[core] Avoid heap allocation in str_equals_case_insensitive with string literals (#13312)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: J. Nick Koston <nick@koston.org>

.clang-tidy.hash

@@ -1 +1 @@
-d272a88e8ca28ae9340a9a03295a566432a52cb696501908f57764475bf7ca65
+d15ae81646ac0ee76b2586716fe697f187281523ee6db566aed26542a9f98d1a

esphome/__main__.py

@@ -43,6 +43,7 @@ from esphome.const import (
     CONF_SUBSTITUTIONS,
     CONF_TOPIC,
     ENV_NOGITIGNORE,
+    KEY_NATIVE_IDF,
     PLATFORM_ESP32,
     PLATFORM_ESP8266,
     PLATFORM_RP2040,
@@ -116,6 +117,7 @@ class ArgsProtocol(Protocol):
     configuration: str
     name: str
     upload_speed: str | None
+    native_idf: bool
 
 
 def choose_prompt(options, purpose: str = None):
@@ -500,12 +502,15 @@ def wrap_to_code(name, comp):
     return wrapped
 
 
-def write_cpp(config: ConfigType) -> int:
+def write_cpp(config: ConfigType, native_idf: bool = False) -> int:
     if not get_bool_env(ENV_NOGITIGNORE):
         writer.write_gitignore()
 
+    # Store native_idf flag so esp32 component can check it
+    CORE.data[KEY_NATIVE_IDF] = native_idf
+
     generate_cpp_contents(config)
-    return write_cpp_file()
+    return write_cpp_file(native_idf=native_idf)
 
 
 def generate_cpp_contents(config: ConfigType) -> None:
@@ -519,32 +524,54 @@ def generate_cpp_contents(config: ConfigType) -> None:
     CORE.flush_tasks()
 
 
-def write_cpp_file() -> int:
+def write_cpp_file(native_idf: bool = False) -> int:
     code_s = indent(CORE.cpp_main_section)
     writer.write_cpp(code_s)
 
-    from esphome.build_gen import platformio
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome.build_gen import espidf
 
-    platformio.write_project()
+        espidf.write_project()
+    else:
+        from esphome.build_gen import platformio
+
+        platformio.write_project()
 
     return 0
 
 
 def compile_program(args: ArgsProtocol, config: ConfigType) -> int:
-    from esphome import platformio_api
+    native_idf = getattr(args, "native_idf", False)
 
     # NOTE: "Build path:" format is parsed by script/ci_memory_impact_extract.py
     # If you change this format, update the regex in that script as well
     _LOGGER.info("Compiling app... Build path: %s", CORE.build_path)
-    rc = platformio_api.run_compile(config, CORE.verbose)
-    if rc != 0:
-        return rc
+
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome import espidf_api
+
+        rc = espidf_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        # Create factory.bin and ota.bin
+        espidf_api.create_factory_bin()
+        espidf_api.create_ota_bin()
+    else:
+        from esphome import platformio_api
+
+        rc = platformio_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        idedata = platformio_api.get_idedata(config)
+        if idedata is None:
+            return 1
 
     # Check if firmware was rebuilt and emit build_info + create manifest
     _check_and_emit_build_info()
 
-    idedata = platformio_api.get_idedata(config)
-    return 0 if idedata is not None else 1
+    return 0
 
 
 def _check_and_emit_build_info() -> None:
@@ -801,7 +828,8 @@ def command_vscode(args: ArgsProtocol) -> int | None:
 
 
 def command_compile(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     if args.only_generate:
@@ -856,7 +884,8 @@ def command_logs(args: ArgsProtocol, config: ConfigType) -> int | None:
 
 
 def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     exit_code = compile_program(args, config)
@@ -1310,6 +1339,11 @@ def parse_args(argv):
         help="Only generate source code, do not compile.",
         action="store_true",
     )
+    parser_compile.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_upload = subparsers.add_parser(
         "upload",
@@ -1391,6 +1425,11 @@ def parse_args(argv):
         help="Reset the device before starting serial logs.",
         default=os.getenv("ESPHOME_SERIAL_LOGGING_RESET"),
     )
+    parser_run.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_clean = subparsers.add_parser(
         "clean-mqtt",

esphome/build_gen/espidf.py

@@ -0,0 +1,139 @@
+"""ESP-IDF direct build generator for ESPHome."""
+
+import json
+from pathlib import Path
+
+from esphome.components.esp32 import get_esp32_variant
+from esphome.core import CORE
+from esphome.helpers import mkdir_p, write_file_if_changed
+
+
+def get_available_components() -> list[str] | None:
+    """Get list of available ESP-IDF components from project_description.json.
+
+    Returns only internal ESP-IDF components, excluding external/managed
+    components (from idf_component.yml).
+    """
+    project_desc = Path(CORE.build_path) / "build" / "project_description.json"
+    if not project_desc.exists():
+        return None
+
+    try:
+        with open(project_desc, encoding="utf-8") as f:
+            data = json.load(f)
+
+        component_info = data.get("build_component_info", {})
+
+        result = []
+        for name, info in component_info.items():
+            # Exclude our own src component
+            if name == "src":
+                continue
+
+            # Exclude managed/external components
+            comp_dir = info.get("dir", "")
+            if "managed_components" in comp_dir:
+                continue
+
+            result.append(name)
+
+        return result
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def has_discovered_components() -> bool:
+    """Check if we have discovered components from a previous configure."""
+    return get_available_components() is not None
+
+
+def get_project_cmakelists() -> str:
+    """Generate the top-level CMakeLists.txt for ESP-IDF project."""
+    # Get IDF target from ESP32 variant (e.g., ESP32S3 -> esp32s3)
+    variant = get_esp32_variant()
+    idf_target = variant.lower().replace("-", "")
+
+    return f"""\
+# Auto-generated by ESPHome
+cmake_minimum_required(VERSION 3.16)
+
+set(IDF_TARGET {idf_target})
+set(EXTRA_COMPONENT_DIRS ${{CMAKE_SOURCE_DIR}}/src)
+
+include($ENV{{IDF_PATH}}/tools/cmake/project.cmake)
+project({CORE.name})
+"""
+
+
+def get_component_cmakelists(minimal: bool = False) -> str:
+    """Generate the main component CMakeLists.txt."""
+    idf_requires = [] if minimal else (get_available_components() or [])
+    requires_str = " ".join(idf_requires)
+
+    # Extract compile definitions from build flags (-DXXX -> XXX)
+    compile_defs = [flag[2:] for flag in CORE.build_flags if flag.startswith("-D")]
+    compile_defs_str = "\n    ".join(compile_defs) if compile_defs else ""
+
+    # Extract compile options (-W flags, excluding linker flags)
+    compile_opts = [
+        flag
+        for flag in CORE.build_flags
+        if flag.startswith("-W") and not flag.startswith("-Wl,")
+    ]
+    compile_opts_str = "\n    ".join(compile_opts) if compile_opts else ""
+
+    # Extract linker options (-Wl, flags)
+    link_opts = [flag for flag in CORE.build_flags if flag.startswith("-Wl,")]
+    link_opts_str = "\n    ".join(link_opts) if link_opts else ""
+
+    return f"""\
+# Auto-generated by ESPHome
+file(GLOB_RECURSE app_sources
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.c"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.c"
+)
+
+idf_component_register(
+    SRCS ${{app_sources}}
+    INCLUDE_DIRS "." "esphome"
+    REQUIRES {requires_str}
+)
+
+# Apply C++ standard
+target_compile_features(${{COMPONENT_LIB}} PUBLIC cxx_std_20)
+
+# ESPHome compile definitions
+target_compile_definitions(${{COMPONENT_LIB}} PUBLIC
+    {compile_defs_str}
+)
+
+# ESPHome compile options
+target_compile_options(${{COMPONENT_LIB}} PUBLIC
+    {compile_opts_str}
+)
+
+# ESPHome linker options
+target_link_options(${{COMPONENT_LIB}} PUBLIC
+    {link_opts_str}
+)
+"""
+
+
+def write_project(minimal: bool = False) -> None:
+    """Write ESP-IDF project files."""
+    mkdir_p(CORE.build_path)
+    mkdir_p(CORE.relative_src_path())
+
+    # Write top-level CMakeLists.txt
+    write_file_if_changed(
+        CORE.relative_build_path("CMakeLists.txt"),
+        get_project_cmakelists(),
+    )
+
+    # Write component CMakeLists.txt in src/
+    write_file_if_changed(
+        CORE.relative_src_path("CMakeLists.txt"),
+        get_component_cmakelists(minimal=minimal),
+    )

esphome/components/api/api_frame_helper_noise.cpp

@@ -3,6 +3,7 @@
 #ifdef USE_API_NOISE
 #include "api_connection.h"  // For ClientInfo struct
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
@@ -256,28 +257,30 @@ APIError APINoiseFrameHelper::state_action_() {
   }
   if (state_ == State::SERVER_HELLO) {
     // send server hello
-    constexpr size_t mac_len = 13;  // 12 hex chars + null terminator
     const std::string &name = App.get_name();
-    char mac[mac_len];
+    char mac[MAC_ADDRESS_BUFFER_SIZE];
     get_mac_address_into_buffer(mac);
 
     // Calculate positions and sizes
     size_t name_len = name.size() + 1;  // including null terminator
     size_t name_offset = 1;
     size_t mac_offset = name_offset + name_len;
-    size_t total_size = 1 + name_len + mac_len;
+    size_t total_size = 1 + name_len + MAC_ADDRESS_BUFFER_SIZE;
 
-    auto msg = std::make_unique<uint8_t[]>(total_size);
+    // 1 (proto) + name (max ESPHOME_DEVICE_NAME_MAX_LEN) + 1 (name null)
+    // + mac (MAC_ADDRESS_BUFFER_SIZE - 1) + 1 (mac null)
+    constexpr size_t max_msg_size = 1 + ESPHOME_DEVICE_NAME_MAX_LEN + 1 + MAC_ADDRESS_BUFFER_SIZE;
+    uint8_t msg[max_msg_size];
 
     // chosen proto
     msg[0] = 0x01;
 
     // node name, terminated by null byte
-    std::memcpy(msg.get() + name_offset, name.c_str(), name_len);
+    std::memcpy(msg + name_offset, name.c_str(), name_len);
     // node mac, terminated by null byte
-    std::memcpy(msg.get() + mac_offset, mac, mac_len);
+    std::memcpy(msg + mac_offset, mac, MAC_ADDRESS_BUFFER_SIZE);
 
-    aerr = write_frame_(msg.get(), total_size);
+    aerr = write_frame_(msg, total_size);
     if (aerr != APIError::OK)
       return aerr;
 
@@ -353,35 +356,32 @@ APIError APINoiseFrameHelper::state_action_() {
   return APIError::OK;
 }
 void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reason) {
+  // Max reject message: "Bad handshake packet len" (24) + 1 (failure byte) = 25 bytes
+  uint8_t data[32];
+  data[0] = 0x01;  // failure
+
 #ifdef USE_STORE_LOG_STR_IN_FLASH
   // On ESP8266 with flash strings, we need to use PROGMEM-aware functions
   size_t reason_len = strlen_P(reinterpret_cast<PGM_P>(reason));
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message from PROGMEM
   if (reason_len > 0) {
-    memcpy_P(data.get() + 1, reinterpret_cast<PGM_P>(reason), reason_len);
+    memcpy_P(data + 1, reinterpret_cast<PGM_P>(reason), reason_len);
   }
 #else
   // Normal memory access
   const char *reason_str = LOG_STR_ARG(reason);
   size_t reason_len = strlen(reason_str);
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message in bulk
   if (reason_len > 0) {
-    std::memcpy(data.get() + 1, reason_str, reason_len);
+    // NOLINTNEXTLINE(bugprone-not-null-terminated-result) - binary protocol, not a C string
+    std::memcpy(data + 1, reason_str, reason_len);
   }
 #endif
 
