEZONE

esphome/components/time/posix_tz.h

@@ -1,132 +0,0 @@
-#pragma once
-
-#ifdef USE_TIME_TIMEZONE
-
-#include <cstdint>
-#include <ctime>
-
-namespace esphome::time {
-
-/// Type of DST transition rule
-enum class DSTRuleType : uint8_t {
-  NONE = 0,        ///< No DST rule (used to indicate no DST)
-  MONTH_WEEK_DAY,  ///< M format: Mm.w.d (e.g., M3.2.0 = 2nd Sunday of March)
-  JULIAN_NO_LEAP,  ///< J format: Jn (day 1-365, Feb 29 not counted)
-  DAY_OF_YEAR,     ///< Plain number: n (day 0-365, Feb 29 counted in leap years)
-};
-
-/// Rule for DST transition (packed for 32-bit: 12 bytes)
-struct DSTRule {
-  int32_t time_seconds;  ///< Seconds after midnight (default 7200 = 2:00 AM)
-  uint16_t day;          ///< Day of year (for JULIAN_NO_LEAP and DAY_OF_YEAR)
-  DSTRuleType type;      ///< Type of rule
-  uint8_t month;         ///< Month 1-12 (for MONTH_WEEK_DAY)
-  uint8_t week;          ///< Week 1-5, 5 = last (for MONTH_WEEK_DAY)
-  uint8_t day_of_week;   ///< Day 0-6, 0 = Sunday (for MONTH_WEEK_DAY)
-};
-
-/// Parsed POSIX timezone information (packed for 32-bit: 32 bytes)
-struct ParsedTimezone {
-  int32_t std_offset_seconds;  ///< Standard time offset from UTC in seconds (positive = west)
-  int32_t dst_offset_seconds;  ///< DST offset from UTC in seconds
-  DSTRule dst_start;           ///< When DST starts
-  DSTRule dst_end;             ///< When DST ends
-
-  /// Check if this timezone has DST rules
-  bool has_dst() const { return this->dst_start.type != DSTRuleType::NONE; }
-};
-
-/// Parse a POSIX TZ string into a ParsedTimezone struct.
-/// Supports formats like:
-///   - "EST5" (simple offset, no DST)
-///   - "EST5EDT,M3.2.0,M11.1.0" (with DST, M-format rules)
-///   - "CST6CDT,M3.2.0/2,M11.1.0/2" (with transition times)
-///   - "<+07>-7" (angle-bracket notation for special names)
-///   - "IST-5:30" (half-hour offsets)
-///   - "EST5EDT,J60,J300" (J-format: Julian day without leap day)
-///   - "EST5EDT,60,300" (plain day number: day of year with leap day)
-/// @param tz_string The POSIX TZ string to parse
-/// @param result Output: the parsed timezone data
-/// @return true if parsing succeeded, false on error
-bool parse_posix_tz(const char *tz_string, ParsedTimezone &result);
-
-/// Convert a UTC epoch to local time using the parsed timezone.
-/// This replaces libc's localtime() to avoid scanf dependency.
-/// @param utc_epoch Unix timestamp in UTC
-/// @param tz The parsed timezone
-/// @param[out] out_tm Output tm struct with local time
-/// @return true on success
-bool epoch_to_local_tm(time_t utc_epoch, const ParsedTimezone &tz, struct tm *out_tm);
-
-/// Set the global timezone used by epoch_to_local_tm() when called without a timezone.
-/// This is called by RealTimeClock::apply_timezone_() to enable ESPTime::from_epoch_local()
-/// to work without libc's localtime().
-void set_global_tz(const ParsedTimezone &tz);
-
-/// Get the global timezone.
-const ParsedTimezone &get_global_tz();
-
-/// Check if a given UTC epoch falls within DST for the parsed timezone.
-/// @param utc_epoch Unix timestamp in UTC
-/// @param tz The parsed timezone
-/// @return true if DST is in effect at the given time
-bool is_in_dst(time_t utc_epoch, const ParsedTimezone &tz);
-
-// Internal helper functions exposed for testing
-
-namespace internal {
-
-/// Skip a timezone name (letters or <...> quoted format)
-/// @param p Pointer to current position, updated on return
-/// @return true if a valid name was found
-bool skip_tz_name(const char *&p);
-
-/// Parse an offset in format [-]hh[:mm[:ss]]
-/// @param p Pointer to current position, updated on return
-/// @return Offset in seconds
-int32_t parse_offset(const char *&p);
-
-/// Parse a DST rule in format Mm.w.d[/time], Jn[/time], or n[/time]
-/// @param p Pointer to current position, updated on return
-/// @param rule Output: the parsed rule
-/// @return true if parsing succeeded
-bool parse_dst_rule(const char *&p, DSTRule &rule);
-
-/// Convert Julian day (J format, 1-365 not counting Feb 29) to month/day
-/// @param julian_day Day number 1-365
-/// @param[out] month Output: month 1-12
-/// @param[out] day Output: day of month
-void julian_to_month_day(int julian_day, int &month, int &day);
-
-/// Convert day of year (plain format, 0-365 counting Feb 29) to month/day
-/// @param day_of_year Day number 0-365
-/// @param year The year (for leap year calculation)
-/// @param[out] month Output: month 1-12
-/// @param[out] day Output: day of month
-void day_of_year_to_month_day(int day_of_year, int year, int &month, int &day);
-
-/// Calculate day of week for any date (0 = Sunday)
-/// Uses a simplified algorithm that works for years 1970-2099
-int day_of_week(int year, int month, int day);
-
-/// Get the number of days in a month
-int days_in_month(int year, int month);
-
-/// Check if a year is a leap year
-bool is_leap_year(int year);
-
-/// Convert epoch to year/month/day/hour/min/sec (UTC)
-void epoch_to_tm_utc(time_t epoch, struct tm *out_tm);
-
-/// Calculate the epoch timestamp for a DST transition in a given year.
-/// @param year The year (e.g., 2026)
-/// @param rule The DST rule (month, week, day_of_week, time)
-/// @param base_offset_seconds The timezone offset to apply (std or dst depending on context)
-/// @return Unix epoch timestamp of the transition
-time_t calculate_dst_transition(int year, const DSTRule &rule, int32_t base_offset_seconds);
-
-}  // namespace internal
-
-}  // namespace esphome::time
-
-#endif  // USE_TIME_TIMEZONE

esphome/components/time/real_time_clock.cpp

@@ -14,8 +14,8 @@
 #include <sys/time.h>
 #endif
 #include <cerrno>
+
 #include <cinttypes>
-#include <cstdlib>
 
 namespace esphome::time {
 
@@ -23,33 +23,9 @@ static const char *const TAG = "time";
 
 RealTimeClock::RealTimeClock() = default;
 
-ESPTime __attribute__((noinline)) RealTimeClock::now() {
-#ifdef USE_TIME_TIMEZONE
-  time_t epoch = this->timestamp_now();
-  struct tm local_tm;
-  if (epoch_to_local_tm(epoch, get_global_tz(), &local_tm)) {
-    return ESPTime::from_c_tm(&local_tm, epoch);
-  }
-  // Fallback to UTC if parsing failed
-  return ESPTime::from_epoch_utc(epoch);
-#else
-  return ESPTime::from_epoch_local(this->timestamp_now());
-#endif
-}
-
 void RealTimeClock::dump_config() {
 #ifdef USE_TIME_TIMEZONE
-  const auto &tz = get_global_tz();
-  // POSIX offset is positive west, negate for conventional UTC+X display
-  int std_h = -tz.std_offset_seconds / 3600;
-  int std_m = (std::abs(tz.std_offset_seconds) % 3600) / 60;
-  if (tz.has_dst()) {
-    int dst_h = -tz.dst_offset_seconds / 3600;
-    int dst_m = (std::abs(tz.dst_offset_seconds) % 3600) / 60;
-    ESP_LOGCONFIG(TAG, "Timezone: UTC%+d:%02d (DST UTC%+d:%02d)", std_h, std_m, dst_h, dst_m);
-  } else {
-    ESP_LOGCONFIG(TAG, "Timezone: UTC%+d:%02d", std_h, std_m);
-  }
+  ESP_LOGCONFIG(TAG, "Timezone: '%s'", this->timezone_.c_str());
 #endif
   auto time = this->now();
   ESP_LOGCONFIG(TAG, "Current time: %04d-%02d-%02d %02d:%02d:%02d", time.year, time.month, time.day_of_month, time.hour,
@@ -96,6 +72,11 @@ void RealTimeClock::synchronize_epoch_(uint32_t epoch) {
     ret = settimeofday(&timev, nullptr);
   }
 
+#ifdef USE_TIME_TIMEZONE
+  // Move timezone back to local timezone.
+  this->apply_timezone_();
+#endif
+
   if (ret != 0) {
     ESP_LOGW(TAG, "setimeofday() failed with code %d", ret);
   }
@@ -108,29 +89,9 @@ void RealTimeClock::synchronize_epoch_(uint32_t epoch) {
 }
 
 #ifdef USE_TIME_TIMEZONE
-void RealTimeClock::apply_timezone_(const char *tz) {
-  ParsedTimezone parsed{};
-
-  // Handle null or empty input - use UTC
-  if (tz == nullptr || *tz == '\0') {
-    set_global_tz(parsed);
-    return;
-  }
-
-#ifdef USE_HOST
-  // On host platform, also set TZ environment variable for libc compatibility
-  setenv("TZ", tz, 1);
+void RealTimeClock::apply_timezone_() {
+  setenv("TZ", this->timezone_.c_str(), 1);
   tzset();
-#endif
-
-  // Parse the POSIX TZ string using our custom parser
-  if (!parse_posix_tz(tz, parsed)) {
-    ESP_LOGW(TAG, "Failed to parse timezone: %s", tz);
-    // parsed stays as default (UTC) on failure
-  }
-
-  // Set global timezone for all time conversions
-  set_global_tz(parsed);
 }
 #endif
 

esphome/components/time/real_time_clock.h

@@ -6,9 +6,6 @@
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/time.h"
-#ifdef USE_TIME_TIMEZONE
-#include "posix_tz.h"
-#endif
 
 namespace esphome::time {
 
@@ -23,31 +20,26 @@ class RealTimeClock : public PollingComponent {
   explicit RealTimeClock();
 
 #ifdef USE_TIME_TIMEZONE
-  /// Set the time zone from a POSIX TZ string.
-  void set_timezone(const char *tz) { this->apply_timezone_(tz); }
-
-  /// Set the time zone from a character buffer with known length.
-  /// The buffer does not need to be null-terminated.
-  void set_timezone(const char *tz, size_t len) {
-    if (tz == nullptr) {
-      this->apply_timezone_(nullptr);
-      return;
-    }
-    // Stack buffer - TZ strings from tzdata are typically short (< 50 chars)
-    char buf[128];
-    if (len >= sizeof(buf))
-      len = sizeof(buf) - 1;
-    memcpy(buf, tz, len);
-    buf[len] = '\0';
-    this->apply_timezone_(buf);
+  /// Set the time zone.
+  void set_timezone(const std::string &tz) {
+    this->timezone_ = tz;
+    this->apply_timezone_();
   }
 
-  /// Set the time zone from a std::string.
-  void set_timezone(const std::string &tz) { this->apply_timezone_(tz.c_str()); }
+  /// Set the time zone from raw buffer, only if it differs from the current one.
+  void set_timezone(const char *tz, size_t len) {
+    if (this->timezone_.length() != len || memcmp(this->timezone_.c_str(), tz, len) != 0) {
+      this->timezone_.assign(tz, len);
+      this->apply_timezone_();
+    }
+  }
+
+  /// Get the time zone currently in use.
+  std::string get_timezone() { return this->timezone_; }
 #endif
 
   /// Get the time in the currently defined timezone.
-  ESPTime now();
+  ESPTime now() { return ESPTime::from_epoch_local(this->timestamp_now()); }
 
   /// Get the time without any time zone or DST corrections.
   ESPTime utcnow() { return ESPTime::from_epoch_utc(this->timestamp_now()); }
@@ -66,7 +58,8 @@ class RealTimeClock : public PollingComponent {
   void synchronize_epoch_(uint32_t epoch);
 
 #ifdef USE_TIME_TIMEZONE
-  void apply_timezone_(const char *tz);
+  std::string timezone_{};
+  void apply_timezone_();
 #endif
 
