Merge remote-tracking branch 'upstream/master' into feature/mtrr

2026-02-22 09:35:32 -07:00 · 2023-08-06 17:12:01 -04:00
parent 76b19b3ac2 cb24ee27cb
commit 366b492537
427 changed files with 9415 additions and 24870 deletions
--- a/.ci/AppImageBuilder.yml
+++ b/.ci/AppImageBuilder.yml
@@ -57,7 +57,7 @@ AppDir:
    - libqt5gui5 # if QT:BOOL=ON
    - libqt5widgets5 # if QT:BOOL=ON
    - libsixel1 # if CLI:BOOL=ON
-    - libslirp0 # if SLIRP_EXTERNAL:BOOL=ON
+    - libslirp0
    - libsndio7.0 # if OPENAL:BOOL=ON
    - libvdeplug-dev # -dev also pulls in libvdeplug2. -dev is required to get the proper .so symlink to the library
    - libx11-6 # if QT:BOOL=ON
--- a/.ci/build.sh
+++ b/.ci/build.sh
@@ -670,9 +670,6 @@ EOF
 	else
 		echo [-] Not installing dependencies again
 	fi
-
-	# Link against the system libslirp instead of compiling ours.
-	cmake_flags_extra="$cmake_flags_extra -D SLIRP_EXTERNAL=ON"
 fi

 # Point CMake to the toolchain file.
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -263,7 +263,7 @@ jobs:
          build-wrapper-win-x86-64 --out-dir ${{ env.BUILD_WRAPPER_OUT_DIR }} cmake --build build

      - name: Run sonar-scanner
-#        if: 0
+        if: 0
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
@@ -445,7 +445,7 @@ jobs:
          build-wrapper-macosx-x86 --out-dir ${{ env.BUILD_WRAPPER_OUT_DIR }} cmake --build build

      - name: Run sonar-scanner
-#        if: 0
+        if: 0
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,10 +30,6 @@ if(NOT DEFINED OPENAL OR OPENAL)
    list(APPEND VCPKG_MANIFEST_FEATURES "openal")
 endif()

-if(SLIRP_EXTERNAL)
-    list(APPEND VCPKG_MANIFEST_FEATURES "slirp")
-endif()
-
 if(MUNT_EXTERNAL)
    list(APPEND VCPKG_MANIFEST_FEATURES "munt")
 endif()
--- a/README.md
+++ b/README.md
@@ -1,13 +1,15 @@
 86Box
 =====
+
 [![Build Status](https://ci.86box.net/job/86Box/badge/icon)](https://ci.86box.net/job/86Box/)

 **86Box** is a low level x86 emulator that runs older operating systems and software designed for IBM PC systems and compatibles from 1981 through fairly recent system designs based on the PCI bus.

 Features
 --------
+
 * Easy to use interface inspired by mainstream hypervisor software
-* Low level emulation of 8086-based processors up to the Pentium with focus on accuracy
+* Low level emulation of 8086-based processors up to the Mendocino-era Celeron with focus on accuracy
 * Great range of customizability of virtual machines
 * Many available systems, such as the very first IBM PC 5150 from 1981, or the more obscure IBM PS/2 line of systems based on the Micro Channel Architecture
 * Lots of supported peripherals including video adapters, sound cards, network adapters, hard disk controllers, and SCSI adapters
@@ -16,15 +18,17 @@ Features

 Minimum system requirements and recommendations
 -----------------------------------------------
-* Intel Core 2 or AMD Athlon 64 processor
-* Windows version: Windows 7 Service Pack 1, Windows 8.1 or Windows 10
+
+* Intel Core 2 or AMD Athlon 64 processor or newer
+* Windows version: Windows 7 Service Pack 1 or later
 * Linux version: Ubuntu 16.04, Debian 9.0 or other distributions from 2016 onwards
-* macOS version: macOS High Sierra 10.13
-* 4 GB of RAM
+* macOS version: macOS High Sierra 10.13 or newer
+* 4 GB of RAM or higher

 Performance may vary depending on both host and guest configuration. Most emulation logic is executed in a single thread; therefore, systems with better IPC (instructions per clock) generally should be able to emulate higher clock speeds.

 It is also recommended to use a manager application with 86Box for easier handling of multiple virtual machines.
+
 * [86Box Manager](https://github.com/86Box/86BoxManager) by [Overdoze](https://github.com/daviunic) (Windows only)
 * [86Box Manager Lite](https://github.com/insanemal/86box_manager_py) by [Insanemal](https://github.com/insanemal)
 * [WinBox for 86Box](https://github.com/86Box/WinBox-for-86Box) by Laci bá' (Windows only)
@@ -35,10 +39,12 @@ It is also possible to use 86Box on its own with the `--vmpath`/`-P` command lin

 Getting started
 ---------------
+
 See [our documentation](https://86box.readthedocs.io/en/latest/index.html) for an overview of the emulator's features and user interface.

 Community
 ---------
+
 We operate an IRC channel and a Discord server for discussing 86Box, its development and anything related to retro computing. We look forward to hearing from you!

 [![Visit our IRC channel](https://kiwiirc.com/buttons/irc.ringoflightning.net/86Box.png)](https://kiwiirc.com/client/irc.ringoflightning.net/?nick=86box|?#86Box)
@@ -47,16 +53,19 @@ We operate an IRC channel and a Discord server for discussing 86Box, its develop

 Contributions
 ---------
+
 We welcome all contributions to the project, as long as the [contribution guidelines](CONTRIBUTING.md) are followed.

 Licensing
 ---------
+
 86Box is released under the [GNU General Public License, version 2](https://www.gnu.org/licenses/old-licenses/gpl-2.0.html) or later. For more information, see the `COPYING` file in the root of the repository.

 The emulator can also optionally make use of [munt](https://github.com/munt/munt), [FluidSynth](https://www.fluidsynth.org/), [Ghostscript](https://www.ghostscript.com/) and [Discord Game SDK](https://discord.com/developers/docs/game-sdk/sdk-starter-guide), which are distributed under their respective licenses.

 Donations
 ---------
+
 We do not charge you for the emulator but donations are still welcome:
 https://paypal.me/86Box.