+  size_t data_size = reason_len + 1;
+
   // temporarily remove failed state
   auto orig_state = state_;
   state_ = State::EXPLICIT_REJECT;
-  write_frame_(data.get(), data_size);
+  write_frame_(data, data_size);
   state_ = orig_state;
 }
 APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {

esphome/components/bluetooth_proxy/bluetooth_connection.cpp

@@ -135,8 +135,8 @@ void BluetoothConnection::loop() {
   // - For V3_WITH_CACHE: Services are never sent, disable after INIT state
   // - For V3_WITHOUT_CACHE: Disable only after service discovery is complete
   //   (send_service_ == DONE_SENDING_SERVICES, which is only set after services are sent)
-  if (this->state_ != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
-                                                   this->send_service_ == DONE_SENDING_SERVICES)) {
+  if (this->state() != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
+                                                    this->send_service_ == DONE_SENDING_SERVICES)) {
     this->disable_loop();
   }
 }

esphome/components/cc1101/cc1101.cpp

@@ -152,6 +152,13 @@ void CC1101Component::setup() {
   }
 }
 
+void CC1101Component::call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) {
+  for (auto &listener : this->listeners_) {
+    listener->on_packet(packet, freq_offset, rssi, lqi);
+  }
+  this->packet_trigger_->trigger(packet, freq_offset, rssi, lqi);
+}
+
 void CC1101Component::loop() {
   if (this->state_.PKT_FORMAT != static_cast<uint8_t>(PacketFormat::PACKET_FORMAT_FIFO) || this->gdo0_pin_ == nullptr ||
       !this->gdo0_pin_->digital_read()) {
@@ -198,7 +205,7 @@ void CC1101Component::loop() {
   bool crc_ok = (this->state_.LQI & STATUS_CRC_OK_MASK) != 0;
   uint8_t lqi = this->state_.LQI & STATUS_LQI_MASK;
   if (this->state_.CRC_EN == 0 || crc_ok) {
-    this->packet_trigger_->trigger(this->packet_, freq_offset, rssi, lqi);
+    this->call_listeners_(this->packet_, freq_offset, rssi, lqi);
   }
 
   // Return to rx

esphome/components/cc1101/cc1101.h

@@ -11,6 +11,11 @@ namespace esphome::cc1101 {
 
 enum class CC1101Error { NONE = 0, TIMEOUT, PARAMS, CRC_ERROR, FIFO_OVERFLOW, PLL_LOCK };
 
+class CC1101Listener {
+ public:
+  virtual void on_packet(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) = 0;
+};
+
 class CC1101Component : public Component,
                         public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_LOW,
                                               spi::CLOCK_PHASE_LEADING, spi::DATA_RATE_1MHZ> {
@@ -73,6 +78,7 @@ class CC1101Component : public Component,
 
   // Packet mode operations
   CC1101Error transmit_packet(const std::vector<uint8_t> &packet);
+  void register_listener(CC1101Listener *listener) { this->listeners_.push_back(listener); }
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *get_packet_trigger() const { return this->packet_trigger_; }
 
  protected:
@@ -89,9 +95,11 @@ class CC1101Component : public Component,
   InternalGPIOPin *gdo0_pin_{nullptr};
 
   // Packet handling
+  void call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi);
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *packet_trigger_{
       new Trigger<std::vector<uint8_t>, float, float, uint8_t>()};
   std::vector<uint8_t> packet_;
+  std::vector<CC1101Listener *> listeners_;
 
   // Low-level Helpers
   uint8_t strobe_(Command cmd);

esphome/components/datetime/date_entity.cpp

@@ -106,9 +106,9 @@ DateCall &DateCall::set_date(uint16_t year, uint8_t month, uint8_t day) {
 
 DateCall &DateCall::set_date(ESPTime time) { return this->set_date(time.year, time.month, time.day_of_month); };
 
-DateCall &DateCall::set_date(const std::string &date) {
+DateCall &DateCall::set_date(const char *date, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(date, val)) {
+  if (!ESPTime::strptime(date, len, val)) {
     ESP_LOGE(TAG, "Could not convert the date string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/date_entity.h

@@ -67,7 +67,9 @@ class DateCall {
   void perform();
   DateCall &set_date(uint16_t year, uint8_t month, uint8_t day);
   DateCall &set_date(ESPTime time);
-  DateCall &set_date(const std::string &date);
+  DateCall &set_date(const char *date, size_t len);
+  DateCall &set_date(const char *date) { return this->set_date(date, strlen(date)); }
+  DateCall &set_date(const std::string &date) { return this->set_date(date.c_str(), date.size()); }
 
   DateCall &set_year(uint16_t year) {
     this->year_ = year;

esphome/components/datetime/datetime_entity.cpp

@@ -163,9 +163,9 @@ DateTimeCall &DateTimeCall::set_datetime(ESPTime datetime) {
                             datetime.second);
 };
 
-DateTimeCall &DateTimeCall::set_datetime(const std::string &datetime) {
+DateTimeCall &DateTimeCall::set_datetime(const char *datetime, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(datetime, val)) {
+  if (!ESPTime::strptime(datetime, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/datetime_entity.h

@@ -71,7 +71,11 @@ class DateTimeCall {
   void perform();
   DateTimeCall &set_datetime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second);
   DateTimeCall &set_datetime(ESPTime datetime);
-  DateTimeCall &set_datetime(const std::string &datetime);
+  DateTimeCall &set_datetime(const char *datetime, size_t len);
+  DateTimeCall &set_datetime(const char *datetime) { return this->set_datetime(datetime, strlen(datetime)); }
+  DateTimeCall &set_datetime(const std::string &datetime) {
+    return this->set_datetime(datetime.c_str(), datetime.size());
+  }
   DateTimeCall &set_datetime(time_t epoch_seconds);
 
   DateTimeCall &set_year(uint16_t year) {

esphome/components/datetime/time_entity.cpp

@@ -74,9 +74,9 @@ TimeCall &TimeCall::set_time(uint8_t hour, uint8_t minute, uint8_t second) {
 
 TimeCall &TimeCall::set_time(ESPTime time) { return this->set_time(time.hour, time.minute, time.second); };
 
-TimeCall &TimeCall::set_time(const std::string &time) {
+TimeCall &TimeCall::set_time(const char *time, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(time, val)) {
+  if (!ESPTime::strptime(time, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/time_entity.h

@@ -69,7 +69,9 @@ class TimeCall {
   void perform();
   TimeCall &set_time(uint8_t hour, uint8_t minute, uint8_t second);
   TimeCall &set_time(ESPTime time);
-  TimeCall &set_time(const std::string &time);
+  TimeCall &set_time(const char *time, size_t len);
+  TimeCall &set_time(const char *time) { return this->set_time(time, strlen(time)); }
+  TimeCall &set_time(const std::string &time) { return this->set_time(time.c_str(), time.size()); }
 
   TimeCall &set_hour(uint8_t hour) {
     this->hour_ = hour;

esphome/components/debug/debug_esp8266.cpp

@@ -3,21 +3,80 @@
 #include "esphome/core/log.h"
 #include <Esp.h>
 
+extern "C" {
+#include <user_interface.h>
+
+// Global reset info struct populated by SDK at boot
+extern struct rst_info resetInfo;
+
+// Core version - either a string pointer or a version number to format as hex
+extern uint32_t core_version;
+extern const char *core_release;
+}
+
 namespace esphome {
 namespace debug {
 
 static const char *const TAG = "debug";
 
+// Get reset reason string from reason code (no heap allocation)
+// Returns LogString* pointing to flash (PROGMEM) on ESP8266
+static const LogString *get_reset_reason_str(uint32_t reason) {
+  switch (reason) {
+    case REASON_DEFAULT_RST:
+      return LOG_STR("Power On");
+    case REASON_WDT_RST:
+      return LOG_STR("Hardware Watchdog");
+    case REASON_EXCEPTION_RST:
+      return LOG_STR("Exception");
+    case REASON_SOFT_WDT_RST:
+      return LOG_STR("Software Watchdog");
+    case REASON_SOFT_RESTART:
+      return LOG_STR("Software/System restart");
+    case REASON_DEEP_SLEEP_AWAKE:
+      return LOG_STR("Deep-Sleep Wake");
+    case REASON_EXT_SYS_RST:
+      return LOG_STR("External System");
+    default:
+      return LOG_STR("Unknown");
+  }
+}
+
+// Size for core version hex buffer
+static constexpr size_t CORE_VERSION_BUFFER_SIZE = 12;
+
+// Get core version string (no heap allocation)
+// Returns either core_release directly or formats core_version as hex into provided buffer
+static const char *get_core_version_str(std::span<char, CORE_VERSION_BUFFER_SIZE> buffer) {
+  if (core_release != nullptr) {
+    return core_release;
+  }
+  snprintf_P(buffer.data(), CORE_VERSION_BUFFER_SIZE, PSTR("%08x"), core_version);
+  return buffer.data();
+}
+
+// Size for reset info buffer
+static constexpr size_t RESET_INFO_BUFFER_SIZE = 200;
+
+// Get detailed reset info string (no heap allocation)
+// For watchdog/exception resets, includes detailed exception info
+static const char *get_reset_info_str(std::span<char, RESET_INFO_BUFFER_SIZE> buffer, uint32_t reason) {
+  if (reason >= REASON_WDT_RST && reason <= REASON_SOFT_WDT_RST) {
+    snprintf_P(buffer.data(), RESET_INFO_BUFFER_SIZE,
+               PSTR("Fatal exception:%d flag:%d (%s) epc1:0x%08x epc2:0x%08x epc3:0x%08x excvaddr:0x%08x depc:0x%08x"),
+               static_cast<int>(resetInfo.exccause), static_cast<int>(reason),
+               LOG_STR_ARG(get_reset_reason_str(reason)), resetInfo.epc1, resetInfo.epc2, resetInfo.epc3,
+               resetInfo.excvaddr, resetInfo.depc);
+    return buffer.data();
+  }
+  return LOG_STR_ARG(get_reset_reason_str(reason));
+}
+
 const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
-  char *buf = buffer.data();
-#if !defined(CLANG_TIDY)
-  String reason = ESP.getResetReason();  // NOLINT
-  snprintf_P(buf, RESET_REASON_BUFFER_SIZE, PSTR("%s"), reason.c_str());
-  return buf;
-#else
-  buf[0] = '\0';
-  return buf;
-#endif
+  // Copy from flash to provided buffer
+  strncpy_P(buffer.data(), (PGM_P) get_reset_reason_str(resetInfo.reason), RESET_REASON_BUFFER_SIZE - 1);
+  buffer[RESET_REASON_BUFFER_SIZE - 1] = '\0';
+  return buffer.data();
 }
 
 const char *DebugComponent::get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
@@ -33,37 +92,42 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   constexpr size_t size = DEVICE_INFO_BUFFER_SIZE;
   char *buf = buffer.data();
 
-  const char *flash_mode;
+  const LogString *flash_mode;
   switch (ESP.getFlashChipMode()) {  // NOLINT(readability-static-accessed-through-instance)
     case FM_QIO:
-      flash_mode = "QIO";
+      flash_mode = LOG_STR("QIO");
       break;
     case FM_QOUT:
-      flash_mode = "QOUT";
+      flash_mode = LOG_STR("QOUT");
       break;
     case FM_DIO:
-      flash_mode = "DIO";
+      flash_mode = LOG_STR("DIO");
       break;
     case FM_DOUT:
-      flash_mode = "DOUT";
+      flash_mode = LOG_STR("DOUT");
       break;
     default:
-      flash_mode = "UNKNOWN";
+      flash_mode = LOG_STR("UNKNOWN");
   }
-  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT
-  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT
-  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed, flash_mode);
+  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT(readability-static-accessed-through-instance)
+  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT(readability-static-accessed-through-instance)
+  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed,
+           LOG_STR_ARG(flash_mode));
   pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
-                          flash_mode);
+                          LOG_STR_ARG(flash_mode));
 
-#if !defined(CLANG_TIDY)
   char reason_buffer[RESET_REASON_BUFFER_SIZE];
-  const char *reset_reason = get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
+  const char *reset_reason = get_reset_reason_(reason_buffer);
+  char core_version_buffer[CORE_VERSION_BUFFER_SIZE];
+  char reset_info_buffer[RESET_INFO_BUFFER_SIZE];
+  // NOLINTBEGIN(readability-static-accessed-through-instance)
   uint32_t chip_id = ESP.getChipId();
   uint8_t boot_version = ESP.getBootVersion();
   uint8_t boot_mode = ESP.getBootMode();
   uint8_t cpu_freq = ESP.getCpuFreqMHz();
   uint32_t flash_chip_id = ESP.getFlashChipId();
+  const char *sdk_version = ESP.getSdkVersion();
+  // NOLINTEND(readability-static-accessed-through-instance)
 