   LazyCallbackManager<void()> time_sync_callback_;

esphome/components/tuya/fan/__init__.py

@@ -22,7 +22,7 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_SPEED_DATAPOINT): cv.uint8_t,
             cv.Optional(CONF_SWITCH_DATAPOINT): cv.uint8_t,
             cv.Optional(CONF_DIRECTION_DATAPOINT): cv.uint8_t,
-            cv.Optional(CONF_SPEED_COUNT, default=3): cv.int_range(min=1, max=255),
+            cv.Optional(CONF_SPEED_COUNT, default=3): cv.int_range(min=1, max=256),
         }
     )
     .extend(cv.COMPONENT_SCHEMA),

esphome/components/tuya/fan/tuya_fan.h

@@ -9,7 +9,7 @@ namespace tuya {
 
 class TuyaFan : public Component, public fan::Fan {
  public:
-  TuyaFan(Tuya *parent, uint8_t speed_count) : parent_(parent), speed_count_(speed_count) {}
+  TuyaFan(Tuya *parent, int speed_count) : parent_(parent), speed_count_(speed_count) {}
   void setup() override;
   void dump_config() override;
   void set_speed_id(uint8_t speed_id) { this->speed_id_ = speed_id; }
@@ -27,7 +27,7 @@ class TuyaFan : public Component, public fan::Fan {
   optional<uint8_t> switch_id_{};
   optional<uint8_t> oscillation_id_{};
   optional<uint8_t> direction_id_{};
-  uint8_t speed_count_{};
+  int speed_count_{};
   TuyaDatapointType speed_type_{};
   TuyaDatapointType oscillation_type_{};
 };

esphome/components/web_server/web_server.cpp

@@ -1,4 +1,3 @@
-// Trigger CI memory impact (uses updated ESPAsyncWebServer from web_server_base)
 #include "web_server.h"
 #ifdef USE_WEBSERVER
 #include "esphome/components/json/json_util.h"
@@ -215,7 +214,7 @@ DeferredUpdateEventSource::deq_push_back_with_dedup_(void *source, message_gener
 void DeferredUpdateEventSource::process_deferred_queue_() {
   while (!deferred_queue_.empty()) {
     DeferredEvent &de = deferred_queue_.front();
-    auto message = de.message_generator_(web_server_, de.source_);
+    std::string message = de.message_generator_(web_server_, de.source_);
     if (this->send(message.c_str(), "state") != DISCARDED) {
       // O(n) but memory efficiency is more important than speed here which is why std::vector was chosen
       deferred_queue_.erase(deferred_queue_.begin());
@@ -272,7 +271,7 @@ void DeferredUpdateEventSource::deferrable_send_state(void *source, const char *
     // deferred queue still not empty which means downstream event queue full, no point trying to send first
     deq_push_back_with_dedup_(source, message_generator);
   } else {
-    auto message = message_generator(web_server_, source);
+    std::string message = message_generator(web_server_, source);
     if (this->send(message.c_str(), "state") == DISCARDED) {
       deq_push_back_with_dedup_(source, message_generator);
     } else {
@@ -326,7 +325,7 @@ void DeferredUpdateEventSourceList::on_client_connect_(DeferredUpdateEventSource
   ws->defer([ws, source]() {
     // Configure reconnect timeout and send config
     // this should always go through since the AsyncEventSourceClient event queue is empty on connect
-    auto message = ws->get_config_json();
+    std::string message = ws->get_config_json();
     source->try_send_nodefer(message.c_str(), "ping", millis(), 30000);
 
 #ifdef USE_WEBSERVER_SORTING
@@ -335,10 +334,10 @@ void DeferredUpdateEventSourceList::on_client_connect_(DeferredUpdateEventSource
       JsonObject root = builder.root();
       root[ESPHOME_F("name")] = group.second.name;
       root[ESPHOME_F("sorting_weight")] = group.second.weight;
-      auto group_msg = builder.serialize();
+      message = builder.serialize();
 
       // up to 31 groups should be able to be queued initially without defer
-      source->try_send_nodefer(group_msg.c_str(), "sorting_group");
+      source->try_send_nodefer(message.c_str(), "sorting_group");
     }
 #endif
 
@@ -371,7 +370,7 @@ void WebServer::set_css_include(const char *css_include) { this->css_include_ =
 void WebServer::set_js_include(const char *js_include) { this->js_include_ = js_include; }
 #endif
 
-json::SerializationBuffer<> WebServer::get_config_json() {
+std::string WebServer::get_config_json() {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -604,20 +603,20 @@ void WebServer::handle_sensor_request(AsyncWebServerRequest *request, const UrlM
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->sensor_json_(obj, obj->state, detail);
+      std::string data = this->sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::sensor_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::sensor_state_json_generator(WebServer *web_server, void *source) {
   return web_server->sensor_json_((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::sensor_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::sensor_all_json_generator(WebServer *web_server, void *source) {
   return web_server->sensor_json_((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config) {
+std::string WebServer::sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -651,23 +650,23 @@ void WebServer::handle_text_sensor_request(AsyncWebServerRequest *request, const
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->text_sensor_json_(obj, obj->state, detail);
+      std::string data = this->text_sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::text_sensor_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::text_sensor_state_json_generator(WebServer *web_server, void *source) {
   return web_server->text_sensor_json_((text_sensor::TextSensor *) (source),
                                        ((text_sensor::TextSensor *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::text_sensor_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::text_sensor_all_json_generator(WebServer *web_server, void *source) {
   return web_server->text_sensor_json_((text_sensor::TextSensor *) (source),
                                        ((text_sensor::TextSensor *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value,
-                                                         JsonDetail start_config) {
+std::string WebServer::text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value,
+                                         JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -712,7 +711,7 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->switch_json_(obj, obj->state, detail);
+      std::string data = this->switch_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -737,13 +736,13 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::switch_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::switch_state_json_generator(WebServer *web_server, void *source) {
   return web_server->switch_json_((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::switch_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::switch_all_json_generator(WebServer *web_server, void *source) {
   return web_server->switch_json_((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config) {
+std::string WebServer::switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -765,7 +764,7 @@ void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlM
       continue;
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->button_json_(obj, detail);
+      std::string data = this->button_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("press"))) {
       DEFER_ACTION(obj, obj->press());
@@ -778,10 +777,10 @@ void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlM
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::button_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::button_all_json_generator(WebServer *web_server, void *source) {
   return web_server->button_json_((button::Button *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::button_json_(button::Button *obj, JsonDetail start_config) {
+std::string WebServer::button_json_(button::Button *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -808,23 +807,22 @@ void WebServer::handle_binary_sensor_request(AsyncWebServerRequest *request, con
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->binary_sensor_json_(obj, obj->state, detail);
+      std::string data = this->binary_sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::binary_sensor_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::binary_sensor_state_json_generator(WebServer *web_server, void *source) {
   return web_server->binary_sensor_json_((binary_sensor::BinarySensor *) (source),
                                          ((binary_sensor::BinarySensor *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::binary_sensor_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::binary_sensor_all_json_generator(WebServer *web_server, void *source) {
   return web_server->binary_sensor_json_((binary_sensor::BinarySensor *) (source),
                                          ((binary_sensor::BinarySensor *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value,
-                                                           JsonDetail start_config) {
+std::string WebServer::binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -851,7 +849,7 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->fan_json_(obj, detail);
+      std::string data = this->fan_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("toggle"))) {
       DEFER_ACTION(obj, obj->toggle().perform());
@@ -892,13 +890,13 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::fan_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::fan_state_json_generator(WebServer *web_server, void *source) {
   return web_server->fan_json_((fan::Fan *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::fan_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::fan_all_json_generator(WebServer *web_server, void *source) {
   return web_server->fan_json_((fan::Fan *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::fan_json_(fan::Fan *obj, JsonDetail start_config) {
+std::string WebServer::fan_json_(fan::Fan *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -932,7 +930,7 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->light_json_(obj, detail);
+      std::string data = this->light_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals(ESPHOME_F("toggle"))) {
       DEFER_ACTION(obj, obj->toggle().perform());
@@ -971,13 +969,13 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::light_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::light_state_json_generator(WebServer *web_server, void *source) {
   return web_server->light_json_((light::LightState *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::light_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::light_all_json_generator(WebServer *web_server, void *source) {
   return web_server->light_json_((light::LightState *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::light_json_(light::LightState *obj, JsonDetail start_config) {
+std::string WebServer::light_json_(light::LightState *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1011,7 +1009,7 @@ void WebServer::handle_cover_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->cover_json_(obj, detail);
+      std::string data = this->cover_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1059,13 +1057,13 @@ void WebServer::handle_cover_request(AsyncWebServerRequest *request, const UrlMa
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::cover_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::cover_state_json_generator(WebServer *web_server, void *source) {
   return web_server->cover_json_((cover::Cover *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::cover_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::cover_all_json_generator(WebServer *web_server, void *source) {
   return web_server->cover_json_((cover::Cover *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::cover_json_(cover::Cover *obj, JsonDetail start_config) {
+std::string WebServer::cover_json_(cover::Cover *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1100,7 +1098,7 @@ void WebServer::handle_number_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->number_json_(obj, obj->state, detail);
+      std::string data = this->number_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1119,13 +1117,13 @@ void WebServer::handle_number_request(AsyncWebServerRequest *request, const UrlM
   request->send(404);
 }
 
-json::SerializationBuffer<> WebServer::number_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::number_state_json_generator(WebServer *web_server, void *source) {
   return web_server->number_json_((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::number_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::number_all_json_generator(WebServer *web_server, void *source) {
   return web_server->number_json_((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::number_json_(number::Number *obj, float value, JsonDetail start_config) {
+std::string WebServer::number_json_(number::Number *obj, float value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1167,7 +1165,7 @@ void WebServer::handle_date_request(AsyncWebServerRequest *request, const UrlMat
       continue;
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->date_json_(obj, detail);
+      std::string data = this->date_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1193,13 +1191,13 @@ void WebServer::handle_date_request(AsyncWebServerRequest *request, const UrlMat
   request->send(404);
 }
 
-json::SerializationBuffer<> WebServer::date_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::date_state_json_generator(WebServer *web_server, void *source) {
   return web_server->date_json_((datetime::DateEntity *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::date_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::date_all_json_generator(WebServer *web_server, void *source) {
   return web_server->date_json_((datetime::DateEntity *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::date_json_(datetime::DateEntity *obj, JsonDetail start_config) {
+std::string WebServer::date_json_(datetime::DateEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1228,7 +1226,7 @@ void WebServer::handle_time_request(AsyncWebServerRequest *request, const UrlMat
       continue;
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->time_json_(obj, detail);
+      std::string data = this->time_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1253,13 +1251,13 @@ void WebServer::handle_time_request(AsyncWebServerRequest *request, const UrlMat
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::time_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::time_state_json_generator(WebServer *web_server, void *source) {
   return web_server->time_json_((datetime::TimeEntity *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::time_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::time_all_json_generator(WebServer *web_server, void *source) {
   return web_server->time_json_((datetime::TimeEntity *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::time_json_(datetime::TimeEntity *obj, JsonDetail start_config) {
+std::string WebServer::time_json_(datetime::TimeEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1288,7 +1286,7 @@ void WebServer::handle_datetime_request(AsyncWebServerRequest *request, const Ur
       continue;
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->datetime_json_(obj, detail);
+      std::string data = this->datetime_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1313,13 +1311,13 @@ void WebServer::handle_datetime_request(AsyncWebServerRequest *request, const Ur
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::datetime_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::datetime_state_json_generator(WebServer *web_server, void *source) {
   return web_server->datetime_json_((datetime::DateTimeEntity *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::datetime_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::datetime_all_json_generator(WebServer *web_server, void *source) {
   return web_server->datetime_json_((datetime::DateTimeEntity *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config) {
+std::string WebServer::datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1350,7 +1348,7 @@ void WebServer::handle_text_request(AsyncWebServerRequest *request, const UrlMat
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->text_json_(obj, obj->state, detail);
+      std::string data = this->text_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1369,13 +1367,13 @@ void WebServer::handle_text_request(AsyncWebServerRequest *request, const UrlMat
   request->send(404);
 }
 