--- a/debian/rules
+++ b/debian/rules
@@ -25,7 +25,7 @@ endif
 	dh $@ --buildsystem cmake+ninja

 override_dh_auto_configure:
-	dh_auto_configure --buildsystem cmake+ninja -- --preset regular --toolchain $(TOOLCHAIN) -DNEW_DYNAREC=$(NDR) -DSLIRP_EXTERNAL=on
+	dh_auto_configure --buildsystem cmake+ninja -- --preset regular --toolchain $(TOOLCHAIN) -DNEW_DYNAREC=$(NDR)

 override_dh_auto_test:

--- a/src/86box.c
+++ b/src/86box.c
@@ -408,18 +408,18 @@ pc_log(const char *fmt, ...)
 int
 pc_init(int argc, char *argv[])
 {
-    char      *ppath = NULL;
-    char      *rpath = NULL;
-    char      *cfg = NULL;
-    char      *p;
-    char       temp[2048];
-    char      *fn[FDD_NUM] = { NULL };
-    char       drive = 0;
-    char      *temp2 = NULL;
-    struct tm *info;
-    time_t     now;
-    int        c;
-    int        lvmp = 0;
+    char            *ppath = NULL;
+    char            *rpath = NULL;
+    char            *cfg = NULL;
+    char            *p;
+    char             temp[2048];
+    char            *fn[FDD_NUM] = { NULL };
+    char             drive = 0;
+    char            *temp2 = NULL;
+    const struct tm *info;
+    time_t           now;
+    int              c;
+    int              lvmp = 0;
 #ifdef ENABLE_NG
    int ng = 0;
 #endif
@@ -1144,9 +1144,9 @@ pc_reset_hard_init(void)
 void
 update_mouse_msg(void)
 {
-    wchar_t wcpufamily[2048];
-    wchar_t wcpu[2048];
-    wchar_t wmachine[2048];
+    wchar_t  wcpufamily[2048];
+    wchar_t  wcpu[2048];
+    wchar_t  wmachine[2048];
    wchar_t *wcp;

    mbstowcs(wmachine, machine_getname(), strlen(machine_getname()) + 1);
@@ -1185,7 +1185,7 @@ pc_reset_hard(void)
 }

 void
-pc_close(thread_t *ptr)
+pc_close(UNUSED(thread_t *ptr))
 {
    /* Wait a while so things can shut down. */
    plat_delay_ms(200);
--- a/src/acpi.c
+++ b/src/acpi.c
@@ -226,10 +226,10 @@ acpi_reg_read_common_regs(UNUSED(int size), uint16_t addr, void *priv)
 static uint32_t
 acpi_reg_read_ali(int size, uint16_t addr, void *priv)
 {
-    acpi_t  *dev = (acpi_t *) priv;
-    uint32_t ret = 0x00000000;
-    int      shift16;
-    int      shift32;
+    const acpi_t  *dev = (acpi_t *) priv;
+    uint32_t       ret = 0x00000000;
+    int            shift16;
+    int            shift32;

    addr &= 0x3f;
    shift16 = (addr & 1) << 3;
@@ -294,10 +294,10 @@ acpi_reg_read_ali(int size, uint16_t addr, void *priv)
 static uint32_t
 acpi_reg_read_intel(int size, uint16_t addr, void *priv)
 {
-    acpi_t  *dev = (acpi_t *) priv;
-    uint32_t ret = 0x00000000;
-    int      shift16;
-    int      shift32;
+    const acpi_t  *dev = (acpi_t *) priv;
+    uint32_t       ret = 0x00000000;
+    int            shift16;
+    int            shift32;

    addr &= 0x3f;
    shift16 = (addr & 1) << 3;
@@ -391,10 +391,10 @@ acpi_reg_read_intel(int size, uint16_t addr, void *priv)
 static uint32_t
 acpi_reg_read_via_common(int size, uint16_t addr, void *priv)
 {
-    acpi_t  *dev = (acpi_t *) priv;
-    uint32_t ret = 0x00000000;
-    int      shift16;
-    int      shift32;
+    const acpi_t  *dev = (acpi_t *) priv;
+    uint32_t       ret = 0x00000000;
+    int            shift16;
+    int            shift32;

    addr &= 0xff;
    shift16 = (addr & 1) << 3;
@@ -544,10 +544,10 @@ acpi_reg_read_via(int size, uint16_t addr, void *priv)
 static uint32_t
 acpi_reg_read_via_596b(int size, uint16_t addr, void *priv)
 {
-    acpi_t  *dev = (acpi_t *) priv;
-    uint32_t ret = 0x00000000;
-    int      shift16;
-    int      shift32;
+    const acpi_t  *dev = (acpi_t *) priv;
+    uint32_t       ret = 0x00000000;
+    int            shift16;
+    int            shift32;

    addr &= 0x7f;
    shift16 = (addr & 1) << 3;
@@ -610,9 +610,9 @@ acpi_reg_read_smc(int size, uint16_t addr, void *priv)
 static uint32_t
 acpi_aux_reg_read_smc(UNUSED(int size), uint16_t addr, void *priv)
 {
-    acpi_t  *dev = (acpi_t *) priv;
-    uint32_t ret = 0x00000000;
-    int      shift16;
+    const acpi_t  *dev = (acpi_t *) priv;
+    uint32_t       ret = 0x00000000;
+    int            shift16;

    addr &= 0x07;
    shift16 = (addr & 1) << 3;
@@ -1189,7 +1189,7 @@ acpi_aux_reg_write_smc(UNUSED(int size), uint16_t addr, uint8_t val, void *priv)
 static uint32_t
 acpi_reg_read_common(int size, uint16_t addr, void *priv)
 {
-    acpi_t *dev = (acpi_t *) priv;
+    const acpi_t *dev = (acpi_t *) priv;
    uint8_t ret = 0xff;

    if (dev->vendor == VEN_ALI)
@@ -1209,7 +1209,7 @@ acpi_reg_read_common(int size, uint16_t addr, void *priv)
 static void
 acpi_reg_write_common(int size, uint16_t addr, uint8_t val, void *priv)
 {
-    acpi_t *dev = (acpi_t *) priv;
+    const acpi_t *dev = (acpi_t *) priv;