   ESP_LOGD(TAG,
            "Chip ID: 0x%08" PRIX32 "\n"
@@ -74,19 +138,18 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
            "Flash Chip ID=0x%08" PRIX32 "\n"
            "Reset Reason: %s\n"
            "Reset Info: %s",
-           chip_id, ESP.getSdkVersion(), ESP.getCoreVersion().c_str(), boot_version, boot_mode, cpu_freq, flash_chip_id,
-           reset_reason, ESP.getResetInfo().c_str());
+           chip_id, sdk_version, get_core_version_str(core_version_buffer), boot_version, boot_mode, cpu_freq,
+           flash_chip_id, reset_reason, get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
   pos = buf_append_printf(buf, size, pos, "|Chip: 0x%08" PRIX32, chip_id);
-  pos = buf_append_printf(buf, size, pos, "|SDK: %s", ESP.getSdkVersion());
-  pos = buf_append_printf(buf, size, pos, "|Core: %s", ESP.getCoreVersion().c_str());
+  pos = buf_append_printf(buf, size, pos, "|SDK: %s", sdk_version);
+  pos = buf_append_printf(buf, size, pos, "|Core: %s", get_core_version_str(core_version_buffer));
   pos = buf_append_printf(buf, size, pos, "|Boot: %u", boot_version);
   pos = buf_append_printf(buf, size, pos, "|Mode: %u", boot_mode);
   pos = buf_append_printf(buf, size, pos, "|CPU: %u", cpu_freq);
   pos = buf_append_printf(buf, size, pos, "|Flash: 0x%08" PRIX32, flash_chip_id);
   pos = buf_append_printf(buf, size, pos, "|Reset: %s", reset_reason);
-  pos = buf_append_printf(buf, size, pos, "|%s", ESP.getResetInfo().c_str());
-#endif
+  pos = buf_append_printf(buf, size, pos, "|%s", get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
   return pos;
 }

esphome/components/esp32/__init__.py

@@ -34,6 +34,7 @@ from esphome.const import (
     KEY_CORE,
     KEY_FRAMEWORK_VERSION,
     KEY_NAME,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_ESP32,
@@ -53,6 +54,7 @@ from .const import (  # noqa
     KEY_COMPONENTS,
     KEY_ESP32,
     KEY_EXTRA_BUILD_FILES,
+    KEY_FLASH_SIZE,
     KEY_PATH,
     KEY_REF,
     KEY_REPO,
@@ -199,6 +201,7 @@ def set_core_data(config):
     )
 
     CORE.data[KEY_ESP32][KEY_BOARD] = config[CONF_BOARD]
+    CORE.data[KEY_ESP32][KEY_FLASH_SIZE] = config[CONF_FLASH_SIZE]
     CORE.data[KEY_ESP32][KEY_VARIANT] = variant
     CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES] = {}
 
@@ -962,12 +965,54 @@ async def _add_yaml_idf_components(components: list[ConfigType]):
 
 
 async def to_code(config):
-    cg.add_platformio_option("board", config[CONF_BOARD])
-    cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
-    cg.add_platformio_option(
-        "board_upload.maximum_size",
-        int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
-    )
+    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
+    conf = config[CONF_FRAMEWORK]
+
+    # Check if using native ESP-IDF build (--native-idf)
+    use_platformio = not CORE.data.get(KEY_NATIVE_IDF, False)
+    if use_platformio:
+        # Clear IDF environment variables to avoid conflicts with PlatformIO's ESP-IDF
+        # but keep them when using --native-idf for native ESP-IDF builds
+        for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
+            os.environ.pop(clean_var, None)
+
+        cg.add_platformio_option("lib_ldf_mode", "off")
+        cg.add_platformio_option("lib_compat_mode", "strict")
+        cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
+        cg.add_platformio_option("board", config[CONF_BOARD])
+        cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
+        cg.add_platformio_option(
+            "board_upload.maximum_size",
+            int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
+        )
+
+        if CONF_SOURCE in conf:
+            cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
+
+        add_extra_script(
+            "pre",
+            "pre_build.py",
+            Path(__file__).parent / "pre_build.py.script",
+        )
+
+        add_extra_script(
+            "post",
+            "post_build.py",
+            Path(__file__).parent / "post_build.py.script",
+        )
+
+        # In testing mode, add IRAM fix script to allow linking grouped component tests
+        # Similar to ESP8266's approach but for ESP-IDF
+        if CORE.testing_mode:
+            cg.add_build_flag("-DESPHOME_TESTING_MODE")
+            add_extra_script(
+                "pre",
+                "iram_fix.py",
+                Path(__file__).parent / "iram_fix.py.script",
+            )
+    else:
+        cg.add_build_flag("-Wno-error=format")
+
     cg.set_cpp_standard("gnu++20")
     cg.add_build_flag("-DUSE_ESP32")
     cg.add_build_flag("-Wl,-z,noexecstack")
@@ -977,79 +1022,49 @@ async def to_code(config):
     cg.add_define("ESPHOME_VARIANT", VARIANT_FRIENDLY[variant])
     cg.add_define(ThreadModel.MULTI_ATOMICS)
 
-    cg.add_platformio_option("lib_ldf_mode", "off")
-    cg.add_platformio_option("lib_compat_mode", "strict")
-
-    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
-
-    conf = config[CONF_FRAMEWORK]
-    cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
-    if CONF_SOURCE in conf:
-        cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
-
     if conf[CONF_ADVANCED][CONF_IGNORE_EFUSE_CUSTOM_MAC]:
         cg.add_define("USE_ESP32_IGNORE_EFUSE_CUSTOM_MAC")
 
-    for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
-        os.environ.pop(clean_var, None)
-
     # Set the location of the IDF component manager cache
     os.environ["IDF_COMPONENT_CACHE_PATH"] = str(
         CORE.relative_internal_path(".espressif")
     )
 
-    add_extra_script(
-        "pre",
-        "pre_build.py",
-        Path(__file__).parent / "pre_build.py.script",
-    )
-
-    add_extra_script(
-        "post",
-        "post_build.py",
-        Path(__file__).parent / "post_build.py.script",
-    )
-
-    # In testing mode, add IRAM fix script to allow linking grouped component tests
-    # Similar to ESP8266's approach but for ESP-IDF
-    if CORE.testing_mode:
-        cg.add_build_flag("-DESPHOME_TESTING_MODE")
-        add_extra_script(
-            "pre",
-            "iram_fix.py",
-            Path(__file__).parent / "iram_fix.py.script",
-        )
-
     if conf[CONF_TYPE] == FRAMEWORK_ESP_IDF:
-        cg.add_platformio_option("framework", "espidf")
         cg.add_build_flag("-DUSE_ESP_IDF")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ESP_IDF")
+        if use_platformio:
+            cg.add_platformio_option("framework", "espidf")
     else:
-        cg.add_platformio_option("framework", "arduino, espidf")
         cg.add_build_flag("-DUSE_ARDUINO")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ARDUINO")
+        if use_platformio:
+            cg.add_platformio_option("framework", "arduino, espidf")
+
+            # Add IDF framework source for Arduino builds to ensure it uses the same version as
+            # the ESP-IDF framework
+            if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
+                cg.add_platformio_option(
+                    "platform_packages",
+                    [_format_framework_espidf_version(idf_ver, None)],
+                )
+
+            # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
+            if get_esp32_variant() == VARIANT_ESP32S2:
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
+                cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
+
         cg.add_define(
             "USE_ARDUINO_VERSION_CODE",
             cg.RawExpression(
                 f"VERSION_CODE({framework_ver.major}, {framework_ver.minor}, {framework_ver.patch})"
             ),
         )
+
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_PSK_MODES", True)
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True)
 
-        # Add IDF framework source for Arduino builds to ensure it uses the same version as
-        # the ESP-IDF framework
-        if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
-            cg.add_platformio_option(
-                "platform_packages", [_format_framework_espidf_version(idf_ver, None)]
-            )
-
-        # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
-        if get_esp32_variant() == VARIANT_ESP32S2:
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
-            cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
-
     cg.add_build_flag("-Wno-nonnull-compare")
 
     add_idf_sdkconfig_option(f"CONFIG_IDF_TARGET_{variant}", True)
@@ -1196,7 +1211,8 @@ async def to_code(config):
             "CONFIG_VFS_SUPPORT_DIR", not advanced[CONF_DISABLE_VFS_SUPPORT_DIR]
         )
 
-    cg.add_platformio_option("board_build.partitions", "partitions.csv")
+    if use_platformio:
+        cg.add_platformio_option("board_build.partitions", "partitions.csv")
     if CONF_PARTITIONS in config:
         add_extra_build_file(
             "partitions.csv", CORE.relative_config_path(config[CONF_PARTITIONS])
@@ -1361,19 +1377,16 @@ def copy_files():
     _write_idf_component_yml()
 
     if "partitions.csv" not in CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES]:
+        flash_size = CORE.data[KEY_ESP32][KEY_FLASH_SIZE]
         if CORE.using_arduino:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_arduino_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_arduino_partition_csv(flash_size),
             )
         else:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_idf_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_idf_partition_csv(flash_size),
             )
     # IDF build scripts look for version string to put in the build.
     # However, if the build path does not have an initialized git repo,

esphome/components/esp32/const.py

@@ -2,6 +2,7 @@ import esphome.codegen as cg
 
 KEY_ESP32 = "esp32"
 KEY_BOARD = "board"
+KEY_FLASH_SIZE = "flash_size"
 KEY_VARIANT = "variant"
 KEY_SDKCONFIG_OPTIONS = "sdkconfig_options"
 KEY_COMPONENTS = "components"

esphome/components/esp32/preferences.cpp

@@ -181,7 +181,8 @@ class ESP32Preferences : public ESPPreferences {
     if (actual_len != to_save.len) {
       return true;
     }
-    auto stored_data = std::make_unique<uint8_t[]>(actual_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(actual_len);
     err = nvs_get_blob(nvs_handle, key_str, stored_data.get(), &actual_len);
     if (err != 0) {
       ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", key_str, esp_err_to_name(err));

esphome/components/esp32_ble_client/ble_client_base.cpp

@@ -50,7 +50,7 @@ void BLEClientBase::loop() {
     this->set_state(espbt::ClientState::INIT);
     return;
   }
-  if (this->state_ == espbt::ClientState::INIT) {
+  if (this->state() == espbt::ClientState::INIT) {
     auto ret = esp_ble_gattc_app_register(this->app_id);
     if (ret) {
       ESP_LOGE(TAG, "gattc app register failed. app_id=%d code=%d", this->app_id, ret);
@@ -60,7 +60,7 @@ void BLEClientBase::loop() {
   }
   // If idle, we can disable the loop as connect()
   // will enable it again when a connection is needed.
-  else if (this->state_ == espbt::ClientState::IDLE) {
+  else if (this->state() == espbt::ClientState::IDLE) {
     this->disable_loop();
   }
 }
@@ -86,7 +86,7 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
     return false;
   if (this->address_ == 0 || device.address_uint64() != this->address_)
     return false;
-  if (this->state_ != espbt::ClientState::IDLE)
+  if (this->state() != espbt::ClientState::IDLE)
     return false;
 
   this->log_event_("Found device");
@@ -102,10 +102,10 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
 
 void BLEClientBase::connect() {
   // Prevent duplicate connection attempts
-  if (this->state_ == espbt::ClientState::CONNECTING || this->state_ == espbt::ClientState::CONNECTED ||
-      this->state_ == espbt::ClientState::ESTABLISHED) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->state() == espbt::ClientState::CONNECTED ||
+      this->state() == espbt::ClientState::ESTABLISHED) {
     ESP_LOGW(TAG, "[%d] [%s] Connection already in progress, state=%s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
   ESP_LOGI(TAG, "[%d] [%s] 0x%02x Connecting", this->connection_index_, this->address_str_, this->remote_addr_type_);
@@ -133,12 +133,12 @@ void BLEClientBase::connect() {
 esp_err_t BLEClientBase::pair() { return esp_ble_set_encryption(this->remote_bda_, ESP_BLE_SEC_ENCRYPT); }
 
 void BLEClientBase::disconnect() {
-  if (this->state_ == espbt::ClientState::IDLE || this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::IDLE || this->state() == espbt::ClientState::DISCONNECTING) {
     ESP_LOGI(TAG, "[%d] [%s] Disconnect requested, but already %s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
-  if (this->state_ == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
     ESP_LOGD(TAG, "[%d] [%s] Disconnect before connected, disconnect scheduled", this->connection_index_,
              this->address_str_);
     this->want_disconnect_ = true;
@@ -150,7 +150,7 @@ void BLEClientBase::disconnect() {
 void BLEClientBase::unconditional_disconnect() {
   // Disconnect without checking the state.
   ESP_LOGI(TAG, "[%d] [%s] Disconnecting (conn_id: %d).", this->connection_index_, this->address_str_, this->conn_id_);
-  if (this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::DISCONNECTING) {
     this->log_error_("Already disconnecting");
     return;
   }
@@ -170,7 +170,7 @@ void BLEClientBase::unconditional_disconnect() {
     this->log_gattc_warning_("esp_ble_gattc_close", err);
   }
 