-json::SerializationBuffer<> WebServer::text_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::text_state_json_generator(WebServer *web_server, void *source) {
   return web_server->text_json_((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::text_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::text_all_json_generator(WebServer *web_server, void *source) {
   return web_server->text_json_((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::text_json_(text::Text *obj, const std::string &value, JsonDetail start_config) {
+std::string WebServer::text_json_(text::Text *obj, const std::string &value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1407,7 +1405,7 @@ void WebServer::handle_select_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->select_json_(obj, obj->has_state() ? obj->current_option() : StringRef(), detail);
+      std::string data = this->select_json_(obj, obj->has_state() ? obj->current_option() : StringRef(), detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1426,15 +1424,15 @@ void WebServer::handle_select_request(AsyncWebServerRequest *request, const UrlM
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::select_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::select_state_json_generator(WebServer *web_server, void *source) {
   auto *obj = (select::Select *) (source);
   return web_server->select_json_(obj, obj->has_state() ? obj->current_option() : StringRef(), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::select_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::select_all_json_generator(WebServer *web_server, void *source) {
   auto *obj = (select::Select *) (source);
   return web_server->select_json_(obj, obj->has_state() ? obj->current_option() : StringRef(), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::select_json_(select::Select *obj, StringRef value, JsonDetail start_config) {
+std::string WebServer::select_json_(select::Select *obj, StringRef value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1466,7 +1464,7 @@ void WebServer::handle_climate_request(AsyncWebServerRequest *request, const Url
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->climate_json_(obj, detail);
+      std::string data = this->climate_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1499,15 +1497,15 @@ void WebServer::handle_climate_request(AsyncWebServerRequest *request, const Url
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::climate_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::climate_state_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->climate_json_((climate::Climate *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::climate_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::climate_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->climate_json_((climate::Climate *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::climate_json_(climate::Climate *obj, JsonDetail start_config) {
+std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   json::JsonBuilder builder;
   JsonObject root = builder.root();
@@ -1640,7 +1638,7 @@ void WebServer::handle_lock_request(AsyncWebServerRequest *request, const UrlMat
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->lock_json_(obj, obj->state, detail);
+      std::string data = this->lock_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1665,13 +1663,13 @@ void WebServer::handle_lock_request(AsyncWebServerRequest *request, const UrlMat
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::lock_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::lock_state_json_generator(WebServer *web_server, void *source) {
   return web_server->lock_json_((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::lock_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::lock_all_json_generator(WebServer *web_server, void *source) {
   return web_server->lock_json_((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config) {
+std::string WebServer::lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1699,7 +1697,7 @@ void WebServer::handle_valve_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->valve_json_(obj, detail);
+      std::string data = this->valve_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1745,13 +1743,13 @@ void WebServer::handle_valve_request(AsyncWebServerRequest *request, const UrlMa
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::valve_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::valve_state_json_generator(WebServer *web_server, void *source) {
   return web_server->valve_json_((valve::Valve *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::valve_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::valve_all_json_generator(WebServer *web_server, void *source) {
   return web_server->valve_json_((valve::Valve *) (source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::valve_json_(valve::Valve *obj, JsonDetail start_config) {
+std::string WebServer::valve_json_(valve::Valve *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1784,7 +1782,7 @@ void WebServer::handle_alarm_control_panel_request(AsyncWebServerRequest *reques
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->alarm_control_panel_json_(obj, obj->get_state(), detail);
+      std::string data = this->alarm_control_panel_json_(obj, obj->get_state(), detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1824,19 +1822,19 @@ void WebServer::handle_alarm_control_panel_request(AsyncWebServerRequest *reques
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::alarm_control_panel_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::alarm_control_panel_state_json_generator(WebServer *web_server, void *source) {
   return web_server->alarm_control_panel_json_((alarm_control_panel::AlarmControlPanel *) (source),
                                                ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
                                                DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::alarm_control_panel_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::alarm_control_panel_all_json_generator(WebServer *web_server, void *source) {
   return web_server->alarm_control_panel_json_((alarm_control_panel::AlarmControlPanel *) (source),
                                                ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
                                                DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
-                                                                 alarm_control_panel::AlarmControlPanelState value,
-                                                                 JsonDetail start_config) {
+std::string WebServer::alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
+                                                 alarm_control_panel::AlarmControlPanelState value,
+                                                 JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1865,7 +1863,7 @@ void WebServer::handle_water_heater_request(AsyncWebServerRequest *request, cons
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->water_heater_json_(obj, detail);
+      std::string data = this->water_heater_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1901,14 +1899,14 @@ void WebServer::handle_water_heater_request(AsyncWebServerRequest *request, cons
   request->send(404);
 }
 
-json::SerializationBuffer<> WebServer::water_heater_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::water_heater_state_json_generator(WebServer *web_server, void *source) {
   return web_server->water_heater_json_(static_cast<water_heater::WaterHeater *>(source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::water_heater_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::water_heater_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->water_heater_json_(static_cast<water_heater::WaterHeater *>(source), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::water_heater_json_(water_heater::WaterHeater *obj, JsonDetail start_config) {
+std::string WebServer::water_heater_json_(water_heater::WaterHeater *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
   char buf[PSTR_LOCAL_SIZE];
@@ -1971,7 +1969,7 @@ void WebServer::handle_infrared_request(AsyncWebServerRequest *request, const Ur
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->infrared_json_(obj, detail);
+      std::string data = this->infrared_json_(obj, detail);
       request->send(200, ESPHOME_F("application/json"), data.c_str());
       return;
     }
@@ -2031,12 +2029,12 @@ void WebServer::handle_infrared_request(AsyncWebServerRequest *request, const Ur
   request->send(404);
 }
 
-json::SerializationBuffer<> WebServer::infrared_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::infrared_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->infrared_json_(static_cast<infrared::Infrared *>(source), DETAIL_ALL);
 }
 
-json::SerializationBuffer<> WebServer::infrared_json_(infrared::Infrared *obj, JsonDetail start_config) {
+std::string WebServer::infrared_json_(infrared::Infrared *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -2071,7 +2069,7 @@ void WebServer::handle_event_request(AsyncWebServerRequest *request, const UrlMa
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->event_json_(obj, StringRef(), detail);
+      std::string data = this->event_json_(obj, StringRef(), detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -2081,16 +2079,16 @@ void WebServer::handle_event_request(AsyncWebServerRequest *request, const UrlMa
 
 static StringRef get_event_type(event::Event *event) { return event ? event->get_last_event_type() : StringRef(); }
 
-json::SerializationBuffer<> WebServer::event_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::event_state_json_generator(WebServer *web_server, void *source) {
   auto *event = static_cast<event::Event *>(source);
   return web_server->event_json_(event, get_event_type(event), DETAIL_STATE);
 }
 // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-json::SerializationBuffer<> WebServer::event_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::event_all_json_generator(WebServer *web_server, void *source) {
   auto *event = static_cast<event::Event *>(source);
   return web_server->event_json_(event, get_event_type(event), DETAIL_ALL);
 }
-json::SerializationBuffer<> WebServer::event_json_(event::Event *obj, StringRef event_type, JsonDetail start_config) {
+std::string WebServer::event_json_(event::Event *obj, StringRef event_type, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -2124,7 +2122,7 @@ void WebServer::handle_update_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && entity_match.action_is_empty) {
       auto detail = get_request_detail(request);
-      auto data = this->update_json_(obj, detail);
+      std::string data = this->update_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -2140,15 +2138,15 @@ void WebServer::handle_update_request(AsyncWebServerRequest *request, const UrlM
   }
   request->send(404);
 }
-json::SerializationBuffer<> WebServer::update_state_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::update_state_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::update_all_json_generator(WebServer *web_server, void *source) {
+std::string WebServer::update_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_STATE);
 }
-json::SerializationBuffer<> WebServer::update_json_(update::UpdateEntity *obj, JsonDetail start_config) {
+std::string WebServer::update_json_(update::UpdateEntity *obj, JsonDetail start_config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   json::JsonBuilder builder;
   JsonObject root = builder.root();

esphome/components/web_server/web_server.h

@@ -2,7 +2,6 @@
 
 #include "list_entities.h"
 
-#include "esphome/components/json/json_util.h"
 #include "esphome/components/web_server_base/web_server_base.h"
 #ifdef USE_WEBSERVER
 #include "esphome/core/component.h"
@@ -104,7 +103,7 @@ enum JsonDetail { DETAIL_ALL, DETAIL_STATE };
   can be forgotten.
 */
 #if !defined(USE_ESP32) && defined(USE_ARDUINO)
-using message_generator_t = json::SerializationBuffer<>(WebServer *, void *);
+using message_generator_t = std::string(WebServer *, void *);
 
 class DeferredUpdateEventSourceList;
 class DeferredUpdateEventSource : public AsyncEventSource {
@@ -265,7 +264,7 @@ class WebServer : public Controller,
   void handle_index_request(AsyncWebServerRequest *request);
 
   /// Return the webserver configuration as JSON.
-  json::SerializationBuffer<> get_config_json();
+  std::string get_config_json();
 