    if (dev->vendor == VEN_ALI)
        acpi_reg_write_ali(size, addr, val, priv);
@@ -1226,7 +1226,7 @@ acpi_reg_write_common(int size, uint16_t addr, uint8_t val, void *priv)
 static uint32_t
 acpi_aux_reg_read_common(int size, uint16_t addr, void *priv)
 {
-    acpi_t *dev = (acpi_t *) priv;
+    const acpi_t *dev = (acpi_t *) priv;
    uint8_t ret = 0xff;

    if (dev->vendor == VEN_SMC)
@@ -1238,7 +1238,7 @@ acpi_aux_reg_read_common(int size, uint16_t addr, void *priv)
 static void
 acpi_aux_reg_write_common(int size, uint16_t addr, uint8_t val, void *priv)
 {
-    acpi_t *dev = (acpi_t *) priv;
+    const acpi_t *dev = (acpi_t *) priv;

    if (dev->vendor == VEN_SMC)
        acpi_aux_reg_write_smc(size, addr, val, priv);
@@ -1591,8 +1591,8 @@ acpi_apm_out(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 acpi_apm_in(uint16_t port, void *priv)
 {
-    acpi_t *dev = (acpi_t *) priv;
-    uint8_t ret = 0xff;
+    const acpi_t *dev = (acpi_t *) priv;
+    uint8_t       ret = 0xff;

    port &= 0x0001;

@@ -1694,7 +1694,7 @@ acpi_init(const device_t *info)

    dev = (acpi_t *) malloc(sizeof(acpi_t));
    if (dev == NULL)
-        return (NULL);
+        return NULL;
    memset(dev, 0x00, sizeof(acpi_t));

    cpu_to_acpi = ACPI_TIMER_FREQ / cpuclock;
@@ -1723,6 +1723,7 @@ acpi_init(const device_t *info)
            dev->suspend_types[2] = SUS_SUSPEND | SUS_NVR | SUS_RESET_CPU | SUS_RESET_PCI;
            dev->suspend_types[3] = SUS_SUSPEND;
            dev->suspend_types[5] = SUS_POWER_OFF; /* undocumented, used for S4/S5 by ASUS P5A ACPI table */
+            dev->suspend_types[7] = SUS_POWER_OFF; /* undocumented, used for S5 by Gigabyte GA-5AX ACPI table */
            break;

        case VEN_VIA:
--- a/src/apm.c
+++ b/src/apm.c
@@ -71,8 +71,8 @@ apm_out(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 apm_in(uint16_t port, void *priv)
 {
-    apm_t  *dev = (apm_t *) priv;
-    uint8_t ret = 0xff;
+    const apm_t  *dev = (apm_t *) priv;
+    uint8_t       ret = 0xff;

    port &= 0x0001;

@@ -102,9 +102,8 @@ apm_close(void *priv)
    free(dev);
 }

-static void
-    *
-    apm_init(const device_t *info)
+static void *
+apm_init(const device_t *info)
 {
    apm_t *dev = (apm_t *) malloc(sizeof(apm_t));
    memset(dev, 0, sizeof(apm_t));
--- a/src/cdrom/cdrom.c
+++ b/src/cdrom/cdrom.c
@@ -163,7 +163,7 @@ cdrom_interface_get_from_internal_name(char *s)
    int c = 0;

    while (controllers[c].device != NULL) {
-        if (!strcmp((char *) controllers[c].device->internal_name, s))
+        if (!strcmp(controllers[c].device->internal_name, s))
            return c;
        c++;
    }
--- a/src/cdrom/cdrom_image_backend.c
+++ b/src/cdrom/cdrom_image_backend.c
@@ -202,7 +202,7 @@ track_file_close(track_t *trk)
 static void
 cdi_clear_tracks(cd_img_t *cdi)
 {
-    track_file_t *last = NULL;
+    const track_file_t *last = NULL;
    track_t      *cur  = NULL;

    if ((cdi->tracks == NULL) || (cdi->tracks_num == 0))
@@ -273,7 +273,7 @@ cdi_get_audio_tracks_lba(cd_img_t *cdi, int *st_track, int *end, uint32_t *lead_
 int
 cdi_get_audio_track_pre(cd_img_t *cdi, int track)
 {
-    track_t *trk = &cdi->tracks[track - 1];
+    const track_t *trk = &cdi->tracks[track - 1];

    if ((track < 1) || (track > cdi->tracks_num))
        return 0;
@@ -285,7 +285,7 @@ cdi_get_audio_track_pre(cd_img_t *cdi, int track)
 int
 cdi_get_audio_track_info(cd_img_t *cdi, UNUSED(int end), int track, int *track_num, TMSF *start, uint8_t *attr)
 {
-    track_t *trk = &cdi->tracks[track - 1];
+    const track_t *trk = &cdi->tracks[track - 1];
    int      pos = trk->start + 150;

    if ((track < 1) || (track > cdi->tracks_num))
@@ -304,7 +304,7 @@ cdi_get_audio_track_info(cd_img_t *cdi, UNUSED(int end), int track, int *track_n
 int
 cdi_get_audio_track_info_lba(cd_img_t *cdi, UNUSED(int end), int track, int *track_num, uint32_t *start, uint8_t *attr)
 {
-    track_t *trk = &cdi->tracks[track - 1];
+    const track_t *trk = &cdi->tracks[track - 1];

    if ((track < 1) || (track > cdi->tracks_num))
        return 0;
@@ -320,8 +320,8 @@ cdi_get_audio_track_info_lba(cd_img_t *cdi, UNUSED(int end), int track, int *tra
 int
 cdi_get_track(cd_img_t *cdi, uint32_t sector)
 {
-    track_t *cur;
-    track_t *next;
+    const track_t *cur;
+    const track_t *next;