-  if (this->state_ == espbt::ClientState::DISCOVERED) {
+  if (this->state() == espbt::ClientState::DISCOVERED) {
     this->set_address(0);
     this->set_state(espbt::ClientState::IDLE);
   } else {
@@ -295,18 +295,18 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       // ESP-IDF's BLE stack may send ESP_GATTC_OPEN_EVT after esp_ble_gattc_open() returns an
       // error, if the error occurred at the BTA/GATT layer. This can result in the event
       // arriving after we've already transitioned to IDLE state.
-      if (this->state_ == espbt::ClientState::IDLE) {
+      if (this->state() == espbt::ClientState::IDLE) {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in IDLE state (status=%d), ignoring", this->connection_index_,
                  this->address_str_, param->open.status);
         break;
       }
 
-      if (this->state_ != espbt::ClientState::CONNECTING) {
+      if (this->state() != espbt::ClientState::CONNECTING) {
         // This should not happen but lets log it in case it does
         // because it means we have a bad assumption about how the
         // ESP BT stack works.
         ESP_LOGE(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in %s state (status=%d)", this->connection_index_,
-                 this->address_str_, espbt::client_state_to_string(this->state_), param->open.status);
+                 this->address_str_, espbt::client_state_to_string(this->state()), param->open.status);
       }
       if (param->open.status != ESP_GATT_OK && param->open.status != ESP_GATT_ALREADY_OPEN) {
         this->log_gattc_warning_("Connection open", param->open.status);
@@ -327,7 +327,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       if (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE) {
         // Cached connections already connected with medium parameters, no update needed
         // only set our state, subclients might have more stuff to do yet.
-        this->state_ = espbt::ClientState::ESTABLISHED;
+        this->set_state_internal_(espbt::ClientState::ESTABLISHED);
         break;
       }
       // For V3_WITHOUT_CACHE, we already set fast params before connecting
@@ -356,7 +356,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
         return false;
       // Check if we were disconnected while waiting for service discovery
       if (param->disconnect.reason == ESP_GATT_CONN_TERMINATE_PEER_USER &&
-          this->state_ == espbt::ClientState::CONNECTED) {
+          this->state() == espbt::ClientState::CONNECTED) {
         this->log_warning_("Remote closed during discovery");
       } else {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_DISCONNECT_EVT, reason 0x%02x", this->connection_index_, this->address_str_,
@@ -433,7 +433,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
 #endif
       }
       ESP_LOGI(TAG, "[%d] [%s] Service discovery complete", this->connection_index_, this->address_str_);
-      this->state_ = espbt::ClientState::ESTABLISHED;
+      this->set_state_internal_(espbt::ClientState::ESTABLISHED);
       break;
     }
     case ESP_GATTC_READ_DESCR_EVT: {

esphome/components/esp32_ble_client/ble_client_base.h

@@ -44,7 +44,7 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   void unconditional_disconnect();
   void release_services();
 
-  bool connected() { return this->state_ == espbt::ClientState::ESTABLISHED; }
+  bool connected() { return this->state() == espbt::ClientState::ESTABLISHED; }
 
   void set_auto_connect(bool auto_connect) { this->auto_connect_ = auto_connect; }
 

esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp

@@ -105,15 +105,13 @@ void ESP32BLETracker::loop() {
   }
 
   // Check for scan timeout - moved here from scheduler to avoid false reboots
-  // when the loop is blocked
+  // when the loop is blocked. This must run every iteration for safety.
   if (this->scanner_state_ == ScannerState::RUNNING) {
     switch (this->scan_timeout_state_) {
       case ScanTimeoutState::MONITORING: {
-        uint32_t now = App.get_loop_component_start_time();
-        uint32_t timeout_ms = this->scan_duration_ * 2000;
         // Robust time comparison that handles rollover correctly
         // This works because unsigned arithmetic wraps around predictably
-        if ((now - this->scan_start_time_) > timeout_ms) {
+        if ((App.get_loop_component_start_time() - this->scan_start_time_) > this->scan_timeout_ms_) {
           // First time we've seen the timeout exceeded - wait one more loop iteration
           // This ensures all components have had a chance to process pending events
           // This is because esp32_ble may not have run yet and called
@@ -128,13 +126,31 @@ void ESP32BLETracker::loop() {
         ESP_LOGE(TAG, "Scan never terminated, rebooting");
         App.reboot();
         break;
-
       case ScanTimeoutState::INACTIVE:
-        // This case should be unreachable - scanner and timeout states are always synchronized
         break;
     }
   }
 
+  // Fast path: skip expensive client state counting and processing
+  // if no state has changed since last loop iteration.
+  //
+  // How state changes ensure we reach the code below:
+  // - handle_scanner_failure_(): scanner_state_ becomes FAILED via set_scanner_state_(), or
+  //   scan_set_param_failed_ requires scanner_state_==RUNNING which can only be reached via
+  //   set_scanner_state_(RUNNING) in gap_scan_start_complete_() (scan params are set during
+  //   STARTING, not RUNNING, so version is always incremented before this condition is true)
+  // - start_scan_(): scanner_state_ becomes IDLE via set_scanner_state_() in cleanup_scan_state_()
+  // - try_promote_discovered_clients_(): client enters DISCOVERED via set_state(), or
+  //   connecting client finishes (state change), or scanner reaches RUNNING/IDLE
+  //
+  // All conditions that affect the logic below are tied to state changes that increment
+  // state_version_, so the fast path is safe.
+  if (this->state_version_ == this->last_processed_version_) {
+    return;
+  }
+  this->last_processed_version_ = this->state_version_;
+
+  // State changed - do full processing
   ClientStateCounts counts = this->count_client_states_();
   if (counts != this->client_state_counts_) {
     this->client_state_counts_ = counts;
@@ -142,6 +158,7 @@ void ESP32BLETracker::loop() {
              this->client_state_counts_.discovered, this->client_state_counts_.disconnecting);
   }
 
+  // Scanner failure: reached when set_scanner_state_(FAILED) or scan_set_param_failed_ set
   if (this->scanner_state_ == ScannerState::FAILED ||
       (this->scan_set_param_failed_ && this->scanner_state_ == ScannerState::RUNNING)) {
     this->handle_scanner_failure_();
@@ -160,6 +177,8 @@ void ESP32BLETracker::loop() {
 
   */
 
+  // Start scan: reached when scanner_state_ becomes IDLE (via set_scanner_state_()) and
+  // all clients are idle (their state changes increment version when they finish)
   if (this->scanner_state_ == ScannerState::IDLE && !counts.connecting && !counts.disconnecting && !counts.discovered) {
 #ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
     this->update_coex_preference_(false);
@@ -168,8 +187,9 @@ void ESP32BLETracker::loop() {
       this->start_scan_(false);  // first = false
     }
   }
-  // If there is a discovered client and no connecting
-  // clients, then promote the discovered client to ready to connect.
+  // Promote discovered clients: reached when a client's state becomes DISCOVERED (via set_state()),
+  // or when a blocking condition clears (connecting client finishes, scanner reaches RUNNING/IDLE).
+  // All these trigger state_version_ increment, so we'll process and check promotion eligibility.
   // We check both RUNNING and IDLE states because:
   // - RUNNING: gap_scan_event_handler initiates stop_scan_() but promotion can happen immediately
   // - IDLE: Scanner has already stopped (naturally or by gap_scan_event_handler)
@@ -236,6 +256,7 @@ void ESP32BLETracker::start_scan_(bool first) {
   // Start timeout monitoring in loop() instead of using scheduler
   // This prevents false reboots when the loop is blocked
   this->scan_start_time_ = App.get_loop_component_start_time();
+  this->scan_timeout_ms_ = this->scan_duration_ * 2000;
   this->scan_timeout_state_ = ScanTimeoutState::MONITORING;
 
   esp_err_t err = esp_ble_gap_set_scan_params(&this->scan_params_);
@@ -253,6 +274,10 @@ void ESP32BLETracker::start_scan_(bool first) {
 void ESP32BLETracker::register_client(ESPBTClient *client) {
 #ifdef ESPHOME_ESP32_BLE_TRACKER_CLIENT_COUNT
   client->app_id = ++this->app_id_;
+  // Give client a pointer to our state_version_ so it can notify us of state changes.
+  // This enables loop() fast-path optimization - we skip expensive work when no state changed.
+  // Safe because ESP32BLETracker (singleton) outlives all registered clients.
+  client->set_tracker_state_version(&this->state_version_);
   this->clients_.push_back(client);
   this->recalculate_advertisement_parser_types();
 #endif
@@ -382,6 +407,7 @@ void ESP32BLETracker::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_i
 
 void ESP32BLETracker::set_scanner_state_(ScannerState state) {
   this->scanner_state_ = state;
+  this->state_version_++;
   for (auto *listener : this->scanner_state_listeners_) {
     listener->on_scanner_state(state);
   }

esphome/components/esp32_ble_tracker/esp32_ble_tracker.h

@@ -216,6 +216,19 @@ enum class ConnectionType : uint8_t {
   V3_WITHOUT_CACHE
 };
 
+/// Base class for BLE GATT clients that connect to remote devices.
+///
+/// State Change Tracking Design:
+/// -----------------------------
+/// ESP32BLETracker::loop() needs to know when client states change to avoid
+/// expensive polling. Rather than checking all clients every iteration (~7000/min),
+/// we use a version counter owned by ESP32BLETracker that clients increment on
+/// state changes. The tracker compares versions to skip work when nothing changed.
+///
+/// Ownership: ESP32BLETracker owns state_version_. Clients hold a non-owning
+/// pointer (tracker_state_version_) set during register_client(). Clients
+/// increment the counter through this pointer when their state changes.
+/// The pointer may be null if the client is not registered with a tracker.
 class ESPBTClient : public ESPBTDeviceListener {
  public:
   virtual bool gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
@@ -225,26 +238,49 @@ class ESPBTClient : public ESPBTDeviceListener {
   virtual void disconnect() = 0;
   bool disconnect_pending() const { return this->want_disconnect_; }
   void cancel_pending_disconnect() { this->want_disconnect_ = false; }
+
+  /// Set the client state with IDLE handling (clears want_disconnect_).
+  /// Notifies the tracker of state change for loop optimization.
   virtual void set_state(ClientState st) {
-    this->state_ = st;
+    this->set_state_internal_(st);
     if (st == ClientState::IDLE) {
       this->want_disconnect_ = false;
     }
   }
-  ClientState state() const { return state_; }
+  ClientState state() const { return this->state_; }
+
+  /// Called by ESP32BLETracker::register_client() to enable state change notifications.
+  /// The pointer must remain valid for the lifetime of the client (guaranteed since
+  /// ESP32BLETracker is a singleton that outlives all clients).
+  void set_tracker_state_version(uint8_t *version) { this->tracker_state_version_ = version; }
 