 #ifdef USE_WEBSERVER_CSS_INCLUDE
   /// Handle included css request under '/0.css'.
@@ -287,8 +286,8 @@ class WebServer : public Controller,
   /// Handle a sensor request under '/sensor/<id>'.
   void handle_sensor_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> sensor_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> sensor_all_json_generator(WebServer *web_server, void *source);
+  static std::string sensor_state_json_generator(WebServer *web_server, void *source);
+  static std::string sensor_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_SWITCH
@@ -297,8 +296,8 @@ class WebServer : public Controller,
   /// Handle a switch request under '/switch/<id>/</turn_on/turn_off/toggle>'.
   void handle_switch_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> switch_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> switch_all_json_generator(WebServer *web_server, void *source);
+  static std::string switch_state_json_generator(WebServer *web_server, void *source);
+  static std::string switch_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_BUTTON
@@ -306,7 +305,7 @@ class WebServer : public Controller,
   void handle_button_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
   // Buttons are stateless, so there is no button_state_json_generator
-  static json::SerializationBuffer<> button_all_json_generator(WebServer *web_server, void *source);
+  static std::string button_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_BINARY_SENSOR
@@ -315,8 +314,8 @@ class WebServer : public Controller,
   /// Handle a binary sensor request under '/binary_sensor/<id>'.
   void handle_binary_sensor_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> binary_sensor_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> binary_sensor_all_json_generator(WebServer *web_server, void *source);
+  static std::string binary_sensor_state_json_generator(WebServer *web_server, void *source);
+  static std::string binary_sensor_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_FAN
@@ -325,8 +324,8 @@ class WebServer : public Controller,
   /// Handle a fan request under '/fan/<id>/</turn_on/turn_off/toggle>'.
   void handle_fan_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> fan_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> fan_all_json_generator(WebServer *web_server, void *source);
+  static std::string fan_state_json_generator(WebServer *web_server, void *source);
+  static std::string fan_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_LIGHT
@@ -335,8 +334,8 @@ class WebServer : public Controller,
   /// Handle a light request under '/light/<id>/</turn_on/turn_off/toggle>'.
   void handle_light_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> light_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> light_all_json_generator(WebServer *web_server, void *source);
+  static std::string light_state_json_generator(WebServer *web_server, void *source);
+  static std::string light_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_TEXT_SENSOR
@@ -345,8 +344,8 @@ class WebServer : public Controller,
   /// Handle a text sensor request under '/text_sensor/<id>'.
   void handle_text_sensor_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> text_sensor_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> text_sensor_all_json_generator(WebServer *web_server, void *source);
+  static std::string text_sensor_state_json_generator(WebServer *web_server, void *source);
+  static std::string text_sensor_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_COVER
@@ -355,8 +354,8 @@ class WebServer : public Controller,
   /// Handle a cover request under '/cover/<id>/<open/close/stop/set>'.
   void handle_cover_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> cover_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> cover_all_json_generator(WebServer *web_server, void *source);
+  static std::string cover_state_json_generator(WebServer *web_server, void *source);
+  static std::string cover_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_NUMBER
@@ -364,8 +363,8 @@ class WebServer : public Controller,
   /// Handle a number request under '/number/<id>'.
   void handle_number_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> number_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> number_all_json_generator(WebServer *web_server, void *source);
+  static std::string number_state_json_generator(WebServer *web_server, void *source);
+  static std::string number_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_DATETIME_DATE
@@ -373,8 +372,8 @@ class WebServer : public Controller,
   /// Handle a date request under '/date/<id>'.
   void handle_date_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> date_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> date_all_json_generator(WebServer *web_server, void *source);
+  static std::string date_state_json_generator(WebServer *web_server, void *source);
+  static std::string date_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_DATETIME_TIME
@@ -382,8 +381,8 @@ class WebServer : public Controller,
   /// Handle a time request under '/time/<id>'.
   void handle_time_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> time_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> time_all_json_generator(WebServer *web_server, void *source);
+  static std::string time_state_json_generator(WebServer *web_server, void *source);
+  static std::string time_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_DATETIME_DATETIME
@@ -391,8 +390,8 @@ class WebServer : public Controller,
   /// Handle a datetime request under '/datetime/<id>'.
   void handle_datetime_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> datetime_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> datetime_all_json_generator(WebServer *web_server, void *source);
+  static std::string datetime_state_json_generator(WebServer *web_server, void *source);
+  static std::string datetime_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_TEXT
@@ -400,8 +399,8 @@ class WebServer : public Controller,
   /// Handle a text input request under '/text/<id>'.
   void handle_text_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> text_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> text_all_json_generator(WebServer *web_server, void *source);
+  static std::string text_state_json_generator(WebServer *web_server, void *source);
+  static std::string text_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_SELECT
@@ -409,8 +408,8 @@ class WebServer : public Controller,
   /// Handle a select request under '/select/<id>'.
   void handle_select_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> select_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> select_all_json_generator(WebServer *web_server, void *source);
+  static std::string select_state_json_generator(WebServer *web_server, void *source);
+  static std::string select_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_CLIMATE
@@ -418,8 +417,8 @@ class WebServer : public Controller,
   /// Handle a climate request under '/climate/<id>'.
   void handle_climate_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> climate_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> climate_all_json_generator(WebServer *web_server, void *source);
+  static std::string climate_state_json_generator(WebServer *web_server, void *source);
+  static std::string climate_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_LOCK
@@ -428,8 +427,8 @@ class WebServer : public Controller,
   /// Handle a lock request under '/lock/<id>/</lock/unlock/open>'.
   void handle_lock_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> lock_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> lock_all_json_generator(WebServer *web_server, void *source);
+  static std::string lock_state_json_generator(WebServer *web_server, void *source);
+  static std::string lock_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_VALVE
@@ -438,8 +437,8 @@ class WebServer : public Controller,
   /// Handle a valve request under '/valve/<id>/<open/close/stop/set>'.
   void handle_valve_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> valve_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> valve_all_json_generator(WebServer *web_server, void *source);
+  static std::string valve_state_json_generator(WebServer *web_server, void *source);
+  static std::string valve_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_ALARM_CONTROL_PANEL
@@ -448,8 +447,8 @@ class WebServer : public Controller,
   /// Handle a alarm_control_panel request under '/alarm_control_panel/<id>'.
   void handle_alarm_control_panel_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> alarm_control_panel_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> alarm_control_panel_all_json_generator(WebServer *web_server, void *source);
+  static std::string alarm_control_panel_state_json_generator(WebServer *web_server, void *source);
+  static std::string alarm_control_panel_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_WATER_HEATER
@@ -458,22 +457,22 @@ class WebServer : public Controller,
   /// Handle a water_heater request under '/water_heater/<id>/<mode/set>'.
   void handle_water_heater_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> water_heater_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> water_heater_all_json_generator(WebServer *web_server, void *source);
+  static std::string water_heater_state_json_generator(WebServer *web_server, void *source);
+  static std::string water_heater_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_INFRARED
   /// Handle an infrared request under '/infrared/<id>/transmit'.
   void handle_infrared_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> infrared_all_json_generator(WebServer *web_server, void *source);
+  static std::string infrared_all_json_generator(WebServer *web_server, void *source);
 #endif
 
 #ifdef USE_EVENT
   void on_event(event::Event *obj) override;
 
-  static json::SerializationBuffer<> event_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> event_all_json_generator(WebServer *web_server, void *source);
+  static std::string event_state_json_generator(WebServer *web_server, void *source);
+  static std::string event_all_json_generator(WebServer *web_server, void *source);
 
   /// Handle a event request under '/event<id>'.
   void handle_event_request(AsyncWebServerRequest *request, const UrlMatch &match);
@@ -485,8 +484,8 @@ class WebServer : public Controller,
   /// Handle a update request under '/update/<id>'.
   void handle_update_request(AsyncWebServerRequest *request, const UrlMatch &match);
 
-  static json::SerializationBuffer<> update_state_json_generator(WebServer *web_server, void *source);
-  static json::SerializationBuffer<> update_all_json_generator(WebServer *web_server, void *source);
+  static std::string update_state_json_generator(WebServer *web_server, void *source);
+  static std::string update_all_json_generator(WebServer *web_server, void *source);
 #endif
 
   /// Override the web handler's canHandle method.
@@ -594,74 +593,71 @@ class WebServer : public Controller,
 
  private:
 #ifdef USE_SENSOR
-  json::SerializationBuffer<> sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config);
+  std::string sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config);
 #endif
 #ifdef USE_SWITCH
-  json::SerializationBuffer<> switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config);
+  std::string switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config);
 #endif
 #ifdef USE_BUTTON
-  json::SerializationBuffer<> button_json_(button::Button *obj, JsonDetail start_config);
+  std::string button_json_(button::Button *obj, JsonDetail start_config);
 #endif
 #ifdef USE_BINARY_SENSOR
-  json::SerializationBuffer<> binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value,
-                                                  JsonDetail start_config);
+  std::string binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config);
 #endif
 #ifdef USE_FAN
-  json::SerializationBuffer<> fan_json_(fan::Fan *obj, JsonDetail start_config);
+  std::string fan_json_(fan::Fan *obj, JsonDetail start_config);
 #endif
 #ifdef USE_LIGHT
-  json::SerializationBuffer<> light_json_(light::LightState *obj, JsonDetail start_config);
+  std::string light_json_(light::LightState *obj, JsonDetail start_config);
 #endif
 #ifdef USE_TEXT_SENSOR
-  json::SerializationBuffer<> text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value,
-                                                JsonDetail start_config);
+  std::string text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value, JsonDetail start_config);
 #endif
 #ifdef USE_COVER
-  json::SerializationBuffer<> cover_json_(cover::Cover *obj, JsonDetail start_config);
+  std::string cover_json_(cover::Cover *obj, JsonDetail start_config);
 #endif
 #ifdef USE_NUMBER
-  json::SerializationBuffer<> number_json_(number::Number *obj, float value, JsonDetail start_config);
+  std::string number_json_(number::Number *obj, float value, JsonDetail start_config);
 #endif
 #ifdef USE_DATETIME_DATE
-  json::SerializationBuffer<> date_json_(datetime::DateEntity *obj, JsonDetail start_config);
+  std::string date_json_(datetime::DateEntity *obj, JsonDetail start_config);
 #endif
 #ifdef USE_DATETIME_TIME
-  json::SerializationBuffer<> time_json_(datetime::TimeEntity *obj, JsonDetail start_config);
+  std::string time_json_(datetime::TimeEntity *obj, JsonDetail start_config);
 #endif
 #ifdef USE_DATETIME_DATETIME
-  json::SerializationBuffer<> datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config);
+  std::string datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config);
 #endif
 #ifdef USE_TEXT
-  json::SerializationBuffer<> text_json_(text::Text *obj, const std::string &value, JsonDetail start_config);
+  std::string text_json_(text::Text *obj, const std::string &value, JsonDetail start_config);
 #endif
 #ifdef USE_SELECT
-  json::SerializationBuffer<> select_json_(select::Select *obj, StringRef value, JsonDetail start_config);
+  std::string select_json_(select::Select *obj, StringRef value, JsonDetail start_config);
 #endif
 #ifdef USE_CLIMATE
-  json::SerializationBuffer<> climate_json_(climate::Climate *obj, JsonDetail start_config);
+  std::string climate_json_(climate::Climate *obj, JsonDetail start_config);
 #endif
 #ifdef USE_LOCK
-  json::SerializationBuffer<> lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config);
+  std::string lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config);
 #endif
 #ifdef USE_VALVE
-  json::SerializationBuffer<> valve_json_(valve::Valve *obj, JsonDetail start_config);
+  std::string valve_json_(valve::Valve *obj, JsonDetail start_config);
 #endif
 #ifdef USE_ALARM_CONTROL_PANEL
-  json::SerializationBuffer<> alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
-                                                        alarm_control_panel::AlarmControlPanelState value,
-                                                        JsonDetail start_config);
+  std::string alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
+                                        alarm_control_panel::AlarmControlPanelState value, JsonDetail start_config);
 #endif
 #ifdef USE_EVENT
-  json::SerializationBuffer<> event_json_(event::Event *obj, StringRef event_type, JsonDetail start_config);
+  std::string event_json_(event::Event *obj, StringRef event_type, JsonDetail start_config);
 #endif
 #ifdef USE_WATER_HEATER
-  json::SerializationBuffer<> water_heater_json_(water_heater::WaterHeater *obj, JsonDetail start_config);
+  std::string water_heater_json_(water_heater::WaterHeater *obj, JsonDetail start_config);
 #endif
 #ifdef USE_INFRARED
-  json::SerializationBuffer<> infrared_json_(infrared::Infrared *obj, JsonDetail start_config);
+  std::string infrared_json_(infrared::Infrared *obj, JsonDetail start_config);
 #endif
 #ifdef USE_UPDATE
-  json::SerializationBuffer<> update_json_(update::UpdateEntity *obj, JsonDetail start_config);
+  std::string update_json_(update::UpdateEntity *obj, JsonDetail start_config);
 #endif
 };
 

esphome/components/web_server_base/web_server_base.cpp

@@ -11,7 +11,7 @@ static const char *const TAG = "web_server_base";
 
 WebServerBase *global_web_server_base = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-void __attribute__((flatten)) WebServerBase::add_handler(AsyncWebHandler *handler) {
+void WebServerBase::add_handler(AsyncWebHandler *handler) {
   // remove all handlers
 
 #ifdef USE_WEBSERVER_AUTH

esphome/components/web_server_idf/web_server_idf.cpp

@@ -457,9 +457,8 @@ void AsyncWebServerResponse::addHeader(const char *name, const char *value) {
 void AsyncResponseStream::print(float value) {
   // Use stack buffer to avoid temporary string allocation
   // Size: sign (1) + digits (10) + decimal (1) + precision (6) + exponent (5) + null (1) = 24, use 32 for safety
-  constexpr size_t float_buf_size = 32;
-  char buf[float_buf_size];
-  int len = snprintf(buf, float_buf_size, "%f", value);
+  char buf[32];
+  int len = snprintf(buf, sizeof(buf), "%f", value);
   this->content_.append(buf, len);
 }
 
@@ -564,7 +563,7 @@ AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *
 
   // Configure reconnect timeout and send config
   // this should always go through since the tcp send buffer is empty on connect
-  auto message = ws->get_config_json();
+  std::string message = ws->get_config_json();
   this->try_send_nodefer(message.c_str(), "ping", millis(), 30000);
 
 #ifdef USE_WEBSERVER_SORTING
@@ -618,7 +617,7 @@ void AsyncEventSourceResponse::deq_push_back_with_dedup_(void *source, message_g
 void AsyncEventSourceResponse::process_deferred_queue_() {
   while (!deferred_queue_.empty()) {
     DeferredEvent &de = deferred_queue_.front();
-    auto message = de.message_generator_(web_server_, de.source_);
+    std::string message = de.message_generator_(web_server_, de.source_);
     if (this->try_send_nodefer(message.c_str(), "state")) {
       // O(n) but memory efficiency is more important than speed here which is why std::vector was chosen
       deferred_queue_.erase(deferred_queue_.begin());
@@ -855,7 +854,7 @@ void AsyncEventSourceResponse::deferrable_send_state(void *source, const char *e
     // trying to send first
     deq_push_back_with_dedup_(source, message_generator);
   } else {
-    auto message = message_generator(web_server_, source);
+    std::string message = message_generator(web_server_, source);
     if (!this->try_send_nodefer(message.c_str(), "state")) {
       deq_push_back_with_dedup_(source, message_generator);
     }

esphome/components/web_server_idf/web_server_idf.h

@@ -16,7 +16,6 @@
 #include <vector>
 
 #ifdef USE_WEBSERVER
-#include "esphome/components/json/json_util.h"
 #include "esphome/components/web_server/list_entities.h"
 #endif
 