    /* There must be at least two tracks - data and lead out. */
    if (cdi->tracks_num < 2)
@@ -343,8 +343,8 @@ cdi_get_track(cd_img_t *cdi, uint32_t sector)
 int
 cdi_get_audio_sub(cd_img_t *cdi, uint32_t sector, uint8_t *attr, uint8_t *track, uint8_t *index, TMSF *rel_pos, TMSF *abs_pos)
 {
-    int      cur_track = cdi_get_track(cdi, sector);
-    track_t *trk;
+    int            cur_track = cdi_get_track(cdi, sector);
+    const track_t *trk;

    if (cur_track < 1)
        return 0;
@@ -483,8 +483,8 @@ cdi_read_sector_sub(cd_img_t *cdi, uint8_t *buffer, uint32_t sector)
 int
 cdi_get_sector_size(cd_img_t *cdi, uint32_t sector)
 {
-    int      track = cdi_get_track(cdi, sector) - 1;
-    track_t *trk;
+    int            track = cdi_get_track(cdi, sector) - 1;
+    const track_t *trk;

    if (track < 0)
        return 0;
@@ -496,8 +496,8 @@ cdi_get_sector_size(cd_img_t *cdi, uint32_t sector)
 int
 cdi_is_mode2(cd_img_t *cdi, uint32_t sector)
 {
-    int      track = cdi_get_track(cdi, sector) - 1;
-    track_t *trk;
+    int            track = cdi_get_track(cdi, sector) - 1;
+    const track_t *trk;

    if (track < 0)
        return 0;
@@ -510,8 +510,8 @@ cdi_is_mode2(cd_img_t *cdi, uint32_t sector)
 int
 cdi_get_mode2_form(cd_img_t *cdi, uint32_t sector)
 {
-    int      track = cdi_get_track(cdi, sector) - 1;
-    track_t *trk;
+    int            track = cdi_get_track(cdi, sector) - 1;
+    const track_t *trk;

    if (track < 0)
        return 0;
@@ -652,7 +652,9 @@ cdi_cue_get_buffer(char *str, char **line, int up)
                    done = 1;
                    break;
                }
-                /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                [[fallthrough]];
+#endif

            default:
                if (up && islower((int) *s))
@@ -787,7 +789,7 @@ cdi_add_track(cd_img_t *cdi, track_t *cur, uint64_t *shift, uint64_t prestart, u
        *total_pregap += cur_pregap;
        cur->start += *total_pregap;
    } else {
-        temp         = prev->file->get_length(prev->file) - ((uint64_t) prev->skip);
+        temp         = prev->file->get_length(prev->file) - (prev->skip);
        prev->length = temp / ((uint64_t) prev->sector_size);
        if ((temp % prev->sector_size) != 0)
            prev->length++;
--- a/src/cdrom/cdrom_image_viso.c
+++ b/src/cdrom/cdrom_image_viso.c
@@ -370,7 +370,7 @@ viso_fill_fn_rr(uint8_t *data, const viso_entry_t *entry, size_t max_len)

        /* Relocate extension if the original name exceeds the maximum length. */
        if (!S_ISDIR(entry->stats.st_mode)) { /* do this on files only */
-            char *ext = strrchr(entry->basename, '.');
+            const char *ext = strrchr(entry->basename, '.');
            if (ext > entry->basename) {
                len = strlen(ext);
                if (len >= max_len)
@@ -401,7 +401,7 @@ viso_fill_fn_joliet(uint8_t *data, const viso_entry_t *entry, size_t max_len) /*

        /* Relocate extension if the original name exceeds the maximum length. */
        if (!S_ISDIR(entry->stats.st_mode)) { /* do this on files only */
-            wchar_t *ext = wcsrchr(utf8dec, L'.');
+            const wchar_t *ext = wcsrchr(utf8dec, L'.');
            if (ext > utf8dec) {
                len = wcslen(ext);
                if (len > max_len)
@@ -725,8 +725,9 @@ viso_read(void *p, uint8_t *buffer, uint64_t seek, size_t count)
 uint64_t
 viso_get_length(void *p)
 {
-    track_file_t *tf   = (track_file_t *) p;
-    viso_t       *viso = (viso_t *) tf->priv;
+    track_file_t       *tf   = (track_file_t *) p;
+    const viso_t       *viso = (viso_t *) tf->priv;
+
    return ((uint64_t) viso->all_sectors) * viso->sector_size;
 }

@@ -799,18 +800,18 @@ viso_init(const char *dirname, int *error)

    /* Set up directory traversal. */
    cdrom_image_viso_log("VISO: Traversing directories:\n");
-    viso_entry_t  *entry;
-    viso_entry_t  *last_entry;
-    viso_entry_t  *dir;
-    viso_entry_t  *last_dir;
-    viso_entry_t  *eltorito_dir = NULL;
-    viso_entry_t  *eltorito_entry = NULL;
-    struct dirent *readdir_entry;
-    int            len;
-    int            eltorito_others_present = 0;
-    size_t         dir_path_len;
-    uint64_t       eltorito_offset = 0;
-    uint8_t        eltorito_type   = 0;
+    viso_entry_t        *entry;
+    viso_entry_t        *last_entry;
+    viso_entry_t        *dir;
+    viso_entry_t        *last_dir;
+    const viso_entry_t  *eltorito_dir = NULL;
+    const viso_entry_t  *eltorito_entry = NULL;
+    struct dirent       *readdir_entry;
+    int                  len;
+    int                  eltorito_others_present = 0;
+    size_t               dir_path_len;
+    uint64_t             eltorito_offset = 0;
+    uint8_t              eltorito_type   = 0;

    /* Fill root directory entry. */
    dir_path_len = strlen(dirname);
--- a/src/cdrom/cdrom_mitsumi.c
+++ b/src/cdrom/cdrom_mitsumi.c
@@ -324,6 +324,9 @@ mitsumi_cdrom_out(uint16_t port, uint8_t val, void *priv)
                                break;
                            case 5:
                                dev->readmsf = 0;
+#ifdef FALLTHROUGH_ANNOTATION
+                                [[fallthrough]];
+#endif
                            case 4:
                            case 3:
                                dev->readmsf |= CD_DCB(val) << ((dev->cmdrd_count - 3) << 3);
--- a/src/chipset/82c100.c
+++ b/src/chipset/82c100.c
@@ -109,7 +109,7 @@ ct_82c100_ems_out(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 ct_82c100_ems_in(uint16_t port, void *priv)
 {
-    ct_82c100_t *dev = (ct_82c100_t *) priv;
+    const ct_82c100_t *dev = (ct_82c100_t *) priv;
    uint8_t      ret = 0xff;

    ret = dev->ems_page_regs[port >> 14];
@@ -278,15 +278,15 @@ ct_82c100_in(uint16_t port, void *priv)
 static uint8_t
 mem_read_emsb(uint32_t addr, void *priv)
 {
-    ems_page_t *page = (ems_page_t *) priv;
-    uint8_t     ret  = 0xff;
+    const ems_page_t *page = (ems_page_t *) priv;
+    uint8_t           ret  = 0xff;
 #ifdef ENABLE_CT_82C100_LOG
    uint32_t old_addr = addr;
 #endif

    addr = addr - page->virt + page->phys;