   // Memory optimized layout
   uint8_t app_id;  // App IDs are small integers assigned sequentially
 
  protected:
-  // Group 1: 1-byte types
-  ClientState state_{ClientState::INIT};
+  /// Set state without IDLE handling - use for direct state transitions.
+  /// Increments the tracker's state version counter to signal that loop()
+  /// should do full processing on the next iteration.
+  void set_state_internal_(ClientState st) {
+    this->state_ = st;
+    // Notify tracker that state changed (tracker_state_version_ is owned by ESP32BLETracker)
+    if (this->tracker_state_version_ != nullptr) {
+      (*this->tracker_state_version_)++;
+    }
+  }
+
   // want_disconnect_ is set to true when a disconnect is requested
   // while the client is connecting. This is used to disconnect the
   // client as soon as we get the connection id (conn_id_) from the
   // ESP_GATTC_OPEN_EVT event.
   bool want_disconnect_{false};
-  // 2 bytes used, 2 bytes padding
+
+ private:
+  ClientState state_{ClientState::INIT};
+  /// Non-owning pointer to ESP32BLETracker::state_version_. When this client's
+  /// state changes, we increment the tracker's counter to signal that loop()
+  /// should perform full processing. Null if client not registered with tracker.
+  uint8_t *tracker_state_version_{nullptr};
 };
 
 class ESP32BLETracker : public Component,
@@ -380,6 +416,16 @@ class ESP32BLETracker : public Component,
   // Group 4: 1-byte types (enums, uint8_t, bool)
   uint8_t app_id_{0};
   uint8_t scan_start_fail_count_{0};
+  /// Version counter for loop() fast-path optimization. Incremented when:
+  /// - Scanner state changes (via set_scanner_state_())
+  /// - Any registered client's state changes (clients hold pointer to this counter)
+  /// Owned by this class; clients receive non-owning pointer via register_client().
+  /// When loop() sees state_version_ == last_processed_version_, it skips expensive
+  /// client state counting and takes the fast path (just timeout check + return).
+  uint8_t state_version_{0};
+  /// Last state_version_ value when loop() did full processing. Compared against
+  /// state_version_ to detect if any state changed since last iteration.
+  uint8_t last_processed_version_{0};
   ScannerState scanner_state_{ScannerState::IDLE};
   bool scan_continuous_;
   bool scan_active_;
@@ -396,6 +442,8 @@ class ESP32BLETracker : public Component,
     EXCEEDED_WAIT,  // Timeout exceeded, waiting one loop before reboot
   };
   uint32_t scan_start_time_{0};
+  /// Precomputed timeout value: scan_duration_ * 2000
+  uint32_t scan_timeout_ms_{0};
   ScanTimeoutState scan_timeout_state_{ScanTimeoutState::INACTIVE};
 };
 

esphome/components/esp8266/preferences.cpp

@@ -12,6 +12,7 @@ extern "C" {
 #include "preferences.h"
 
 #include <cstring>
+#include <memory>
 
 namespace esphome::esp8266 {
 
@@ -142,8 +143,16 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
-    uint32_t *buffer = buffer_alloc.get();
+    uint32_t stack_buffer[PREF_BUFFER_WORDS];
+    std::unique_ptr<uint32_t[]> heap_buffer;
+    uint32_t *buffer;
+
+    if (buffer_size <= PREF_BUFFER_WORDS) {
+      buffer = stack_buffer;
+    } else {
+      heap_buffer = make_unique<uint32_t[]>(buffer_size);
+      buffer = heap_buffer.get();
+    }
     memset(buffer, 0, buffer_size * sizeof(uint32_t));
 
     memcpy(buffer, data, len);
@@ -158,8 +167,16 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
-    uint32_t *buffer = buffer_alloc.get();
+    uint32_t stack_buffer[PREF_BUFFER_WORDS];
+    std::unique_ptr<uint32_t[]> heap_buffer;
+    uint32_t *buffer;
+
+    if (buffer_size <= PREF_BUFFER_WORDS) {
+      buffer = stack_buffer;
+    } else {
+      heap_buffer = make_unique<uint32_t[]>(buffer_size);
+      buffer = heap_buffer.get();
+    }
 
     bool ret = this->in_flash ? load_from_flash(this->offset, buffer, buffer_size)
                               : load_from_rtc(this->offset, buffer, buffer_size);

esphome/components/json/__init__.py

@@ -1,6 +1,6 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.core import CoroPriority, coroutine_with_priority
+from esphome.core import CORE, CoroPriority, coroutine_with_priority
 
 CODEOWNERS = ["@esphome/core"]
 json_ns = cg.esphome_ns.namespace("json")
@@ -12,6 +12,11 @@ CONFIG_SCHEMA = cv.All(
 
 @coroutine_with_priority(CoroPriority.BUS)
 async def to_code(config):
-    cg.add_library("bblanchon/ArduinoJson", "7.4.2")
+    if CORE.is_esp32:
+        from esphome.components.esp32 import add_idf_component
+
+        add_idf_component(name="bblanchon/arduinojson", ref="7.4.2")
+    else:
+        cg.add_library("bblanchon/ArduinoJson", "7.4.2")
     cg.add_define("USE_JSON")
     cg.add_global(json_ns.using)

esphome/components/libretiny/__init__.py

@@ -382,4 +382,11 @@ async def component_to_code(config):
             "custom_options.sys_config#h", _BK7231N_SYS_CONFIG_OPTIONS
         )
 
+    # Disable LWIP statistics to save RAM - not needed in production
+    # Must explicitly disable all sub-stats to avoid redefinition warnings
+    cg.add_platformio_option(
+        "custom_options.lwip",
+        ["LWIP_STATS=0", "MEM_STATS=0", "MEMP_STATS=0"],
+    )
+
     await cg.register_component(var, config)

esphome/components/libretiny/preferences.cpp

@@ -166,8 +166,8 @@ class LibreTinyPreferences : public ESPPreferences {
       return true;
     }
 
-    // Allocate buffer on heap to avoid stack allocation for large data
-    auto stored_data = std::make_unique<uint8_t[]>(kv.value_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(kv.value_len);
     fdb_blob_make(&this->blob, stored_data.get(), kv.value_len);
     size_t actual_len = fdb_kv_get_blob(db, key_str, &this->blob);
     if (actual_len != kv.value_len) {

esphome/components/logger/logger.cpp

@@ -1,8 +1,5 @@
 #include "logger.h"
 #include <cinttypes>
-#ifdef USE_ESPHOME_TASK_LOG_BUFFER
-#include <memory>  // For unique_ptr
-#endif
 
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
@@ -199,7 +196,8 @@ inline uint8_t Logger::level_for(const char *tag) {
 
 Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate), tx_buffer_size_(tx_buffer_size) {
   // add 1 to buffer size for null terminator
-  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];  // NOLINT
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)
   this->main_task_ = xTaskGetCurrentTaskHandle();
 #elif defined(USE_ZEPHYR)
@@ -212,11 +210,14 @@ Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate
 void Logger::init_log_buffer(size_t total_buffer_size) {
 #ifdef USE_HOST
   // Host uses slot count instead of byte size
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferHost>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferHost(total_buffer_size);
 #elif defined(USE_ESP32)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBuffer>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBuffer(total_buffer_size);
 #elif defined(USE_LIBRETINY)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferLibreTiny>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferLibreTiny(total_buffer_size);
 #endif
 
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)

esphome/components/logger/logger.h

@@ -412,11 +412,11 @@ class Logger : public Component {
 #endif
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
 #ifdef USE_HOST
-  std::unique_ptr<logger::TaskLogBufferHost> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferHost *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_ESP32)
-  std::unique_ptr<logger::TaskLogBuffer> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBuffer *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_LIBRETINY)
-  std::unique_ptr<logger::TaskLogBufferLibreTiny> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferLibreTiny *log_buffer_{nullptr};  // Allocated once, never freed
 #endif
 #endif
 

esphome/components/mdns/mdns_esp32.cpp

@@ -24,13 +24,14 @@ static void register_esp32(MDNSComponent *comp, StaticVector<MDNSService, MDNS_S
   mdns_instance_name_set(hostname);
 
   for (const auto &service : services) {
-    auto txt_records = std::make_unique<mdns_txt_item_t[]>(service.txt_records.size());
+    // Stack buffer for up to 16 txt records, heap fallback for more
+    SmallBufferWithHeapFallback<16, mdns_txt_item_t> txt_records(service.txt_records.size());
     for (size_t i = 0; i < service.txt_records.size(); i++) {
       const auto &record = service.txt_records[i];
       // key and value are either compile-time string literals in flash or pointers to dynamic_txt_values_
       // Both remain valid for the lifetime of this function, and ESP-IDF makes internal copies
-      txt_records[i].key = MDNS_STR_ARG(record.key);
-      txt_records[i].value = MDNS_STR_ARG(record.value);
+      txt_records.get()[i].key = MDNS_STR_ARG(record.key);
+      txt_records.get()[i].value = MDNS_STR_ARG(record.value);
     }
     uint16_t port = const_cast<TemplatableValue<uint16_t> &>(service.port).value();
     err = mdns_service_add(nullptr, MDNS_STR_ARG(service.service_type), MDNS_STR_ARG(service.proto), port,

esphome/components/sensor/__init__.py

@@ -9,6 +9,7 @@ from esphome.const import (
     CONF_ABOVE,
     CONF_ACCURACY_DECIMALS,
     CONF_ALPHA,
+    CONF_BASELINE,
     CONF_BELOW,
     CONF_CALIBRATION,
     CONF_DEVICE_CLASS,
@@ -38,7 +39,6 @@ from esphome.const import (
     CONF_TIMEOUT,
     CONF_TO,
     CONF_TRIGGER_ID,
-    CONF_TYPE,
     CONF_UNIT_OF_MEASUREMENT,
     CONF_VALUE,
     CONF_WEB_SERVER,
@@ -107,7 +107,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
 from esphome.core.entity_helpers import entity_duplicate_validator, setup_entity
-from esphome.cpp_generator import MockObjClass
+from esphome.cpp_generator import MockObj, MockObjClass
 from esphome.util import Registry
 
 CODEOWNERS = ["@esphome/core"]
@@ -574,38 +574,56 @@ async def lambda_filter_to_code(config, filter_id):
     return automation.new_lambda_pvariable(filter_id, lambda_, StatelessLambdaFilter)
 
 
-DELTA_SCHEMA = cv.Schema(
-    {
-        cv.Required(CONF_VALUE): cv.positive_float,
-        cv.Optional(CONF_TYPE, default="absolute"): cv.one_of(
-            "absolute", "percentage", lower=True
-        ),
-    }
+def validate_delta_value(value):
+    if isinstance(value, str) and value.endswith("%"):
+        # Check it's a well-formed percentage, but return the string as-is
+        try:
+            cv.positive_float(value[:-1])
+            return value
+        except cv.Invalid as exc:
+            raise cv.Invalid("Malformed delta % value") from exc
+    return cv.positive_float(value)
+
+
+# This ideally would be done with `cv.maybe_simple_value` but it doesn't seem to respect the default for min_value.
+DELTA_SCHEMA = cv.Any(
+    cv.All(
+        {
+            # Ideally this would be 'default=float("inf")' but it doesn't translate well to C++
+            cv.Optional(CONF_MAX_VALUE): validate_delta_value,
+            cv.Optional(CONF_MIN_VALUE, default="0.0"): validate_delta_value,
+            cv.Optional(CONF_BASELINE): cv.templatable(cv.float_),
+        },
+        cv.has_at_least_one_key(CONF_MAX_VALUE, CONF_MIN_VALUE),
+    ),
+    validate_delta_value,
 )
 
 
-def validate_delta(config):
-    try:
-        value = cv.positive_float(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "absolute"})
-    except cv.Invalid:
-        pass
-    try:
-        value = cv.percentage(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "percentage"})
-    except cv.Invalid:
-        pass
-    raise cv.Invalid("Delta filter requires a positive number or percentage value.")
+def _get_delta(value):
+    if isinstance(value, str):
+        assert value.endswith("%")
+        return 0.0, float(value[:-1])
+    return value, 0.0
 