@@ -251,7 +250,7 @@ class AsyncWebHandler {
 class AsyncEventSource;
 class AsyncEventSourceResponse;
 
-using message_generator_t = json::SerializationBuffer<>(esphome::web_server::WebServer *, void *);
+using message_generator_t = std::string(esphome::web_server::WebServer *, void *);
 
 /*
   This class holds a pointer to the source component that wants to publish a state event, and a pointer to a function

esphome/components/wifi/wifi_component.cpp

@@ -3,7 +3,6 @@
 #include <cassert>
 #include <cinttypes>
 #include <cmath>
-#include <type_traits>
 
 #ifdef USE_ESP32
 #if (ESP_IDF_VERSION_MAJOR >= 5 && ESP_IDF_VERSION_MINOR >= 1)
@@ -719,7 +718,7 @@ void WiFiComponent::restart_adapter() {
   // through start_connecting() first. Without this clear, stale errors would
   // trigger spurious "failed (callback)" logs. The canonical clear location
   // is in start_connecting(); this is the only exception to that pattern.
-  this->error_from_callback_ = 0;
+  this->error_from_callback_ = false;
 }
 
 void WiFiComponent::loop() {
@@ -1149,7 +1148,7 @@ void WiFiComponent::start_connecting(const WiFiAP &ap) {
   // This is the canonical location for clearing the flag since all connection
   // attempts go through start_connecting(). The only other clear is in
   // restart_adapter() which enters COOLDOWN without calling start_connecting().
-  this->error_from_callback_ = 0;
+  this->error_from_callback_ = false;
 
   if (!this->wifi_sta_connect_(ap)) {
     ESP_LOGE(TAG, "wifi_sta_connect_ failed");
@@ -1333,61 +1332,20 @@ void WiFiComponent::start_scanning() {
 // Using insertion sort instead of std::stable_sort saves flash memory
 // by avoiding template instantiations (std::rotate, std::stable_sort, lambdas)
 // IMPORTANT: This sort is stable (preserves relative order of equal elements)
-//
-// Uses raw memcpy instead of copy assignment to avoid CompactString's
-// destructor/constructor overhead (heap delete[]/new[] for long SSIDs).
-// Copy assignment calls ~CompactString() then placement-new for every shift,
-// which means delete[]/new[] per shift for heap-allocated SSIDs. With 70+
-// networks (e.g., captive portal showing full scan results), this caused
-// event loop blocking from hundreds of heap operations in a tight loop.
-//
-// This is safe because we're permuting elements within the same array —
-// each slot is overwritten exactly once, so no ownership duplication occurs.
-// All members of WiFiScanResult are either trivially copyable (bssid, channel,
-// rssi, priority, flags) or CompactString, which stores either inline data or
-// a heap pointer — never a self-referential pointer (unlike std::string's SSO
-// on some implementations). This was not possible before PR#13472 replaced
-// std::string with CompactString, since std::string's internal layout is
-// implementation-defined and may use self-referential pointers.
-//
-// TODO: If C++ standardizes std::trivially_relocatable, add the assertion for
-// WiFiScanResult/CompactString here to formally express the memcpy safety guarantee.
 template<typename VectorType> static void insertion_sort_scan_results(VectorType &results) {
-  // memcpy-based sort requires no self-referential pointers or virtual dispatch.
-  // These static_asserts guard the assumptions. If any fire, the memcpy sort
-  // must be reviewed for safety before updating the expected values.
-  //
-  // No vtable pointers (memcpy would corrupt vptr)
-  static_assert(!std::is_polymorphic<WiFiScanResult>::value, "WiFiScanResult must not have vtable");
-  static_assert(!std::is_polymorphic<CompactString>::value, "CompactString must not have vtable");
-  // Standard layout ensures predictable memory layout with no virtual bases
-  // and no mixed-access-specifier reordering
-  static_assert(std::is_standard_layout<WiFiScanResult>::value, "WiFiScanResult must be standard layout");
-  static_assert(std::is_standard_layout<CompactString>::value, "CompactString must be standard layout");
-  // Size checks catch added/removed fields that may need safety review
-  static_assert(sizeof(WiFiScanResult) == 32, "WiFiScanResult size changed - verify memcpy sort is still safe");
-  static_assert(sizeof(CompactString) == 20, "CompactString size changed - verify memcpy sort is still safe");
-  // Alignment must match for reinterpret_cast of key_buf to be valid
-  static_assert(alignof(WiFiScanResult) <= alignof(std::max_align_t), "WiFiScanResult alignment exceeds max_align_t");
   const size_t size = results.size();
-  constexpr size_t elem_size = sizeof(WiFiScanResult);
-  // Suppress warnings for intentional memcpy on non-trivially-copyable type.
-  // Safety is guaranteed by the static_asserts above and the permutation invariant.
-  // NOLINTNEXTLINE(bugprone-undefined-memory-manipulation)
-  auto *memcpy_fn = &memcpy;
   for (size_t i = 1; i < size; i++) {
-    alignas(WiFiScanResult) uint8_t key_buf[elem_size];
-    memcpy_fn(key_buf, &results[i], elem_size);
-    const auto &key = *reinterpret_cast<const WiFiScanResult *>(key_buf);
+    // Make a copy to avoid issues with move semantics during comparison
+    WiFiScanResult key = results[i];
     int32_t j = i - 1;
 
     // Move elements that are worse than key to the right
     // For stability, we only move if key is strictly better than results[j]
     while (j >= 0 && wifi_scan_result_is_better(key, results[j])) {
-      memcpy_fn(&results[j + 1], &results[j], elem_size);
+      results[j + 1] = results[j];
       j--;
     }
-    memcpy_fn(&results[j + 1], key_buf, elem_size);
+    results[j + 1] = key;
   }
 }
 
@@ -1969,7 +1927,6 @@ void WiFiComponent::log_and_adjust_priority_for_failed_connect_() {
         (old_priority > std::numeric_limits<int8_t>::min()) ? (old_priority - 1) : std::numeric_limits<int8_t>::min();
     this->set_sta_priority(failed_bssid.value(), new_priority);
   }
-
   char bssid_s[18];
   format_mac_addr_upper(failed_bssid.value().data(), bssid_s);
   ESP_LOGD(TAG, "Failed " LOG_SECRET("'%s'") " " LOG_SECRET("(%s)") ", priority %d → %d", ssid != nullptr ? ssid : "",

esphome/components/wifi/wifi_component.h

@@ -10,7 +10,6 @@
 
 #include <span>
 #include <string>
-#include <type_traits>
 #include <vector>
 
 #ifdef USE_LIBRETINY
@@ -220,14 +219,6 @@ class CompactString {
 };
 
 static_assert(sizeof(CompactString) == 20, "CompactString must be exactly 20 bytes");
-// CompactString is not trivially copyable (non-trivial destructor/copy for heap case).
-// However, its layout has no self-referential pointers: storage_[] contains either inline
-// data or an external heap pointer — never a pointer to itself. This is unlike libstdc++
-// std::string SSO where _M_p points to _M_local_buf within the same object.
-// This property allows memcpy-based permutation sorting where each element ends up in
-// exactly one slot (no ownership duplication). These asserts document that layout property.
-static_assert(std::is_standard_layout<CompactString>::value, "CompactString must be standard layout");
-static_assert(!std::is_polymorphic<CompactString>::value, "CompactString must not have vtable");
 
 class WiFiAP {
   friend class WiFiComponent;

esphome/components/wifi/wifi_component_esp8266.cpp

@@ -224,8 +224,14 @@ bool WiFiComponent::wifi_apply_hostname_() {
 #else
     intf->hostname = wifi_station_get_hostname();
 #endif
-    if (netif_dhcp_data(intf) != nullptr) {
-      // renew already started DHCP leases
+    if (netif_dhcp_data(intf) != nullptr && netif_is_link_up(intf)) {
+      // Renew already started DHCP leases to inform server of hostname change.
+      // Only attempt when the interface has link — calling dhcp_renew() without
+      // an active connection corrupts lwIP's DHCP state machine (it unconditionally
+      // sets state to RENEWING before attempting to send, and never rolls back on
+      // failure). This causes dhcp_network_changed() to call dhcp_reboot() instead
+      // of dhcp_discover() when WiFi later connects, sending a bogus DHCP REQUEST
+      // for IP 0.0.0.0 that can put some routers into a persistent bad state.
       err_t lwipret = dhcp_renew(intf);
       if (lwipret != ERR_OK) {
         ESP_LOGW(TAG, "wifi_apply_hostname_(%s): lwIP error %d on interface %c%c (index %d)", intf->hostname,

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -775,7 +775,7 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     }
     s_sta_connected = false;
     s_sta_connecting = false;
-    error_from_callback_ = 1;
+    error_from_callback_ = true;
 #ifdef USE_WIFI_CONNECT_STATE_LISTENERS
     this->notify_disconnect_state_listeners_();
 #endif

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -495,7 +495,7 @@ void WiFiComponent::wifi_process_event_(LTWiFiEvent *event) {
                    s_ignored_disconnect_count, get_disconnect_reason_str(it.reason));
           s_sta_state = LTWiFiSTAState::ERROR_FAILED;
           WiFi.disconnect();
-          this->error_from_callback_ = 1;
+          this->error_from_callback_ = true;
           // Don't break - fall through to notify listeners
         } else {
           ESP_LOGV(TAG, "Ignoring disconnect event with empty ssid while connecting (reason=%s, count=%u)",
@@ -521,7 +521,7 @@ void WiFiComponent::wifi_process_event_(LTWiFiEvent *event) {
           reason == WIFI_REASON_NO_AP_FOUND || reason == WIFI_REASON_ASSOC_FAIL ||
           reason == WIFI_REASON_HANDSHAKE_TIMEOUT) {
         WiFi.disconnect();
-        this->error_from_callback_ = 1;
+        this->error_from_callback_ = true;
       }
 
 #ifdef USE_WIFI_CONNECT_STATE_LISTENERS
@@ -537,7 +537,7 @@ void WiFiComponent::wifi_process_event_(LTWiFiEvent *event) {
       if (it.old_mode != WIFI_AUTH_OPEN && it.new_mode == WIFI_AUTH_OPEN) {
         ESP_LOGW(TAG, "Potential Authmode downgrade detected, disconnecting");
         WiFi.disconnect();
-        this->error_from_callback_ = 1;
+        this->error_from_callback_ = true;
         s_sta_state = LTWiFiSTAState::ERROR_FAILED;
       }
       break;

esphome/core/__init__.py

@@ -766,15 +766,6 @@ class EsphomeCore:
     def relative_piolibdeps_path(self, *path: str | Path) -> Path:
         return self.relative_build_path(".piolibdeps", *path)
 
-    @property
-    def platformio_cache_dir(self) -> str:
-        """Get the PlatformIO cache directory path."""
-        # Check if running in Docker/HA addon with custom cache dir
-        if (cache_dir := os.environ.get("PLATFORMIO_CACHE_DIR")) and cache_dir.strip():
-            return cache_dir
-        # Default PlatformIO cache location
-        return os.path.expanduser("~/.platformio/.cache")
-
     @property
     def firmware_bin(self) -> Path:
         # Check if using native ESP-IDF build (--native-idf)

esphome/core/automation.h

@@ -4,7 +4,6 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/preferences.h"
-#include "esphome/core/progmem.h"
 #include "esphome/core/string_ref.h"
 #include <concepts>
 #include <functional>
@@ -57,16 +56,6 @@ template<typename T, typename... X> class TemplatableValue {
     this->static_str_ = str;
   }
 