-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ret = ram[addr];

    ct_82c100_log("mem_read_emsb(%08X = %08X): %02X\n", old_addr, addr, ret);
@@ -297,7 +297,7 @@ mem_read_emsb(uint32_t addr, void *priv)
 static uint16_t
 mem_read_emsw(uint32_t addr, void *priv)
 {
-    ems_page_t *page = (ems_page_t *) priv;
+    const ems_page_t *page = (ems_page_t *) priv;
    uint16_t    ret  = 0xffff;
 #ifdef ENABLE_CT_82C100_LOG
    uint32_t old_addr = addr;
@@ -305,7 +305,7 @@ mem_read_emsw(uint32_t addr, void *priv)

    addr = addr - page->virt + page->phys;

-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ret = *(uint16_t *) &ram[addr];

    ct_82c100_log("mem_read_emsw(%08X = %08X): %04X\n", old_addr, addr, ret);
@@ -316,14 +316,14 @@ mem_read_emsw(uint32_t addr, void *priv)
 static void
 mem_write_emsb(uint32_t addr, uint8_t val, void *priv)
 {
-    ems_page_t *page = (ems_page_t *) priv;
+    const ems_page_t *page = (ems_page_t *) priv;
 #ifdef ENABLE_CT_82C100_LOG
    uint32_t old_addr = addr;
 #endif

    addr = addr - page->virt + page->phys;

-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ram[addr] = val;

    ct_82c100_log("mem_write_emsb(%08X = %08X, %02X)\n", old_addr, addr, val);
@@ -332,14 +332,14 @@ mem_write_emsb(uint32_t addr, uint8_t val, void *priv)
 static void
 mem_write_emsw(uint32_t addr, uint16_t val, void *priv)
 {
-    ems_page_t *page = (ems_page_t *) priv;
+    const ems_page_t *page = (ems_page_t *) priv;
 #ifdef ENABLE_CT_82C100_LOG
    uint32_t old_addr = addr;
 #endif

    addr = addr - page->virt + page->phys;

-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        *(uint16_t *) &ram[addr] = val;

    ct_82c100_log("mem_write_emsw(%08X = %08X, %04X)\n", old_addr, addr, val);
--- a/src/chipset/acc2168.c
+++ b/src/chipset/acc2168.c
@@ -168,7 +168,7 @@ acc2168_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 acc2168_read(uint16_t addr, void *priv)
 {
-    acc2168_t *dev = (acc2168_t *) priv;
+    const acc2168_t *dev = (acc2168_t *) priv;

    return (addr == 0xf3) ? dev->regs[dev->reg_idx] : dev->reg_idx;
 }
--- a/src/chipset/ali1429.c
+++ b/src/chipset/ali1429.c
@@ -280,8 +280,8 @@ ali1429_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 ali1429_read(uint16_t addr, void *priv)
 {
-    ali1429_t *dev = (ali1429_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1429_t *dev = (ali1429_t *) priv;
+    uint8_t          ret = 0xff;

    if ((addr == 0x23) && (dev->index >= 0x10) && (dev->index <= 0x4a))
        ret = dev->regs[dev->index];
--- a/src/chipset/ali1435.c
+++ b/src/chipset/ali1435.c
@@ -166,8 +166,8 @@ ali1435_pci_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 ali1435_pci_read(int func, int addr, void *priv)
 {
-    ali1435_t *dev = (ali1435_t *) priv;
-    uint8_t    ret;
+    const ali1435_t *dev = (ali1435_t *) priv;
+    uint8_t          ret;

    ret = 0xff;

@@ -233,8 +233,8 @@ ali1435_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 ali1435_read(uint16_t addr, void *priv)
 {
-    ali1435_t *dev = (ali1435_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1435_t *dev = (ali1435_t *) priv;
+    uint8_t          ret = 0xff;

    if ((addr == 0x23) && (dev->index < 0x10))
        ret = dev->regs[dev->index];
--- a/src/chipset/ali1489.c
+++ b/src/chipset/ali1489.c
@@ -213,7 +213,7 @@ ali1489_write(uint16_t addr, uint8_t val, void *priv)
    ali1489_t    *dev = (ali1489_t *) priv;
    uint8_t       old;
    uint8_t       irq;
-    const uint8_t irq_array[16] = { 0, 3, 4, 7, 0, 0, 0, 0, 9, 10, 5, 6, 11, 12, 14, 15 };
+    const uint8_t irq_array[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 0, 11, 0, 12, 0, 14, 0, 15 };

    switch (addr) {
        case 0x22:
@@ -408,8 +408,8 @@ ali1489_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 ali1489_read(uint16_t addr, void *priv)
 {
-    uint8_t    ret = 0xff;
-    ali1489_t *dev = (ali1489_t *) priv;
+    uint8_t          ret = 0xff;
+    const ali1489_t *dev = (ali1489_t *) priv;

    switch (addr) {
        case 0x23:
@@ -456,8 +456,8 @@ ali1489_pci_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 ali1489_pci_read(UNUSED(int func), int addr, void *priv)
 {
-    ali1489_t *dev = (ali1489_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1489_t *dev = (ali1489_t *) priv;
+    uint8_t          ret = 0xff;

    ret = dev->pci_conf[addr];
    ali1489_log("M1489-PCI: dev->pci_conf[%02x] (%02x)\n", addr, ret);
@@ -560,8 +560,8 @@ ali1489_ide_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 ali1489_ide_read(uint16_t addr, void *priv)
 {
-    ali1489_t *dev = (ali1489_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1489_t *dev = (ali1489_t *) priv;
+    uint8_t          ret = 0xff;

    switch (addr) {
        case 0xf4:
--- a/src/chipset/ali1531.c
+++ b/src/chipset/ali1531.c
@@ -303,8 +303,8 @@ ali1531_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 ali1531_read(UNUSED(int func), int addr, void *priv)
 {
-    ali1531_t *dev = (ali1531_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1531_t *dev = (ali1531_t *) priv;
+    uint8_t          ret = 0xff;

    ret = dev->pci_conf[addr];