 
-@FILTER_REGISTRY.register("delta", DeltaFilter, cv.Any(DELTA_SCHEMA, validate_delta))
+@FILTER_REGISTRY.register("delta", DeltaFilter, DELTA_SCHEMA)
 async def delta_filter_to_code(config, filter_id):
-    percentage = config[CONF_TYPE] == "percentage"
-    return cg.new_Pvariable(
-        filter_id,
-        config[CONF_VALUE],
-        percentage,
-    )
+    # The config could be just the min_value, or it could be a dict.
+    max = MockObj("std::numeric_limits<float>::infinity()"), 0
+    if isinstance(config, dict):
+        min = _get_delta(config[CONF_MIN_VALUE])
+        if CONF_MAX_VALUE in config:
+            max = _get_delta(config[CONF_MAX_VALUE])
+    else:
+        min = _get_delta(config)
+    var = cg.new_Pvariable(filter_id, *min, *max)
+    if isinstance(config, dict) and (baseline_lambda := config.get(CONF_BASELINE)):
+        baseline = await cg.process_lambda(
+            baseline_lambda, [(float, "x")], return_type=float
+        )
+        cg.add(var.set_baseline(baseline))
+    return var
 
 
 @FILTER_REGISTRY.register("or", OrFilter, validate_filters)

esphome/components/sensor/filter.cpp

@@ -291,22 +291,27 @@ optional<float> ThrottleWithPriorityFilter::new_value(float value) {
 }
 
 // DeltaFilter
-DeltaFilter::DeltaFilter(float delta, bool percentage_mode)
-    : delta_(delta), current_delta_(delta), last_value_(NAN), percentage_mode_(percentage_mode) {}
+DeltaFilter::DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1)
+    : min_a0_(min_a0), min_a1_(min_a1), max_a0_(max_a0), max_a1_(max_a1) {}
+
+void DeltaFilter::set_baseline(float (*fn)(float)) { this->baseline_ = fn; }
+
 optional<float> DeltaFilter::new_value(float value) {
-  if (std::isnan(value)) {
-    if (std::isnan(this->last_value_)) {
-      return {};
-    } else {
-      return this->last_value_ = value;
-    }
+  // Always yield the first value.
+  if (std::isnan(this->last_value_)) {
+    this->last_value_ = value;
+    return value;
   }
-  float diff = fabsf(value - this->last_value_);
-  if (std::isnan(this->last_value_) || (diff > 0.0f && diff >= this->current_delta_)) {
-    if (this->percentage_mode_) {
-      this->current_delta_ = fabsf(value * this->delta_);
-    }
-    return this->last_value_ = value;
+  // calculate min and max using the linear equation
+  float ref = this->baseline_(this->last_value_);
+  float min = fabsf(this->min_a0_ + ref * this->min_a1_);
+  float max = fabsf(this->max_a0_ + ref * this->max_a1_);
+  float delta = fabsf(value - ref);
+  // if there is no reference, e.g. for the first value, just accept this one,
+  // otherwise accept only if within range.
+  if (delta > min && delta <= max) {
+    this->last_value_ = value;
+    return value;
   }
   return {};
 }

esphome/components/sensor/filter.h

@@ -452,15 +452,21 @@ class HeartbeatFilter : public Filter, public Component {
 
 class DeltaFilter : public Filter {
  public:
-  explicit DeltaFilter(float delta, bool percentage_mode);
+  explicit DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1);
+
+  void set_baseline(float (*fn)(float));
 
   optional<float> new_value(float value) override;
 
  protected:
-  float delta_;
-  float current_delta_;
+  // These values represent linear equations for the min and max values but in practice only one of a0 and a1 will be
+  // non-zero Each limit is calculated as fabs(a0 + value * a1)
+
+  float min_a0_, min_a1_, max_a0_, max_a1_;
+  // default baseline is the previous value
+  float (*baseline_)(float) = [](float last_value) { return last_value; };
+
   float last_value_{NAN};
-  bool percentage_mode_;
 };
 
 class OrFilter : public Filter {

esphome/components/web_server_idf/web_server_idf.cpp

@@ -487,7 +487,7 @@ void AsyncEventSource::deferrable_send_state(void *source, const char *event_typ
 AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *request,
                                                    esphome::web_server_idf::AsyncEventSource *server,
                                                    esphome::web_server::WebServer *ws)
-    : server_(server), web_server_(ws), entities_iterator_(new esphome::web_server::ListEntitiesIterator(ws, server)) {
+    : server_(server), web_server_(ws), entities_iterator_(ws, server) {
   httpd_req_t *req = *request;
 
   httpd_resp_set_status(req, HTTPD_200);
@@ -531,12 +531,12 @@ AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *
   }
 #endif
 
-  this->entities_iterator_->begin(ws->include_internal_);
+  this->entities_iterator_.begin(ws->include_internal_);
 
   // just dump them all up-front and take advantage of the deferred queue
   //     on second thought that takes too long, but leaving the commented code here for debug purposes
-  // while(!this->entities_iterator_->completed()) {
-  //  this->entities_iterator_->advance();
+  // while(!this->entities_iterator_.completed()) {
+  //  this->entities_iterator_.advance();
   //}
 }
 
@@ -634,8 +634,8 @@ void AsyncEventSourceResponse::process_buffer_() {
 void AsyncEventSourceResponse::loop() {
   process_buffer_();
   process_deferred_queue_();
-  if (!this->entities_iterator_->completed())
-    this->entities_iterator_->advance();
+  if (!this->entities_iterator_.completed())
+    this->entities_iterator_.advance();
 }
 
 bool AsyncEventSourceResponse::try_send_nodefer(const char *message, const char *event, uint32_t id,
@@ -781,7 +781,7 @@ void AsyncEventSourceResponse::deferrable_send_state(void *source, const char *e
                                                      message_generator_t *message_generator) {
   // allow all json "details_all" to go through before publishing bare state events, this avoids unnamed entries showing
   // up in the web GUI and reduces event load during initial connect
-  if (!entities_iterator_->completed() && 0 != strcmp(event_type, "state_detail_all"))
+  if (!this->entities_iterator_.completed() && 0 != strcmp(event_type, "state_detail_all"))
     return;
 
   if (source == nullptr)

esphome/components/web_server_idf/web_server_idf.h

@@ -13,11 +13,14 @@
 #include <utility>
 #include <vector>
 
+#ifdef USE_WEBSERVER
+#include "esphome/components/web_server/list_entities.h"
+#endif
+
 namespace esphome {
 #ifdef USE_WEBSERVER
 namespace web_server {
 class WebServer;
-class ListEntitiesIterator;
 };  // namespace web_server
 #endif
 namespace web_server_idf {
@@ -284,7 +287,7 @@ class AsyncEventSourceResponse {
   std::atomic<int> fd_{};
   std::vector<DeferredEvent> deferred_queue_;
   esphome::web_server::WebServer *web_server_;
-  std::unique_ptr<esphome::web_server::ListEntitiesIterator> entities_iterator_;
+  esphome::web_server::ListEntitiesIterator entities_iterator_;
   std::string event_buffer_{""};
   size_t event_bytes_sent_;
   uint16_t consecutive_send_failures_{0};

esphome/components/wifi/wifi_component_esp8266.cpp

@@ -920,7 +920,16 @@ bssid_t WiFiComponent::wifi_bssid() {
   }
   return bssid;
 }
-std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+std::string WiFiComponent::wifi_ssid() {
+  struct station_config conf {};
+  if (!wifi_station_get_config(&conf)) {
+    return "";
+  }
+  // conf.ssid is uint8[32], not null-terminated if full
+  auto *ssid_s = reinterpret_cast<const char *>(conf.ssid);
+  size_t len = strnlen(ssid_s, sizeof(conf.ssid));
+  return {ssid_s, len};
+}
 const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
   struct station_config conf {};
   if (!wifi_station_get_config(&conf)) {
@@ -934,16 +943,24 @@ const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer
   return buffer.data();
 }
 int8_t WiFiComponent::wifi_rssi() {
-  if (WiFi.status() != WL_CONNECTED)
+  if (wifi_station_get_connect_status() != STATION_GOT_IP)
     return WIFI_RSSI_DISCONNECTED;
-  int8_t rssi = WiFi.RSSI();
+  sint8 rssi = wifi_station_get_rssi();
   // Values >= 31 are error codes per NONOS SDK API, not valid RSSI readings
   return rssi >= 31 ? WIFI_RSSI_DISCONNECTED : rssi;
 }
-int32_t WiFiComponent::get_wifi_channel() { return WiFi.channel(); }
-network::IPAddress WiFiComponent::wifi_subnet_mask_() { return {(const ip_addr_t *) WiFi.subnetMask()}; }
-network::IPAddress WiFiComponent::wifi_gateway_ip_() { return {(const ip_addr_t *) WiFi.gatewayIP()}; }
-network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return {(const ip_addr_t *) WiFi.dnsIP(num)}; }
+int32_t WiFiComponent::get_wifi_channel() { return wifi_get_channel(); }
+network::IPAddress WiFiComponent::wifi_subnet_mask_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.netmask);
+}
+network::IPAddress WiFiComponent::wifi_gateway_ip_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.gw);
+}
+network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return network::IPAddress(dns_getserver(num)); }
 void WiFiComponent::wifi_loop_() {}
 
 }  // namespace esphome::wifi

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -827,16 +827,17 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     }
 
     uint16_t number = it.number;
-    auto records = std::make_unique<wifi_ap_record_t[]>(number);
-    err = esp_wifi_scan_get_ap_records(&number, records.get());
-    if (err != ESP_OK) {
-      ESP_LOGW(TAG, "esp_wifi_scan_get_ap_records failed: %s", esp_err_to_name(err));
-      return;
-    }
-
     scan_result_.init(number);
-    for (int i = 0; i < number; i++) {
-      auto &record = records[i];
+
+    // Process one record at a time to avoid large buffer allocation
+    wifi_ap_record_t record;
+    for (uint16_t i = 0; i < number; i++) {
+      err = esp_wifi_scan_get_ap_record(&record);
+      if (err != ESP_OK) {
+        ESP_LOGW(TAG, "esp_wifi_scan_get_ap_record failed: %s", esp_err_to_name(err));
+        esp_wifi_clear_ap_list();  // Free remaining records not yet retrieved
+        break;
+      }
       bssid_t bssid;
       std::copy(record.bssid, record.bssid + 6, bssid.begin());
       std::string ssid(reinterpret_cast<const char *>(record.ssid));

esphome/const.py

@@ -1379,6 +1379,7 @@ KEY_FRAMEWORK_VERSION = "framework_version"
 KEY_NAME = "name"
 KEY_VARIANT = "variant"
 KEY_PAST_SAFE_MODE = "past_safe_mode"
+KEY_NATIVE_IDF = "native_idf"
 
 # Entity categories
 ENTITY_CATEGORY_NONE = ""

esphome/core/__init__.py

@@ -17,6 +17,7 @@ from esphome.const import (
     CONF_WEB_SERVER,
     CONF_WIFI,
     KEY_CORE,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_BK72XX,
@@ -763,6 +764,9 @@ class EsphomeCore:
 
     @property
     def firmware_bin(self) -> Path:
+        # Check if using native ESP-IDF build (--native-idf)
+        if self.data.get(KEY_NATIVE_IDF, False):
+            return self.relative_build_path("build", f"{self.name}.bin")
         if self.is_libretiny:
             return self.relative_pioenvs_path(self.name, "firmware.uf2")
         return self.relative_pioenvs_path(self.name, "firmware.bin")

esphome/core/component.cpp

@@ -47,18 +47,21 @@ struct ComponentPriorityOverride {
 };
 
 // Error messages for failed components
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
+// This is never freed as error messages persist for the lifetime of the device
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentErrorMessage>> component_error_messages;
+std::vector<ComponentErrorMessage> *component_error_messages = nullptr;
 // Setup priority overrides - freed after setup completes
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentPriorityOverride>> setup_priority_overrides;
+std::vector<ComponentPriorityOverride> *setup_priority_overrides = nullptr;
 
 // Helper to store error messages - reduces duplication between deprecated and new API
 // Remove before 2026.6.0 when deprecated const char* API is removed
 void store_component_error_message(const Component *component, const char *message, bool is_flash_ptr) {
   // Lazy allocate the error messages vector if needed
   if (!component_error_messages) {
-    component_error_messages = std::make_unique<std::vector<ComponentErrorMessage>>();
+    component_error_messages = new std::vector<ComponentErrorMessage>();
   }
   // Check if this component already has an error message
   for (auto &entry : *component_error_messages) {
@@ -467,7 +470,7 @@ float Component::get_actual_setup_priority() const {
 void Component::set_setup_priority(float priority) {
   // Lazy allocate the vector if needed
   if (!setup_priority_overrides) {
-    setup_priority_overrides = std::make_unique<std::vector<ComponentPriorityOverride>>();
+    setup_priority_overrides = new std::vector<ComponentPriorityOverride>();
     // Reserve some space to avoid reallocations (most configs have < 10 overrides)
     setup_priority_overrides->reserve(10);
   }
@@ -553,7 +556,8 @@ WarnIfComponentBlockingGuard::~WarnIfComponentBlockingGuard() {}
 
 void clear_setup_priority_overrides() {
   // Free the setup priority map completely
-  setup_priority_overrides.reset();
+  delete setup_priority_overrides;
+  setup_priority_overrides = nullptr;
 }
 