-#ifdef USE_ESP8266
-  // On ESP8266, __FlashStringHelper* is a distinct type from const char*.
-  // ESPHOME_F(s) expands to F(s) which returns __FlashStringHelper* pointing to PROGMEM.
-  // Store as FLASH_STRING — value()/is_empty()/ref_or_copy_to() use _P functions
-  // to access the PROGMEM pointer safely.
-  TemplatableValue(const __FlashStringHelper *str) requires std::same_as<T, std::string> : type_(FLASH_STRING) {
-    this->static_str_ = reinterpret_cast<const char *>(str);
-  }
-#endif
-
   template<typename F> TemplatableValue(F value) requires(!std::invocable<F, X...>) : type_(VALUE) {
     if constexpr (USE_HEAP_STORAGE) {
       this->value_ = new T(std::move(value));
@@ -100,7 +89,7 @@ template<typename T, typename... X> class TemplatableValue {
       this->f_ = new std::function<T(X...)>(*other.f_);
     } else if (this->type_ == STATELESS_LAMBDA) {
       this->stateless_f_ = other.stateless_f_;
-    } else if (this->type_ == STATIC_STRING || this->type_ == FLASH_STRING) {
+    } else if (this->type_ == STATIC_STRING) {
       this->static_str_ = other.static_str_;
     }
   }
@@ -119,7 +108,7 @@ template<typename T, typename... X> class TemplatableValue {
       other.f_ = nullptr;
     } else if (this->type_ == STATELESS_LAMBDA) {
       this->stateless_f_ = other.stateless_f_;
-    } else if (this->type_ == STATIC_STRING || this->type_ == FLASH_STRING) {
+    } else if (this->type_ == STATIC_STRING) {
       this->static_str_ = other.static_str_;
     }
     other.type_ = NONE;
@@ -152,7 +141,7 @@ template<typename T, typename... X> class TemplatableValue {
     } else if (this->type_ == LAMBDA) {
       delete this->f_;
     }
-    // STATELESS_LAMBDA/STATIC_STRING/FLASH_STRING/NONE: no cleanup needed (pointers, not heap-allocated)
+    // STATELESS_LAMBDA/STATIC_STRING/NONE: no cleanup needed (pointers, not heap-allocated)
   }
 
   bool has_value() const { return this->type_ != NONE; }
@@ -176,17 +165,6 @@ template<typename T, typename... X> class TemplatableValue {
           return std::string(this->static_str_);
         }
         __builtin_unreachable();
-#ifdef USE_ESP8266
-      case FLASH_STRING:
-        // PROGMEM pointer — must use _P functions to access on ESP8266
-        if constexpr (std::same_as<T, std::string>) {
-          size_t len = strlen_P(this->static_str_);
-          std::string result(len, '\0');
-          memcpy_P(result.data(), this->static_str_, len);
-          return result;
-        }
-        __builtin_unreachable();
-#endif
       case NONE:
       default:
         return T{};
@@ -208,12 +186,9 @@ template<typename T, typename... X> class TemplatableValue {
   }
 
   /// Check if this holds a static string (const char* stored without allocation)
-  /// The pointer is always directly readable (RAM or flash-mapped).
-  /// Returns false for FLASH_STRING (PROGMEM on ESP8266, requires _P functions).
   bool is_static_string() const { return this->type_ == STATIC_STRING; }
 
   /// Get the static string pointer (only valid if is_static_string() returns true)
-  /// The pointer is always directly readable — FLASH_STRING uses a separate type.
   const char *get_static_string() const { return this->static_str_; }
 
   /// Check if the string value is empty without allocating (for std::string specialization).
@@ -225,12 +200,6 @@ template<typename T, typename... X> class TemplatableValue {
         return true;
       case STATIC_STRING:
         return this->static_str_ == nullptr || this->static_str_[0] == '\0';
-#ifdef USE_ESP8266
-      case FLASH_STRING:
-        // PROGMEM pointer — must use progmem_read_byte on ESP8266
-        return this->static_str_ == nullptr ||
-               progmem_read_byte(reinterpret_cast<const uint8_t *>(this->static_str_)) == '\0';
-#endif
       case VALUE:
         return this->value_->empty();
       default:  // LAMBDA/STATELESS_LAMBDA - must call value()
@@ -240,9 +209,8 @@ template<typename T, typename... X> class TemplatableValue {
 
   /// Get a StringRef to the string value without heap allocation when possible.
   /// For STATIC_STRING/VALUE, returns reference to existing data (no allocation).
-  /// For FLASH_STRING (ESP8266 PROGMEM), copies to provided buffer via _P functions.
   /// For LAMBDA/STATELESS_LAMBDA, calls value(), copies to provided buffer, returns ref to buffer.
-  /// @param lambda_buf Buffer used only for copy cases (must remain valid while StringRef is used).
+  /// @param lambda_buf Buffer used only for lambda case (must remain valid while StringRef is used).
   /// @param lambda_buf_size Size of the buffer.
   /// @return StringRef pointing to the string data.
   StringRef ref_or_copy_to(char *lambda_buf, size_t lambda_buf_size) const requires std::same_as<T, std::string> {
@@ -253,19 +221,6 @@ template<typename T, typename... X> class TemplatableValue {
         if (this->static_str_ == nullptr)
           return StringRef();
         return StringRef(this->static_str_, strlen(this->static_str_));
-#ifdef USE_ESP8266
-      case FLASH_STRING:
-        if (this->static_str_ == nullptr)
-          return StringRef();
-        {
-          // PROGMEM pointer — copy to buffer via _P functions
-          size_t len = strlen_P(this->static_str_);
-          size_t copy_len = std::min(len, lambda_buf_size - 1);
-          memcpy_P(lambda_buf, this->static_str_, copy_len);
-          lambda_buf[copy_len] = '\0';
-          return StringRef(lambda_buf, copy_len);
-        }
-#endif
       case VALUE:
         return StringRef(this->value_->data(), this->value_->size());
       default: {  // LAMBDA/STATELESS_LAMBDA - must call value() and copy
@@ -284,7 +239,6 @@ template<typename T, typename... X> class TemplatableValue {
    LAMBDA,
    STATELESS_LAMBDA,
    STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
-   FLASH_STRING,   // PROGMEM pointer on ESP8266; never set on other platforms
  } type_;
   // For std::string, use heap pointer to minimize union size (4 bytes vs 12+).
   // For other types, store value inline as before.
@@ -293,7 +247,7 @@ template<typename T, typename... X> class TemplatableValue {
     ValueStorage value_;  // T for inline storage, T* for heap storage
     std::function<T(X...)> *f_;
     T (*stateless_f_)(X...);
-    const char *static_str_;  // For STATIC_STRING and FLASH_STRING types
+    const char *static_str_;  // For STATIC_STRING type
   };
 };
 

esphome/core/defines.h

@@ -148,9 +148,9 @@
 #define USE_MQTT
 #define USE_MQTT_COVER_JSON
 #define USE_NETWORK
-#define USE_ONLINE_IMAGE_BMP_SUPPORT
-#define USE_ONLINE_IMAGE_PNG_SUPPORT
-#define USE_ONLINE_IMAGE_JPEG_SUPPORT
+#define USE_RUNTIME_IMAGE_BMP
+#define USE_RUNTIME_IMAGE_PNG
+#define USE_RUNTIME_IMAGE_JPEG
 #define USE_OTA
 #define USE_OTA_PASSWORD
 #define USE_OTA_STATE_LISTENER

esphome/core/entity_base.cpp

@@ -152,13 +152,11 @@ void EntityBase_UnitOfMeasurement::set_unit_of_measurement(const char *unit_of_m
   this->unit_of_measurement_ = unit_of_measurement;
 }
 
-#ifdef USE_ENTITY_ICON
 void log_entity_icon(const char *tag, const char *prefix, const EntityBase &obj) {
   if (!obj.get_icon_ref().empty()) {
     ESP_LOGCONFIG(tag, "%s  Icon: '%s'", prefix, obj.get_icon_ref().c_str());
   }
 }
-#endif
 
 void log_entity_device_class(const char *tag, const char *prefix, const EntityBase_DeviceClass &obj) {
   if (!obj.get_device_class_ref().empty()) {

esphome/core/entity_base.h

@@ -231,12 +231,8 @@ class EntityBase_UnitOfMeasurement {  // NOLINT(readability-identifier-naming)
 };
 
 /// Log entity icon if set (for use in dump_config)
-#ifdef USE_ENTITY_ICON
 #define LOG_ENTITY_ICON(tag, prefix, obj) log_entity_icon(tag, prefix, obj)
 void log_entity_icon(const char *tag, const char *prefix, const EntityBase &obj);
-#else
-#define LOG_ENTITY_ICON(tag, prefix, obj)
-#endif
 /// Log entity device class if set (for use in dump_config)
 #define LOG_ENTITY_DEVICE_CLASS(tag, prefix, obj) log_entity_device_class(tag, prefix, obj)
 void log_entity_device_class(const char *tag, const char *prefix, const EntityBase_DeviceClass &obj);

esphome/core/helpers.cpp

@@ -348,10 +348,7 @@ std::string format_hex(const uint8_t *data, size_t length) {
   format_hex_to(&ret[0], length * 2 + 1, data, length);
   return ret;
 }
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 std::string format_hex(const std::vector<uint8_t> &data) { return format_hex(data.data(), data.size()); }
-#pragma GCC diagnostic pop
 
 char *format_hex_pretty_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length, char separator) {
   return format_hex_internal(buffer, buffer_size, data, length, separator, 'A');
@@ -520,8 +517,10 @@ int8_t step_to_accuracy_decimals(float step) {
   return str.length() - dot_pos - 1;
 }
 
-// Store BASE64 characters as array - automatically placed in flash/ROM on embedded platforms
-static const char BASE64_CHARS[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+// Use C-style string constant to store in ROM instead of RAM (saves 24 bytes)
+static constexpr const char *BASE64_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                            "abcdefghijklmnopqrstuvwxyz"
+                                            "0123456789+/";
 
 // Helper function to find the index of a base64/base64url character in the lookup table.
 // Returns the character's position (0-63) if found, or 0 if not found.

esphome/core/helpers.h

@@ -133,78 +133,6 @@ template<typename T> class ConstVector {
   size_t size_;
 };
 
-/// Small buffer optimization - stores data inline when small, heap-allocates for large data
-/// This avoids heap fragmentation for common small allocations while supporting arbitrary sizes.
-/// Memory management is encapsulated - callers just use set() and data().
-template<size_t InlineSize = 8> class SmallInlineBuffer {
- public:
-  SmallInlineBuffer() = default;
-  ~SmallInlineBuffer() {
-    if (!this->is_inline_())
-      delete[] this->heap_;
-  }
-
-  // Move constructor
-  SmallInlineBuffer(SmallInlineBuffer &&other) noexcept : len_(other.len_) {
-    if (other.is_inline_()) {
-      memcpy(this->inline_, other.inline_, this->len_);
-    } else {
-      this->heap_ = other.heap_;
-      other.heap_ = nullptr;
-    }
-    other.len_ = 0;
-  }
-
-  // Move assignment
-  SmallInlineBuffer &operator=(SmallInlineBuffer &&other) noexcept {
-    if (this != &other) {
-      if (!this->is_inline_())
-        delete[] this->heap_;
-      this->len_ = other.len_;
-      if (other.is_inline_()) {
-        memcpy(this->inline_, other.inline_, this->len_);
-      } else {
-        this->heap_ = other.heap_;
-        other.heap_ = nullptr;
-      }
-      other.len_ = 0;
-    }
-    return *this;
-  }
-
-  // Disable copy (would need deep copy of heap data)
-  SmallInlineBuffer(const SmallInlineBuffer &) = delete;
-  SmallInlineBuffer &operator=(const SmallInlineBuffer &) = delete;
-
-  /// Set buffer contents, allocating heap if needed
-  void set(const uint8_t *src, size_t size) {
-    // Free existing heap allocation if switching from heap to inline or different heap size
-    if (!this->is_inline_() && (size <= InlineSize || size != this->len_)) {
-      delete[] this->heap_;
-      this->heap_ = nullptr;  // Defensive: prevent use-after-free if logic changes
-    }
-    // Allocate new heap buffer if needed
-    if (size > InlineSize && (this->is_inline_() || size != this->len_)) {
-      this->heap_ = new uint8_t[size];  // NOLINT(cppcoreguidelines-owning-memory)
-    }
-    this->len_ = size;
-    memcpy(this->data(), src, size);
-  }
-
-  uint8_t *data() { return this->is_inline_() ? this->inline_ : this->heap_; }
-  const uint8_t *data() const { return this->is_inline_() ? this->inline_ : this->heap_; }
-  size_t size() const { return this->len_; }
-
- protected:
-  bool is_inline_() const { return this->len_ <= InlineSize; }
-
-  size_t len_{0};
-  union {
-    uint8_t inline_[InlineSize]{};  // Zero-init ensures clean initial state
-    uint8_t *heap_;
-  };
-};
-
 /// Minimal static vector - saves memory by avoiding std::vector overhead
 template<typename T, size_t N> class StaticVector {
  public:
@@ -269,9 +197,6 @@ template<typename T, size_t N> class StaticVector {
   size_t size() const { return count_; }
   bool empty() const { return count_ == 0; }
 