--- a/src/chipset/ali1541.c
+++ b/src/chipset/ali1541.c
@@ -560,8 +560,8 @@ ali1541_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 ali1541_read(UNUSED(int func), int addr, void *priv)
 {
-    ali1541_t *dev = (ali1541_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1541_t *dev = (ali1541_t *) priv;
+    uint8_t          ret = 0xff;

    ret = dev->pci_conf[addr];

--- a/src/chipset/ali1543.c
+++ b/src/chipset/ali1543.c
@@ -895,7 +895,7 @@ ali5229_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 ali5229_read(int func, int addr, void *priv)
 {
-    ali1543_t *dev = (ali1543_t *) priv;
+    const ali1543_t *dev = (ali1543_t *) priv;
    uint8_t    ret = 0xff;

    if (dev->ide_dev_enable && (func == 0)) {
@@ -983,7 +983,7 @@ ali5237_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 ali5237_read(int func, int addr, void *priv)
 {
-    ali1543_t *dev = (ali1543_t *) priv;
+    const ali1543_t *dev = (ali1543_t *) priv;
    uint8_t    ret = 0xff;

    if (dev->usb_dev_enable && (func == 0))
@@ -1474,7 +1474,7 @@ ali7101_read(int func, int addr, void *priv)
 static void
 ali5237_usb_update_interrupt(usb_t* usb, void *priv)
 {
-    ali1543_t *dev = (ali1543_t *) priv;
+    const ali1543_t *dev = (ali1543_t *) priv;

    if (usb->irq_level)
        pci_set_mirq(4, !!(dev->pci_conf[0x74] & 0x10));
--- a/src/chipset/ali1621.c
+++ b/src/chipset/ali1621.c
@@ -28,6 +28,7 @@
 #include <86box/io.h>
 #include <86box/mem.h>
 #include <86box/pci.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 #include <86box/smram.h>
 #include <86box/spd.h>
@@ -108,7 +109,9 @@ ali1621_smram_recalc(uint8_t val, ali1621_t *dev)
            switch (val & 0x30) {
                case 0x10: /* Open. */
                    access_normal = ACCESS_SMRAM_RX;
-                    /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif
                case 0x30: /* Protect. */
                    access_smm |= ACCESS_SMRAM_R;
                    break;
@@ -121,7 +124,9 @@ ali1621_smram_recalc(uint8_t val, ali1621_t *dev)
            switch (val & 0x30) {
                case 0x10: /* Open. */
                    access_normal |= ACCESS_SMRAM_W;
-                    /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif
                case 0x30: /* Protect. */
                    access_smm |= ACCESS_SMRAM_W;
                    break;
@@ -579,8 +584,8 @@ ali1621_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 ali1621_read(UNUSED(int func), int addr, void *priv)
 {
-    ali1621_t *dev = (ali1621_t *) priv;
-    uint8_t    ret = 0xff;
+    const ali1621_t *dev = (ali1621_t *) priv;
+    uint8_t          ret = 0xff;

    ret = dev->pci_conf[addr];

--- a/src/chipset/ali6117.c
+++ b/src/chipset/ali6117.c
@@ -33,6 +33,7 @@
 #include <86box/hdc.h>
 #include <86box/hdc_ide.h>
 #include <86box/chipset.h>
+#include <86box/plat_fallthrough.h>

 typedef struct ali6117_t {
    uint32_t local;
@@ -233,7 +234,9 @@ ali6117_reg_write(uint16_t addr, uint8_t val, void *priv)

                case 0x12:
                    val &= 0xf7;
-                    /* FALL-THROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                case 0x14:
                case 0x15:
@@ -388,7 +391,7 @@ ali6117_reg_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 ali6117_reg_read(uint16_t addr, void *priv)
 {
-    ali6117_t *dev = (ali6117_t *) priv;
+    const ali6117_t *dev = (ali6117_t *) priv;
    uint8_t    ret;

    if (addr == 0x22)
--- a/src/chipset/cs4031.c
+++ b/src/chipset/cs4031.c
@@ -148,7 +148,7 @@ cs4031_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 cs4031_read(uint16_t addr, void *priv)
 {
-    cs4031_t *dev = (cs4031_t *) priv;
+    const cs4031_t *dev = (cs4031_t *) priv;

    return (addr == 0x23) ? dev->regs[dev->index] : 0xff;
 }
--- a/src/chipset/cs8230.c
+++ b/src/chipset/cs8230.c
@@ -81,8 +81,8 @@ rethink_shadow_mappings(cs8230_t *cs8230)
 static uint8_t
 cs8230_read(uint16_t port, void *priv)
 {
-    cs8230_t *cs8230 = (cs8230_t *) priv;
-    uint8_t   ret    = 0xff;
+    const cs8230_t *cs8230 = (cs8230_t *) priv;
+    uint8_t         ret    = 0xff;

    if (port & 1) {
        switch (cs8230->idx) {
--- a/src/chipset/et6000.c
+++ b/src/chipset/et6000.c
@@ -121,7 +121,7 @@ et6000_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 et6000_read(uint16_t addr, void *priv)
 {
-    et6000_t *dev = (et6000_t *) priv;
+    const et6000_t *dev = (et6000_t *) priv;

    return ((addr == 0x23) && (INDEX >= 0) && (INDEX <= 5)) ? dev->regs[INDEX] : 0xff;
 }
--- a/src/chipset/gc100.c
+++ b/src/chipset/gc100.c
@@ -145,9 +145,9 @@ gc100_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 gc100_read(uint16_t port, void *priv)
 {
-    gc100_t *dev  = (gc100_t *) priv;
-    uint8_t  ret  = 0xff;
-    uint16_t addr = port & 0xf;
+    const gc100_t *dev  = (gc100_t *) priv;
+    uint8_t        ret  = 0xff;
+    uint16_t       addr = port & 0xf;

    ret = dev->reg[addr];