 }  // namespace esphome

esphome/core/helpers.h

@@ -572,6 +572,10 @@ template<typename T> constexpr T convert_little_endian(T val) {
 bool str_equals_case_insensitive(const std::string &a, const std::string &b);
 /// Compare StringRefs for equality in case-insensitive manner.
 bool str_equals_case_insensitive(StringRef a, StringRef b);
+/// Compare C strings for equality in case-insensitive manner (no heap allocation).
+inline bool str_equals_case_insensitive(const char *a, const char *b) { return strcasecmp(a, b) == 0; }
+inline bool str_equals_case_insensitive(const std::string &a, const char *b) { return strcasecmp(a.c_str(), b) == 0; }
+inline bool str_equals_case_insensitive(const char *a, const std::string &b) { return strcasecmp(a, b.c_str()) == 0; }
 
 /// Check whether a string starts with a value.
 bool str_startswith(const std::string &str, const std::string &start);
@@ -1347,16 +1351,30 @@ template<typename... X> class LazyCallbackManager;
  *
  * Memory overhead comparison (32-bit systems):
  * - CallbackManager: 12 bytes (empty std::vector)
- * - LazyCallbackManager: 4 bytes (nullptr unique_ptr)
+ * - LazyCallbackManager: 4 bytes (nullptr pointer)
+ *
+ * Uses plain pointer instead of unique_ptr to avoid template instantiation overhead.
+ * The class is explicitly non-copyable/non-movable for Rule of Five compliance.
  *
  * @tparam Ts The arguments for the callbacks, wrapped in void().
  */
 template<typename... Ts> class LazyCallbackManager<void(Ts...)> {
  public:
+  LazyCallbackManager() = default;
+  /// Destructor - clean up allocated CallbackManager if any.
+  /// In practice this never runs (entities live for device lifetime) but included for correctness.
+  ~LazyCallbackManager() { delete this->callbacks_; }
+
+  // Non-copyable and non-movable (entities are never copied or moved)
+  LazyCallbackManager(const LazyCallbackManager &) = delete;
+  LazyCallbackManager &operator=(const LazyCallbackManager &) = delete;
+  LazyCallbackManager(LazyCallbackManager &&) = delete;
+  LazyCallbackManager &operator=(LazyCallbackManager &&) = delete;
+
   /// Add a callback to the list. Allocates the underlying CallbackManager on first use.
   void add(std::function<void(Ts...)> &&callback) {
     if (!this->callbacks_) {
-      this->callbacks_ = make_unique<CallbackManager<void(Ts...)>>();
+      this->callbacks_ = new CallbackManager<void(Ts...)>();
     }
     this->callbacks_->add(std::move(callback));
   }
@@ -1378,7 +1396,7 @@ template<typename... Ts> class LazyCallbackManager<void(Ts...)> {
   void operator()(Ts... args) { this->call(args...); }
 
  protected:
-  std::unique_ptr<CallbackManager<void(Ts...)>> callbacks_;
+  CallbackManager<void(Ts...)> *callbacks_{nullptr};
 };
 
 /// Helper class to deduplicate items in a series of values.

esphome/core/time.cpp

@@ -67,7 +67,7 @@ std::string ESPTime::strftime(const char *format) {
 
 std::string ESPTime::strftime(const std::string &format) { return this->strftime(format.c_str()); }
 
-bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+bool ESPTime::strptime(const char *time_to_parse, size_t len, ESPTime &esp_time) {
   uint16_t year;
   uint8_t month;
   uint8_t day;
@@ -75,40 +75,41 @@ bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
   uint8_t minute;
   uint8_t second;
   int num;
+  const int ilen = static_cast<int>(len);
 
-  if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-             &hour,                                                                                      // NOLINT
-             &minute,                                                                                    // NOLINT
-             &second, &num) == 6 &&                                                                      // NOLINT
-      num == static_cast<int>(time_to_parse.size())) {
+  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.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-                    &hour,                                                                               // NOLINT
-                    &minute, &num) == 5 &&                                                               // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } 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.c_str(), "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } 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.c_str(), "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } 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.c_str(), "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } 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;

esphome/core/time.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <cstdlib>
+#include <cstring>
 #include <ctime>
 #include <span>
 #include <string>
@@ -80,11 +81,20 @@ struct ESPTime {
   }
 
   /** Convert a string to ESPTime struct as specified by the format argument.
-   * @param time_to_parse null-terminated c string formatet like this: 2020-08-25 05:30:00.
+   * @param time_to_parse c string formatted like this: 2020-08-25 05:30:00.
+   * @param len length of the string (not including null terminator if present)
    * @param esp_time an instance of a ESPTime struct
-   * @return the success sate of the parsing
+   * @return the success state of the parsing
    */
-  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time);
+  static bool strptime(const char *time_to_parse, size_t len, ESPTime &esp_time);
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const char *time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse, strlen(time_to_parse), esp_time);
+  }
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse.c_str(), time_to_parse.size(), esp_time);
+  }
 
   /// Convert a C tm struct instance with a C unix epoch timestamp to an ESPTime instance.
   static ESPTime from_c_tm(struct tm *c_tm, time_t c_time);

esphome/espidf_api.py

@@ -0,0 +1,229 @@
+"""ESP-IDF direct build API for ESPHome."""
+
+import json
+import logging
+import os
+from pathlib import Path
+import shutil
+import subprocess
+
+from esphome.components.esp32.const import KEY_ESP32, KEY_FLASH_SIZE
+from esphome.const import CONF_COMPILE_PROCESS_LIMIT, CONF_ESPHOME
+from esphome.core import CORE, EsphomeError
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def _get_idf_path() -> Path | None:
+    """Get IDF_PATH from environment or common locations."""
+    # Check environment variable first
+    if "IDF_PATH" in os.environ:
+        path = Path(os.environ["IDF_PATH"])
+        if path.is_dir():
+            return path
+
+    # Check common installation locations
+    common_paths = [
+        Path.home() / "esp" / "esp-idf",
+        Path.home() / ".espressif" / "esp-idf",
+        Path("/opt/esp-idf"),
+    ]
+
+    for path in common_paths:
+        if path.is_dir() and (path / "tools" / "idf.py").is_file():
+            return path
+
+    return None
+
+
+def _get_idf_env() -> dict[str, str]:
+    """Get environment variables needed for ESP-IDF build.
+
+    Requires the user to have sourced export.sh before running esphome.
+    """
+    env = os.environ.copy()
+
+    idf_path = _get_idf_path()
+    if idf_path is None:
+        raise EsphomeError(
+            "ESP-IDF not found. Please install ESP-IDF and source export.sh:\n"
+            "  git clone -b v5.3.2 --recursive https://github.com/espressif/esp-idf.git ~/esp-idf\n"
+            "  cd ~/esp-idf && ./install.sh\n"
+            "  source ~/esp-idf/export.sh\n"
+            "See: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/"
+        )
+
+    env["IDF_PATH"] = str(idf_path)
+    return env
+
+
+def run_idf_py(
+    *args, cwd: Path | None = None, capture_output: bool = False
+) -> int | str:
+    """Run idf.py with the given arguments."""
+    idf_path = _get_idf_path()
+    if idf_path is None:
+        raise EsphomeError("ESP-IDF not found")
+
+    env = _get_idf_env()
+    idf_py = idf_path / "tools" / "idf.py"
+
+    cmd = ["python", str(idf_py)] + list(args)
+
+    if cwd is None:
+        cwd = CORE.build_path
+
+    _LOGGER.debug("Running: %s", " ".join(cmd))
+    _LOGGER.debug("  in directory: %s", cwd)
+
+    if capture_output:
+        result = subprocess.run(
+            cmd,
+            cwd=cwd,
+            env=env,
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if result.returncode != 0:
+            _LOGGER.error("idf.py failed:\n%s", result.stderr)
+        return result.stdout
+    result = subprocess.run(
+        cmd,
+        cwd=cwd,
+        env=env,
+        check=False,
+    )
+    return result.returncode
+
+
+def run_reconfigure() -> int:
+    """Run cmake reconfigure only (no build)."""
+    return run_idf_py("reconfigure")
+
+
+def run_compile(config, verbose: bool) -> int:
+    """Compile the ESP-IDF project.
+
+    Uses two-phase configure to auto-discover available components:
+    1. If no previous build, configure with minimal REQUIRES to discover components
+    2. Regenerate CMakeLists.txt with discovered components
+    3. Run full build
+    """
+    from esphome.build_gen.espidf import has_discovered_components, write_project
+
+    # Check if we need to do discovery phase
+    if not has_discovered_components():
+        _LOGGER.info("Discovering available ESP-IDF components...")
+        write_project(minimal=True)
+        rc = run_reconfigure()
+        if rc != 0:
+            _LOGGER.error("Component discovery failed")
+            return rc
+        _LOGGER.info("Regenerating CMakeLists.txt with discovered components...")
+        write_project(minimal=False)
+
+    # Build
+    args = ["build"]
+
+    if verbose:
+        args.append("-v")
+
+    # Add parallel job limit if configured
+    if CONF_COMPILE_PROCESS_LIMIT in config.get(CONF_ESPHOME, {}):
+        limit = config[CONF_ESPHOME][CONF_COMPILE_PROCESS_LIMIT]
+        args.extend(["-j", str(limit)])
+
+    # Set the sdkconfig file
+    sdkconfig_path = CORE.relative_build_path(f"sdkconfig.{CORE.name}")
+    if sdkconfig_path.is_file():
+        args.extend(["-D", f"SDKCONFIG={sdkconfig_path}"])
+
+    return run_idf_py(*args)
+
+
+def get_firmware_path() -> Path:
+    """Get the path to the compiled firmware binary."""
+    build_dir = CORE.relative_build_path("build")
+    return build_dir / f"{CORE.name}.bin"
+
+
+def get_factory_firmware_path() -> Path:
+    """Get the path to the factory firmware (with bootloader)."""
+    build_dir = CORE.relative_build_path("build")
+    return build_dir / f"{CORE.name}.factory.bin"
+
+
+def create_factory_bin() -> bool:
+    """Create factory.bin by merging bootloader, partition table, and app."""
+    build_dir = CORE.relative_build_path("build")
+    flasher_args_path = build_dir / "flasher_args.json"
+
+    if not flasher_args_path.is_file():
+        _LOGGER.warning("flasher_args.json not found, cannot create factory.bin")
+        return False
+
+    try:
+        with open(flasher_args_path, encoding="utf-8") as f:
+            flash_data = json.load(f)
+    except (json.JSONDecodeError, OSError) as e:
+        _LOGGER.error("Failed to read flasher_args.json: %s", e)
+        return False
+
+    # Get flash size from config
+    flash_size = CORE.data[KEY_ESP32][KEY_FLASH_SIZE]
+
+    # Build esptool merge command
+    sections = []
+    for addr, fname in sorted(
+        flash_data.get("flash_files", {}).items(), key=lambda kv: int(kv[0], 16)
+    ):
+        file_path = build_dir / fname
+        if file_path.is_file():
+            sections.extend([addr, str(file_path)])
+        else:
+            _LOGGER.warning("Flash file not found: %s", file_path)
+
+    if not sections:
+        _LOGGER.warning("No flash sections found")
+        return False
+
+    output_path = get_factory_firmware_path()
+    chip = flash_data.get("extra_esptool_args", {}).get("chip", "esp32")
+
+    cmd = [
+        "python",
+        "-m",
+        "esptool",
+        "--chip",
+        chip,
+        "merge_bin",
+        "--flash_size",
+        flash_size,
+        "--output",
+        str(output_path),
+    ] + sections
+
+    _LOGGER.info("Creating factory.bin...")
+    result = subprocess.run(cmd, capture_output=True, text=True, check=False)
+
+    if result.returncode != 0:
+        _LOGGER.error("Failed to create factory.bin: %s", result.stderr)
+        return False
+
+    _LOGGER.info("Created: %s", output_path)
+    return True
+
+
+def create_ota_bin() -> bool:
+    """Copy the firmware to .ota.bin for ESPHome OTA compatibility."""
+    firmware_path = get_firmware_path()
+    ota_path = firmware_path.with_suffix(".ota.bin")
+
+    if not firmware_path.is_file():
+        _LOGGER.warning("Firmware not found: %s", firmware_path)
+        return False
+
+    shutil.copy(firmware_path, ota_path)
+    _LOGGER.info("Created: %s", ota_path)
+    return True