-  // Direct access to size counter for efficient in-place construction
-  size_t &count() { return count_; }
-
   // Direct access to underlying data
   T *data() { return data_.data(); }
   const T *data() const { return data_.data(); }
@@ -1143,17 +1068,13 @@ std::string format_hex(const std::vector<uint8_t> &data);
 /// Causes heap fragmentation on long-running devices.
 template<typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0> std::string format_hex(T val) {
   val = convert_big_endian(val);
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   return format_hex(reinterpret_cast<uint8_t *>(&val), sizeof(T));
-#pragma GCC diagnostic pop
 }
 /// Format the std::array \p data in lowercased hex.
 /// @warning Allocates heap memory. Use format_hex_to() with a stack buffer instead.
 /// Causes heap fragmentation on long-running devices.
 template<std::size_t N> std::string format_hex(const std::array<uint8_t, N> &data) {
   return format_hex(data.data(), data.size());
-#pragma GCC diagnostic pop
 }
 
 /** Format a byte array in pretty-printed, human-readable hex format.

esphome/core/scheduler.h

@@ -149,9 +149,10 @@ class Scheduler {
     } name_;
     uint32_t interval;
     // Split time to handle millis() rollover. The scheduler combines the 32-bit millis()
-    // with a 16-bit rollover counter to create a 48-bit time space (stored as 64-bit
-    // for compatibility). With 49.7 days per 32-bit rollover, the 16-bit counter
-    // supports 49.7 days × 65536 = ~8900 years. This ensures correct scheduling
+    // with a 16-bit rollover counter to create a 48-bit time space (using 32+16 bits).
+    // This is intentionally limited to 48 bits, not stored as a full 64-bit value.
+    // With 49.7 days per 32-bit rollover, the 16-bit counter supports
+    // 49.7 days × 65536 = ~8900 years. This ensures correct scheduling
     // even when devices run for months. Split into two fields for better memory
     // alignment on 32-bit systems.
     uint32_t next_execution_low_;  // Lower 32 bits of execution time (millis value)

esphome/core/time.cpp

@@ -2,6 +2,7 @@
 #include "helpers.h"
 
 #include <algorithm>
+#include <cinttypes>
 
 namespace esphome {
 
@@ -66,121 +67,56 @@ std::string ESPTime::strftime(const char *format) {
 
 std::string ESPTime::strftime(const std::string &format) { return this->strftime(format.c_str()); }
 
-// Helper to parse exactly N digits, returns false if not enough digits
-static bool parse_digits(const char *&p, const char *end, int count, uint16_t &value) {
-  value = 0;
-  for (int i = 0; i < count; i++) {
-    if (p >= end || *p < '0' || *p > '9')
-      return false;
-    value = value * 10 + (*p - '0');
-    p++;
-  }
-  return true;
-}
-
-// Helper to check for expected character
-static bool expect_char(const char *&p, const char *end, char expected) {
-  if (p >= end || *p != expected)
-    return false;
-  p++;
-  return true;
-}
-
 bool ESPTime::strptime(const char *time_to_parse, size_t len, ESPTime &esp_time) {
-  // Supported formats:
-  //   YYYY-MM-DD HH:MM:SS (19 chars)
-  //   YYYY-MM-DD HH:MM    (16 chars)
-  //   YYYY-MM-DD          (10 chars)
-  //   HH:MM:SS            (8 chars)
-  //   HH:MM               (5 chars)
+  uint16_t year;
+  uint8_t month;
+  uint8_t day;
+  uint8_t hour;
+  uint8_t minute;
+  uint8_t second;
+  int num;
+  const int ilen = static_cast<int>(len);
 
-  if (time_to_parse == nullptr || len == 0)
+  if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+             &hour,                                                                              // NOLINT
+             &minute,                                                                            // NOLINT
+             &second, &num) == 6 &&                                                              // NOLINT
+      num == ilen) {
+    esp_time.year = year;
+    esp_time.month = month;
+    esp_time.day_of_month = day;
+    esp_time.hour = hour;
+    esp_time.minute = minute;
+    esp_time.second = second;
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+                    &hour,                                                                       // NOLINT
+                    &minute, &num) == 5 &&                                                       // NOLINT
+             num == ilen) {
+    esp_time.year = year;
+    esp_time.month = month;
+    esp_time.day_of_month = day;
+    esp_time.hour = hour;
+    esp_time.minute = minute;
+    esp_time.second = 0;
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
+             num == ilen) {
+    esp_time.hour = hour;
+    esp_time.minute = minute;
+    esp_time.second = second;
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
+             num == ilen) {
+    esp_time.hour = hour;
+    esp_time.minute = minute;
+    esp_time.second = 0;
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
+             num == ilen) {
+    esp_time.year = year;
+    esp_time.month = month;
+    esp_time.day_of_month = day;
+  } else {
     return false;
-
-  const char *p = time_to_parse;
-  const char *end = time_to_parse + len;
-  uint16_t v1, v2, v3, v4, v5, v6;
-
-  // Try date formats first (start with 4-digit year)
-  if (len >= 10 && time_to_parse[4] == '-') {
-    // YYYY-MM-DD...
-    if (!parse_digits(p, end, 4, v1))
-      return false;
-    if (!expect_char(p, end, '-'))
-      return false;
-    if (!parse_digits(p, end, 2, v2))
-      return false;
-    if (!expect_char(p, end, '-'))
-      return false;
-    if (!parse_digits(p, end, 2, v3))
-      return false;
-
-    esp_time.year = v1;
-    esp_time.month = v2;
-    esp_time.day_of_month = v3;
-
-    if (p == end) {
-      // YYYY-MM-DD (date only)
-      return true;
-    }
-
-    if (!expect_char(p, end, ' '))
-      return false;
-
-    // Continue with time part: HH:MM[:SS]
-    if (!parse_digits(p, end, 2, v4))
-      return false;
-    if (!expect_char(p, end, ':'))
-      return false;
-    if (!parse_digits(p, end, 2, v5))
-      return false;
-
-    esp_time.hour = v4;
-    esp_time.minute = v5;
-
-    if (p == end) {
-      // YYYY-MM-DD HH:MM
-      esp_time.second = 0;
-      return true;
-    }
-
-    if (!expect_char(p, end, ':'))
-      return false;
-    if (!parse_digits(p, end, 2, v6))
-      return false;
-
-    esp_time.second = v6;
-    return p == end;  // YYYY-MM-DD HH:MM:SS
   }
-
-  // Try time-only formats (HH:MM[:SS])
-  if (len >= 5 && time_to_parse[2] == ':') {
-    if (!parse_digits(p, end, 2, v1))
-      return false;
-    if (!expect_char(p, end, ':'))
-      return false;
-    if (!parse_digits(p, end, 2, v2))
-      return false;
-
-    esp_time.hour = v1;
-    esp_time.minute = v2;
-
-    if (p == end) {
-      // HH:MM
-      esp_time.second = 0;
-      return true;
-    }
-
-    if (!expect_char(p, end, ':'))
-      return false;
-    if (!parse_digits(p, end, 2, v3))
-      return false;
-
-    esp_time.second = v3;
-    return p == end;  // HH:MM:SS
-  }
-
-  return false;
+  return true;
 }
 
 void ESPTime::increment_second() {
@@ -257,67 +193,27 @@ void ESPTime::recalc_timestamp_utc(bool use_day_of_year) {
 }
 
 void ESPTime::recalc_timestamp_local() {
-#ifdef USE_TIME_TIMEZONE
-  // Calculate timestamp as if fields were UTC
-  this->recalc_timestamp_utc(false);
-  if (this->timestamp == -1) {
-    return;  // Invalid time
-  }
+  struct tm tm;
 
-  // Now convert from local to UTC by adding the offset
-  // POSIX: local = utc - offset, so utc = local + offset
-  const auto &tz = time::get_global_tz();
+  tm.tm_year = this->year - 1900;
+  tm.tm_mon = this->month - 1;
+  tm.tm_mday = this->day_of_month;
+  tm.tm_hour = this->hour;
+  tm.tm_min = this->minute;
+  tm.tm_sec = this->second;
+  tm.tm_isdst = -1;
 
-  if (!tz.has_dst()) {
-    // No DST - just apply standard offset
-    this->timestamp += tz.std_offset_seconds;
-    return;
-  }
-
-  // Try both interpretations to match libc mktime() with tm_isdst=-1
-  // For ambiguous times (fall-back repeated hour), prefer standard time
-  // For invalid times (spring-forward skipped hour), libc normalizes forward
-  time_t utc_if_dst = this->timestamp + tz.dst_offset_seconds;
-  time_t utc_if_std = this->timestamp + tz.std_offset_seconds;
-
-  bool dst_valid = time::is_in_dst(utc_if_dst, tz);
-  bool std_valid = !time::is_in_dst(utc_if_std, tz);
-
-  if (dst_valid && std_valid) {
-    // Ambiguous time (repeated hour during fall-back) - prefer standard time
-    this->timestamp = utc_if_std;
-  } else if (dst_valid) {
-    // Only DST interpretation is valid
-    this->timestamp = utc_if_dst;
-  } else if (std_valid) {
-    // Only standard interpretation is valid
-    this->timestamp = utc_if_std;
-  } else {
-    // Invalid time (skipped hour during spring-forward)
-    // libc normalizes forward: 02:30 CST -> 08:30 UTC -> 03:30 CDT
-    // Using std offset achieves this since the UTC result falls during DST
-    this->timestamp = utc_if_std;
-  }
-#else
-  // No timezone support - treat as UTC
-  this->recalc_timestamp_utc(false);
-#endif
+  this->timestamp = mktime(&tm);
 }
 
 int32_t ESPTime::timezone_offset() {
-#ifdef USE_TIME_TIMEZONE
   time_t now = ::time(nullptr);
-  const auto &tz = time::get_global_tz();
-  // POSIX offset is positive west, but we return offset to add to UTC to get local
-  // So we negate the POSIX offset
-  if (time::is_in_dst(now, tz)) {
-    return -tz.dst_offset_seconds;
-  }
-  return -tz.std_offset_seconds;
-#else
-  // No timezone support - no offset
-  return 0;
-#endif
+  struct tm local_tm = *::localtime(&now);
+  local_tm.tm_isdst = 0;  // Cause mktime to ignore daylight saving time because we want to include it in the offset.
+  time_t local_time = mktime(&local_tm);
+  struct tm utc_tm = *::gmtime(&now);
+  time_t utc_time = mktime(&utc_tm);
+  return static_cast<int32_t>(local_time - utc_time);
 }
 
 bool ESPTime::operator<(const ESPTime &other) const { return this->timestamp < other.timestamp; }

esphome/core/time.h

@@ -7,10 +7,6 @@
 #include <span>
 #include <string>
 
-#ifdef USE_TIME_TIMEZONE
-#include "esphome/components/time/posix_tz.h"
-#endif
-
 namespace esphome {
 
 template<typename T> bool increment_time_value(T &current, uint16_t begin, uint16_t end);
@@ -109,17 +105,11 @@ struct ESPTime {
    * @return The generated ESPTime
    */
   static ESPTime from_epoch_local(time_t epoch) {
-#ifdef USE_TIME_TIMEZONE
-    struct tm local_tm;
-    if (time::epoch_to_local_tm(epoch, time::get_global_tz(), &local_tm)) {
-      return ESPTime::from_c_tm(&local_tm, epoch);
+    struct tm *c_tm = ::localtime(&epoch);
+    if (c_tm == nullptr) {
+      return ESPTime{};  // Return an invalid ESPTime
     }
-    // Fallback to UTC if conversion failed
-    return ESPTime::from_epoch_utc(epoch);
-#else
-    // No timezone support - return UTC (no TZ configured, localtime would return UTC anyway)
-    return ESPTime::from_epoch_utc(epoch);
-#endif
+    return ESPTime::from_c_tm(c_tm, epoch);
   }
   /** Convert an UTC epoch timestamp to a UTC time ESPTime instance.
    *

esphome/cpp_generator.py

@@ -247,23 +247,6 @@ class LogStringLiteral(Literal):
         return f"LOG_STR({cpp_string_escape(self.string)})"
 