--- a/src/chipset/headland.c
+++ b/src/chipset/headland.c
@@ -165,7 +165,7 @@ get_addr(headland_t *dev, uint32_t addr, headland_mr_t *mr)
 static void
 hl_ems_disable(headland_t *dev, uint8_t mar, uint32_t base_addr, uint8_t indx)
 {
-    if (base_addr < ((uint32_t) mem_size << 10))
+    if (base_addr < (mem_size << 10))
        mem_mapping_set_exec(&dev->ems_mapping[mar & 0x3f], ram + base_addr);
    else
        mem_mapping_set_exec(&dev->ems_mapping[mar & 0x3f], NULL);
@@ -197,7 +197,7 @@ hl_ems_update(headland_t *dev, uint8_t mar)
        dev->ems_mr[mar & 0x3f].virt_base = virt_addr;
        if (indx < 24)
            mem_mapping_disable(&dev->upper_mapping[indx]);
-        if (virt_addr < ((uint32_t) mem_size << 10))
+        if (virt_addr < (mem_size << 10))
            mem_mapping_set_exec(&dev->ems_mapping[mar & 0x3f], ram + virt_addr);
        else
            mem_mapping_set_exec(&dev->ems_mapping[mar & 0x3f], NULL);
@@ -244,7 +244,7 @@ memmap_state_update(headland_t *dev)

    for (uint8_t i = 0; i < 24; i++) {
        addr = get_addr(dev, 0x40000 + (i << 14), NULL);
-        mem_mapping_set_exec(&dev->upper_mapping[i], addr < ((uint32_t) mem_size << 10) ? ram + addr : NULL);
+        mem_mapping_set_exec(&dev->upper_mapping[i], addr < (mem_size << 10) ? ram + addr : NULL);
    }

    memmap_state_default(dev, ht_romcs);
@@ -513,7 +513,7 @@ mem_read_b(uint32_t addr, void *priv)
    uint8_t        ret = 0xff;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ret = ram[addr];

    return ret;
@@ -527,7 +527,7 @@ mem_read_w(uint32_t addr, void *priv)
    uint16_t       ret = 0xffff;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ret = *(uint16_t *) &ram[addr];

    return ret;
@@ -541,7 +541,7 @@ mem_read_l(uint32_t addr, void *priv)
    uint32_t       ret = 0xffffffff;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ret = *(uint32_t *) &ram[addr];

    return ret;
@@ -554,7 +554,7 @@ mem_write_b(uint32_t addr, uint8_t val, void *priv)
    headland_t    *dev = mr->headland;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        ram[addr] = val;
 }

@@ -565,7 +565,7 @@ mem_write_w(uint32_t addr, uint16_t val, void *priv)
    headland_t    *dev = mr->headland;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        *(uint16_t *) &ram[addr] = val;
 }

@@ -576,7 +576,7 @@ mem_write_l(uint32_t addr, uint32_t val, void *priv)
    headland_t    *dev = mr->headland;

    addr = get_addr(dev, addr, mr);
-    if (addr < ((uint32_t) mem_size << 10))
+    if (addr < (mem_size << 10))
        *(uint32_t *) &ram[addr] = val;
 }

--- a/src/chipset/ims8848.c
+++ b/src/chipset/ims8848.c
@@ -327,8 +327,8 @@ ims8849_pci_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 ims8849_pci_read(int func, int addr, void *priv)
 {
-    ims8848_t *dev = (ims8848_t *) priv;
-    uint8_t    ret = 0xff;
+    const ims8848_t *dev = (ims8848_t *) priv;
+    uint8_t          ret = 0xff;

    if (func == 0)
        ret = dev->pci_conf[addr];
--- a/src/chipset/intel_420ex.c
+++ b/src/chipset/intel_420ex.c
@@ -118,7 +118,7 @@ i420ex_smram_handler_phase0(void)
 static void
 i420ex_smram_handler_phase1(i420ex_t *dev)
 {
-    uint8_t *regs = (uint8_t *) dev->regs;
+    const uint8_t *regs = (uint8_t *) dev->regs;

    uint32_t host_base = 0x000a0000;
    uint32_t ram_base  = 0x000a0000;
@@ -165,15 +165,14 @@ i420ex_smram_handler_phase1(i420ex_t *dev)
 static void
 i420ex_drb_recalc(i420ex_t *dev)
 {
-    int i;
    uint32_t boundary;

-    for (i = 4; i >= 0; i--)
+    for (int8_t i = 4; i >= 0; i--)
        row_disable(i);

-    for (i = 0; i <= 4; i++) {
-	boundary = ((uint32_t) dev->regs[0x60 + i]) & 0xff;
-	row_set_boundary(i, boundary);
+    for (uint8_t i = 0; i <= 4; i++) {
+        boundary = ((uint32_t) dev->regs[0x60 + i]) & 0xff;
+        row_set_boundary(i, boundary);
    }

    flushmmucache();
@@ -398,8 +397,8 @@ i420ex_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 i420ex_read(int func, int addr, void *priv)
 {
-    i420ex_t *dev = (i420ex_t *) priv;
-    uint8_t   ret;
+    const i420ex_t *dev = (i420ex_t *) priv;
+    uint8_t         ret;

    ret = 0xff;

--- a/src/chipset/intel_4x0.c
+++ b/src/chipset/intel_4x0.c
@@ -118,10 +118,10 @@ static void
 i4x0_smram_handler_phase1(i4x0_t *dev)
 {