esphome/idf_component.yml

@@ -1,4 +1,6 @@
 dependencies:
+  bblanchon/arduinojson:
+    version: "7.4.2"
   espressif/esp-tflite-micro:
     version: 1.3.3~1
   espressif/esp32-camera:

platformio.ini

@@ -34,7 +34,6 @@ build_flags =
 [common]
 ; Base dependencies for all environments
 lib_deps_base =
-    bblanchon/ArduinoJson@7.4.2            ; json
     wjtje/qr-code-generator-library@1.7.0  ; qr_code
     functionpointer/arduino-MLX90393@1.0.2 ; mlx90393
     pavlodn/HaierProtocol@0.9.31           ; haier
@@ -111,6 +110,7 @@ platform_packages =
 framework = arduino
 lib_deps =
     ${common:arduino.lib_deps}
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP8266WiFi                           ; wifi (Arduino built-in)
     Update                                ; ota (Arduino built-in)
     ESP32Async/ESPAsyncTCP@2.0.0          ; async_tcp
@@ -201,6 +201,7 @@ platform_packages =
 framework = arduino
 lib_deps =
     ${common:arduino.lib_deps}
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
 build_flags =
     ${common:arduino.build_flags}
@@ -216,6 +217,7 @@ platform = libretiny@1.9.2
 framework = arduino
 lib_compat_mode = soft
 lib_deps =
+    bblanchon/ArduinoJson@7.4.2           ; json
     ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
     droscy/esp_wireguard@0.4.2            ; wireguard
 build_flags =
@@ -239,6 +241,7 @@ build_flags =
     -DUSE_NRF52
 lib_deps =
     ${common.lib_deps_base}
+    bblanchon/ArduinoJson@7.4.2           ; json
 
 ; All the actual environments are defined below.
 

script/ci-custom.py

@@ -732,6 +732,26 @@ def lint_no_heap_allocating_helpers(fname, match):
     )
 
 
+@lint_re_check(
+    # Match sprintf/vsprintf but not snprintf/vsnprintf
+    # [^\w] ensures we don't match the safe variants
+    r"[^\w](v?sprintf)\s*\(" + CPP_RE_EOL,
+    include=cpp_include,
+)
+def lint_no_sprintf(fname, match):
+    func = match.group(1)
+    safe_func = func.replace("sprintf", "snprintf")
+    return (
+        f"{highlight(func + '()')} is not allowed in ESPHome. It has no buffer size limit "
+        f"and can cause buffer overflows.\n"
+        f"Please use one of these alternatives:\n"
+        f"  - {highlight(safe_func + '(buf, sizeof(buf), fmt, ...)')} for general formatting\n"
+        f"  - {highlight('buf_append_printf(buf, sizeof(buf), pos, fmt, ...)')} for "
+        f"offset-based formatting (also stores format strings in flash on ESP8266)\n"
+        f"(If strictly necessary, add `// NOLINT` to the end of the line)"
+    )
+
+
 @lint_content_find_check(
     "ESP_LOG",
     include=["*.h", "*.tcc"],

tests/components/template/common-base.yaml

@@ -121,6 +121,8 @@ sensor:
           min_value: -10.0
       - debounce: 0.1s
       - delta: 5.0
+      - delta:
+          max_value: 2%
       - exponential_moving_average:
           alpha: 0.1
           send_every: 15

tests/integration/fixtures/sensor_filters_delta.yaml

@@ -0,0 +1,180 @@
+esphome:
+  name: test-delta-filters
+
+host:
+api:
+  batch_delay: 0ms  # Disable batching to receive all state updates
+logger:
+  level: DEBUG
+
+sensor:
+  - platform: template
+    name: "Source Sensor 1"
+    id: source_sensor_1
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 2"
+    id: source_sensor_2
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 3"
+    id: source_sensor_3
+    accuracy_decimals: 1
+
+  - platform: template
+    name: "Source Sensor 4"
+    id: source_sensor_4
+    accuracy_decimals: 1
+
+  - platform: copy
+    source_id: source_sensor_1
+    name: "Filter Min"
+    id: filter_min
+    filters:
+      - delta:
+          min_value: 10
+
+  - platform: copy
+    source_id: source_sensor_2
+    name: "Filter Max"
+    id: filter_max
+    filters:
+      - delta:
+          max_value: 10
+
+  - platform: copy
+    source_id: source_sensor_3
+    id: test_3_baseline
+    filters:
+      - median:
+          window_size: 6
+          send_every: 1
+          send_first_at: 1
+
+  - platform: copy
+    source_id: source_sensor_3
+    name: "Filter Baseline Max"
+    id: filter_baseline_max
+    filters:
+      - delta:
+          max_value: 10
+          baseline: !lambda return id(test_3_baseline).state;
+
+  - platform: copy
+    source_id: source_sensor_4
+    name: "Filter Zero Delta"
+    id: filter_zero_delta
+    filters:
+      - delta: 0
+
+script:
+  - id: test_filter_min
+    then:
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 5.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 12.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: 8.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_1
+          state: -2.0
+
+  - id: test_filter_max
+    then:
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 5.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 40.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: 10.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_2
+          state: -40.0  # Filtered out
+
+  - id: test_filter_baseline_max
+    then:
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 2.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 3.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 40.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 20.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_3
+          state: 20.0
+
+  - id: test_filter_zero_delta
+    then:
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 1.0
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 1.0  # Filtered out
+      - delay: 20ms
+      - sensor.template.publish:
+          id: source_sensor_4
+          state: 2.0
+
+button:
+  - platform: template
+    name: "Test Filter Min"
+    id: btn_filter_min
+    on_press:
+      - script.execute: test_filter_min
+
+  - platform: template
+    name: "Test Filter Max"
+    id: btn_filter_max
+    on_press:
+      - script.execute: test_filter_max
+
+  - platform: template
+    name: "Test Filter Baseline Max"
+    id: btn_filter_baseline_max
+    on_press:
+      - script.execute: test_filter_baseline_max
+
+  - platform: template
+    name: "Test Filter Zero Delta"
+    id: btn_filter_zero_delta
+    on_press:
+      - script.execute: test_filter_zero_delta

tests/integration/test_sensor_filters_delta.py

@@ -0,0 +1,163 @@
+"""Test sensor DeltaFilter functionality."""
+
+from __future__ import annotations
+
+import asyncio
+
+from aioesphomeapi import ButtonInfo, EntityState, SensorState
+import pytest
+
+from .state_utils import InitialStateHelper, build_key_to_entity_mapping
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_sensor_filters_delta(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    loop = asyncio.get_running_loop()
+
+    sensor_values: dict[str, list[float]] = {
+        "filter_min": [],
+        "filter_max": [],
+        "filter_baseline_max": [],
+        "filter_zero_delta": [],
+    }
+
+    filter_min_done = loop.create_future()
+    filter_max_done = loop.create_future()
+    filter_baseline_max_done = loop.create_future()
+    filter_zero_delta_done = loop.create_future()
+
+    def on_state(state: EntityState) -> None:
+        if not isinstance(state, SensorState) or state.missing_state:
+            return
+
+        sensor_name = key_to_sensor.get(state.key)
+        if sensor_name not in sensor_values:
+            return
+
+        sensor_values[sensor_name].append(state.state)
+
+        # Check completion conditions
+        if (
+            sensor_name == "filter_min"
+            and len(sensor_values[sensor_name]) == 3
+            and not filter_min_done.done()
+        ):
+            filter_min_done.set_result(True)
+        elif (
+            sensor_name == "filter_max"
+            and len(sensor_values[sensor_name]) == 3
+            and not filter_max_done.done()
+        ):
+            filter_max_done.set_result(True)
+        elif (
+            sensor_name == "filter_baseline_max"
+            and len(sensor_values[sensor_name]) == 4
+            and not filter_baseline_max_done.done()
+        ):
+            filter_baseline_max_done.set_result(True)
+        elif (
+            sensor_name == "filter_zero_delta"
+            and len(sensor_values[sensor_name]) == 2
+            and not filter_zero_delta_done.done()
+        ):
+            filter_zero_delta_done.set_result(True)
+
+    async with (
+        run_compiled(yaml_config),
+        api_client_connected() as client,
+    ):
+        # Get entities and build key mapping
+        entities, _ = await client.list_entities_services()
+        key_to_sensor = build_key_to_entity_mapping(
+            entities,
+            {
+                "filter_min": "Filter Min",
+                "filter_max": "Filter Max",
+                "filter_baseline_max": "Filter Baseline Max",
+                "filter_zero_delta": "Filter Zero Delta",
+            },
+        )
+
+        # Set up initial state helper with all entities
+        initial_state_helper = InitialStateHelper(entities)
+
+        # Subscribe to state changes with wrapper
+        client.subscribe_states(initial_state_helper.on_state_wrapper(on_state))
+
+        # Wait for initial states
+        await initial_state_helper.wait_for_initial_states()
+
+        # Find all buttons
+        button_name_map = {
+            "Test Filter Min": "filter_min",
+            "Test Filter Max": "filter_max",
+            "Test Filter Baseline Max": "filter_baseline_max",
+            "Test Filter Zero Delta": "filter_zero_delta",
+        }
+        buttons = {}
+        for entity in entities:
+            if isinstance(entity, ButtonInfo) and entity.name in button_name_map:
+                buttons[button_name_map[entity.name]] = entity.key
+
+        assert len(buttons) == 4, f"Expected 3 buttons, found {len(buttons)}"
+
+        # Test 1: Min
+        sensor_values["filter_min"].clear()
+        client.button_command(buttons["filter_min"])
+        try:
+            await asyncio.wait_for(filter_min_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(f"Test 1 timed out. Values: {sensor_values['filter_min']}")
+
+        expected = [1.0, 12.0, -2.0]
+        assert sensor_values["filter_min"] == pytest.approx(expected), (
+            f"Test 1 failed: expected {expected}, got {sensor_values['filter_min']}"
+        )
+
+        # Test 2: Max
+        sensor_values["filter_max"].clear()
+        client.button_command(buttons["filter_max"])
+        try:
+            await asyncio.wait_for(filter_max_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(f"Test 2 timed out. Values: {sensor_values['filter_max']}")
+
+        expected = [1.0, 5.0, 10.0]
+        assert sensor_values["filter_max"] == pytest.approx(expected), (
+            f"Test 2 failed: expected {expected}, got {sensor_values['filter_max']}"
+        )
+
+        # Test 3: Baseline Max
+        sensor_values["filter_baseline_max"].clear()
+        client.button_command(buttons["filter_baseline_max"])
+        try:
+            await asyncio.wait_for(filter_baseline_max_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(
+                f"Test 3 timed out. Values: {sensor_values['filter_baseline_max']}"
+            )
+
+        expected = [1.0, 2.0, 3.0, 20.0]
+        assert sensor_values["filter_baseline_max"] == pytest.approx(expected), (
+            f"Test 3 failed: expected {expected}, got {sensor_values['filter_baseline_max']}"
+        )
+
+        # Test 4: Zero Delta
+        sensor_values["filter_zero_delta"].clear()
+        client.button_command(buttons["filter_zero_delta"])
+        try:
+            await asyncio.wait_for(filter_zero_delta_done, timeout=2.0)
+        except TimeoutError:
+            pytest.fail(
+                f"Test 4 timed out. Values: {sensor_values['filter_zero_delta']}"
+            )
+
+        expected = [1.0, 2.0]
+        assert sensor_values["filter_zero_delta"] == pytest.approx(expected), (
+            f"Test 4 failed: expected {expected}, got {sensor_values['filter_zero_delta']}"
+        )