 
-class FlashStringLiteral(Literal):
-    """A string literal wrapped in ESPHOME_F() for PROGMEM storage on ESP8266.
-
-    On ESP8266, ESPHOME_F(s) expands to F(s) which stores the string in flash (PROGMEM).
-    On other platforms, ESPHOME_F(s) expands to plain s (no-op).
-    """
-
-    __slots__ = ("string",)
-
-    def __init__(self, string: str) -> None:
-        super().__init__()
-        self.string = string
-
-    def __str__(self) -> str:
-        return f"ESPHOME_F({cpp_string_escape(self.string)})"
-
-
 class IntLiteral(Literal):
     __slots__ = ("i",)
 
@@ -778,10 +761,6 @@ async def templatable(
     if is_template(value):
         return await process_lambda(value, args, return_type=output_type)
     if to_exp is None:
-        # Automatically wrap static strings in ESPHOME_F() for PROGMEM storage on ESP8266.
-        # On other platforms ESPHOME_F() is a no-op returning const char*.
-        if isinstance(value, str) and str(output_type) == "std::string":
-            return FlashStringLiteral(value)
         return value
     if isinstance(to_exp, dict):
         return to_exp[value]

esphome/platformio_api.py

@@ -173,16 +173,7 @@ def run_compile(config, verbose):
     args = []
     if CONF_COMPILE_PROCESS_LIMIT in config[CONF_ESPHOME]:
         args += [f"-j{config[CONF_ESPHOME][CONF_COMPILE_PROCESS_LIMIT]}"]
-    result = run_platformio_cli_run(config, verbose, *args)
-
-    # Run memory analysis if enabled
-    if config.get(CONF_ESPHOME, {}).get("analyze_memory", False):
-        try:
-            analyze_memory_usage(config)
-        except Exception as e:
-            _LOGGER.warning("Failed to analyze memory usage: %s", e)
-
-    return result
+    return run_platformio_cli_run(config, verbose, *args)
 
 
 def _run_idedata(config):
@@ -436,74 +427,3 @@ class IDEData:
     def defines(self) -> list[str]:
         """Return the list of preprocessor defines from idedata."""
         return self.raw.get("defines", [])
-
-
-def analyze_memory_usage(config: dict[str, Any]) -> None:
-    """Analyze memory usage by component after compilation."""
-    # Lazy import to avoid overhead when not needed
-    from esphome.analyze_memory.cli import MemoryAnalyzerCLI
-    from esphome.analyze_memory.helpers import get_esphome_components
-
-    idedata = get_idedata(config)
-
-    # Get paths to tools
-    elf_path = idedata.firmware_elf_path
-    objdump_path = idedata.objdump_path
-    readelf_path = idedata.readelf_path
-
-    # Debug logging
-    _LOGGER.debug("ELF path from idedata: %s", elf_path)
-
-    # Check if file exists
-    if not Path(elf_path).exists():
-        # Try alternate path
-        alt_path = Path(CORE.relative_build_path(".pioenvs", CORE.name, "firmware.elf"))
-        if alt_path.exists():
-            elf_path = str(alt_path)
-            _LOGGER.debug("Using alternate ELF path: %s", elf_path)
-        else:
-            _LOGGER.warning("ELF file not found at %s or %s", elf_path, alt_path)
-            return
-
-    # Extract external components from config
-    external_components = set()
-
-    # Get the list of built-in ESPHome components
-    builtin_components = get_esphome_components()
-
-    # Special non-component keys that appear in configs
-    NON_COMPONENT_KEYS = {
-        CONF_ESPHOME,
-        "substitutions",
-        "packages",
-        "globals",
-        "<<",
-    }
-
-    # Check all top-level keys in config
-    for key in config:
-        if key not in builtin_components and key not in NON_COMPONENT_KEYS:
-            # This is an external component
-            external_components.add(key)
-
-    _LOGGER.debug("Detected external components: %s", external_components)
-
-    # Create analyzer and run analysis
-    analyzer = MemoryAnalyzerCLI(
-        elf_path, objdump_path, readelf_path, external_components
-    )
-    analyzer.analyze()
-
-    # Generate and print report
-    report = analyzer.generate_report()
-    _LOGGER.info("\n%s", report)
-
-    # Optionally save to file
-    if config.get(CONF_ESPHOME, {}).get("memory_report_file"):
-        report_file = Path(config[CONF_ESPHOME]["memory_report_file"])
-        if report_file.suffix == ".json":
-            report_file.write_text(analyzer.to_json())
-            _LOGGER.info("Memory report saved to %s", report_file)
-        else:
-            report_file.write_text(report)
-            _LOGGER.info("Memory report saved to %s", report_file)

script/cpp_unit_test.py

@@ -66,7 +66,6 @@ def create_test_config(config_name: str, includes: list[str]) -> dict:
                 ],
                 "build_flags": [
                     "-Og",  # optimize for debug
-                    "-DUSE_TIME_TIMEZONE",  # enable timezone code paths for testing
                 ],
                 "debug_build_flags": [  # only for debug builds
                     "-g3",  # max debug info

tests/components/json/common.yaml

@@ -4,16 +4,15 @@ interval:
   - interval: 60s
     then:
       - lambda: |-
-          // Test build_json - returns SerializationBuffer, use auto to avoid heap allocation
-          auto json_buf = esphome::json::build_json([](JsonObject root) {
+          // Test build_json
+          std::string json_str = esphome::json::build_json([](JsonObject root) {
             root["sensor"] = "temperature";
             root["value"] = 23.5;
             root["unit"] = "°C";
           });
-          ESP_LOGD("test", "Built JSON: %s", json_buf.c_str());
+          ESP_LOGD("test", "Built JSON: %s", json_str.c_str());
 
-          // Test parse_json - implicit conversion to std::string for backward compatibility
-          std::string json_str = json_buf;
+          // Test parse_json
           bool parse_ok = esphome::json::parse_json(json_str, [](JsonObject root) {
             if (root["sensor"].is<const char*>() && root["value"].is<float>()) {
               const char* sensor = root["sensor"];
@@ -27,10 +26,10 @@ interval:
           });
           ESP_LOGD("test", "Parse result (JSON syntax only): %s", parse_ok ? "success" : "failed");
 
-          // Test JsonBuilder class - returns SerializationBuffer
+          // Test JsonBuilder class
           esphome::json::JsonBuilder builder;
           JsonObject obj = builder.root();
           obj["test"] = "direct_builder";
           obj["count"] = 42;
-          auto result = builder.serialize();
+          std::string result = builder.serialize();
           ESP_LOGD("test", "JsonBuilder result: %s", result.c_str());

tests/integration/fixtures/api_user_services_union.yaml

@@ -1,59 +0,0 @@
-esphome:
-  name: test-user-services-union
-  friendly_name: Test User Services Union Storage
-
-esp32:
-  board: esp32dev
-  framework:
-    type: esp-idf
-
-logger:
-  level: DEBUG
-
-wifi:
-  ssid: "test"
-  password: "password"
-
-api:
-  actions:
-    # Test service with no arguments
-    - action: test_no_args
-      then:
-        - logger.log: "No args service called"
-
-    # Test service with one argument
-    - action: test_one_arg
-      variables:
-        value: int
-      then:
-        - logger.log:
-            format: "One arg service: %d"
-            args: [value]
-
-    # Test service with multiple arguments of different types
-    - action: test_multi_args
-      variables:
-        int_val: int
-        float_val: float
-        str_val: string
-        bool_val: bool
-      then:
-        - logger.log:
-            format: "Multi args: %d, %.2f, %s, %d"
-            args: [int_val, float_val, str_val.c_str(), bool_val]
-
-    # Test service with max typical arguments
-    - action: test_many_args
-      variables:
-        arg1: int
-        arg2: int
-        arg3: int
-        arg4: string
-        arg5: float
-      then:
-        - logger.log: "Many args service called"
-
-binary_sensor:
-  - platform: template
-    name: "Test Binary Sensor"
-    id: test_sensor

tests/unit_tests/test_cpp_generator.py

@@ -248,12 +248,6 @@ class TestLiterals:
             (cg.FloatLiteral(4.2), "4.2f"),
             (cg.FloatLiteral(1.23456789), "1.23456789f"),
             (cg.FloatLiteral(math.nan), "NAN"),
-            (cg.FlashStringLiteral("hello"), 'ESPHOME_F("hello")'),
-            (cg.FlashStringLiteral(""), 'ESPHOME_F("")'),
-            (
-                cg.FlashStringLiteral('quote"here'),
-                'ESPHOME_F("quote\\042here")',
-            ),
         ),
     )
     def test_str__simple(self, target: cg.Literal, expected: str):
@@ -630,75 +624,3 @@ class TestProcessLambda:
         # Test invalid tuple format (single element)
         with pytest.raises(AssertionError):
             await cg.process_lambda(lambda_obj, [(int,)])
-
-
-@pytest.mark.asyncio
-async def test_templatable__string_with_std_string_returns_flash_literal() -> None:
-    """Static string with std::string output_type returns FlashStringLiteral."""
-    result = await cg.templatable("hello", [], ct.std_string)
-
-    assert isinstance(result, cg.FlashStringLiteral)
-    assert str(result) == 'ESPHOME_F("hello")'
-
-
-@pytest.mark.asyncio
-async def test_templatable__empty_string_with_std_string() -> None:
-    """Empty static string with std::string output_type returns FlashStringLiteral."""
-    result = await cg.templatable("", [], ct.std_string)
-
-    assert isinstance(result, cg.FlashStringLiteral)
-    assert str(result) == 'ESPHOME_F("")'
-
-
-@pytest.mark.asyncio
-async def test_templatable__string_with_none_output_type() -> None:
-    """Static string with output_type=None returns raw string (no wrapping)."""
-    result = await cg.templatable("hello", [], None)
-
-    assert isinstance(result, str)
-    assert result == "hello"
-
-
-@pytest.mark.asyncio
-async def test_templatable__int_with_std_string() -> None:
-    """Non-string value with std::string output_type returns raw value."""
-    result = await cg.templatable(42, [], ct.std_string)
-
-    assert result == 42
-
-
-@pytest.mark.asyncio
-async def test_templatable__string_with_non_string_output_type() -> None:
-    """Static string with non-std::string output_type returns raw string."""
-    result = await cg.templatable("hello", [], ct.bool_)
-
-    assert isinstance(result, str)
-    assert result == "hello"
-
-
-@pytest.mark.asyncio
-async def test_templatable__with_to_exp_callable() -> None:
-    """When to_exp is provided, it is applied to non-template values."""
-    result = await cg.templatable(42, [], None, to_exp=lambda x: x * 2)
-
-    assert result == 84
-
-
-@pytest.mark.asyncio
-async def test_templatable__with_to_exp_dict() -> None:
-    """When to_exp is a dict, value is looked up."""
-    mapping: dict[str, int] = {"on": 1, "off": 0}
-    result = await cg.templatable("on", [], None, to_exp=mapping)
-
-    assert result == 1
-
-
-@pytest.mark.asyncio
-async def test_templatable__lambda_with_std_string() -> None:
-    """Lambda value returns LambdaExpression, not FlashStringLiteral."""
-    from esphome.core import Lambda
-
-    lambda_obj = Lambda('return "hello";')
-    result = await cg.templatable(lambda_obj, [], ct.std_string)
-
-    assert isinstance(result, cg.LambdaExpression)

tests/unit_tests/test_writer.py

@@ -453,7 +453,6 @@ def test_clean_build(
     mock_core.relative_pioenvs_path.return_value = pioenvs_dir
     mock_core.relative_piolibdeps_path.return_value = piolibdeps_dir
     mock_core.relative_build_path.return_value = dependencies_lock
-    mock_core.platformio_cache_dir = str(platformio_cache_dir)
 
     # Verify all exist before
     assert pioenvs_dir.exists()