-    uint8_t *regs    = (uint8_t *) dev->regs;
-    uint32_t tom     = (mem_size << 10);
-    uint8_t *reg     = (dev->type >= INTEL_430LX) ? &(regs[0x72]) : &(regs[0x57]);
-    uint8_t *ext_reg = (dev->type >= INTEL_440BX) ? &(regs[0x73]) : &(regs[0x71]);
+    const uint8_t *regs    = (uint8_t *) dev->regs;
+    uint32_t       tom     = (mem_size << 10);
+    const uint8_t *reg     = (dev->type >= INTEL_430LX) ? &(regs[0x72]) : &(regs[0x57]);
+    const uint8_t *ext_reg = (dev->type >= INTEL_440BX) ? &(regs[0x73]) : &(regs[0x71]);

    uint32_t s;
    uint32_t base[2] = { 0x000a0000, 0x00000000 };
@@ -228,7 +228,7 @@ i4x0_mask_bar(uint8_t *regs, void *agpgart)
 static uint8_t
 pm2_cntrl_read(UNUSED(uint16_t addr), void *priv)
 {
-    i4x0_t *dev = (i4x0_t *) priv;
+    const i4x0_t *dev = (i4x0_t *) priv;

    return dev->pm2_cntrl & 0x01;
 }
@@ -1068,6 +1068,8 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
                    case INTEL_440ZX:
                    case INTEL_440GX:
                        regs[addr] = val;
+                        break;
+
                    default:
                        break;
                }
@@ -1077,6 +1079,8 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
                    case INTEL_440BX:
                    case INTEL_440ZX:
                        regs[0x77] = val & 0x03;
+                        break;
+
                    default:
                        break;
                }
@@ -1505,9 +1509,9 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 i4x0_read(int func, int addr, void *priv)
 {
-    i4x0_t  *dev  = (i4x0_t *) priv;
-    uint8_t  ret  = 0xff;
-    uint8_t *regs = (uint8_t *) dev->regs;
+    i4x0_t        *dev  = (i4x0_t *) priv;
+    uint8_t        ret  = 0xff;
+    const uint8_t *regs = (uint8_t *) dev->regs;

    if (func == 0) {
        ret = regs[addr];
--- a/src/chipset/intel_82335.c
+++ b/src/chipset/intel_82335.c
@@ -153,7 +153,7 @@ intel_82335_write(uint16_t addr, uint16_t val, void *priv)
 static uint16_t
 intel_82335_read(uint16_t addr, void *priv)
 {
-    intel_82335_t *dev = (intel_82335_t *) priv;
+    const intel_82335_t *dev = (intel_82335_t *) priv;

    intel_82335_log("Register %02x: Read %04x\n", addr, dev->regs[addr]);

--- a/src/chipset/intel_i450kx.c
+++ b/src/chipset/intel_i450kx.c
@@ -90,9 +90,9 @@ i450kx_map(i450kx_t *dev, int bus, uint32_t addr, uint32_t size, int state)
 static void
 i450kx_smram_recalc(i450kx_t *dev, int bus)
 {
-    uint8_t *regs = bus ? dev->pb_pci_conf : dev->mc_pci_conf;
-    uint32_t addr;
-    uint32_t size;
+    const uint8_t *regs = bus ? dev->pb_pci_conf : dev->mc_pci_conf;
+    uint32_t       addr;
+    uint32_t       size;

    smram_disable(dev->smram[bus]);

@@ -112,7 +112,7 @@ i450kx_smram_recalc(i450kx_t *dev, int bus)
 static void
 i450kx_vid_buf_recalc(i450kx_t *dev, int bus)
 {
-    uint8_t *regs = bus ? dev->pb_pci_conf : dev->mc_pci_conf;
+    const uint8_t *regs = bus ? dev->pb_pci_conf : dev->mc_pci_conf;

 #if 0
    // int state = (regs[0x58] & 0x02) ? (MEM_READ_EXTANY | MEM_WRITE_EXTANY) : (MEM_READ_DISABLED | MEM_WRITE_DISABLED);
@@ -374,7 +374,7 @@ pb_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 pb_read(int func, int addr, void *priv)
 {
-    i450kx_t *dev = (i450kx_t *) priv;
+    const i450kx_t *dev = (i450kx_t *) priv;
    uint8_t   ret = 0xff;

    if (func == 0)
@@ -601,7 +601,7 @@ mc_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 mc_read(int func, int addr, void *priv)
 {
-    i450kx_t *dev = (i450kx_t *) priv;
+    const i450kx_t *dev = (i450kx_t *) priv;
    uint8_t   ret = 0xff;

    if (func == 0)
--- a/src/chipset/intel_piix.c
+++ b/src/chipset/intel_piix.c
@@ -289,7 +289,7 @@ piix_trap_io(UNUSED(int size), UNUSED(uint16_t addr), UNUSED(uint8_t write), UNU
 static void
 piix_trap_io_ide(int size, uint16_t addr, uint8_t write, uint8_t val, void *priv)
 {
-    piix_io_trap_t *trap = (piix_io_trap_t *) priv;
+    const piix_io_trap_t *trap = (piix_io_trap_t *) priv;

    /* IDE traps are per drive, not per channel. */
    if (ide_drives[trap->dev_id]->selected)
@@ -327,10 +327,10 @@ piix_trap_update_devctl(piix_t *dev, uint8_t trap_id, uint8_t dev_id,
 static void
 piix_trap_update(void *priv)
 {
-    piix_t  *dev     = (piix_t *) priv;
-    uint8_t  trap_id = 0;
-    uint8_t *fregs   = dev->regs[3];
-    uint16_t temp;
+    piix_t        *dev     = (piix_t *) priv;
+    uint8_t        trap_id = 0;
+    const uint8_t *fregs   = dev->regs[3];
+    uint16_t       temp;

    piix_trap_update_devctl(dev, trap_id++, 0, 0x00000002, 1, 0x1f0, 8);
    piix_trap_update_devctl(dev, trap_id++, 0, 0x00000002, 1, 0x3f6, 1);
@@ -1166,9 +1166,9 @@ piix_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 piix_read(int func, int addr, void *priv)
 {
-    piix_t  *dev = (piix_t *) priv;
-    uint8_t  ret = 0xff;
-    uint8_t *fregs;
+    piix_t        *dev = (piix_t *) priv;
+    uint8_t        ret = 0xff;
+    const uint8_t *fregs;

    if ((dev->type == 3) && (func == 2) && (dev->max_func == 1) && (addr >= 0x40))
        ret = 0x00;
@@ -1202,8 +1202,8 @@ board_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 board_read(uint16_t port, void *priv)
 {
-    piix_t *dev = (piix_t *) priv;
-    uint8_t ret = 0x64;
+    const piix_t *dev = (piix_t *) priv;
+    uint8_t       ret = 0x64;

    if (port == 0x0078)
        ret = dev->board_config[0];
@@ -1446,7 +1446,7 @@ piix_fast_off_count(void *priv)
 static void
 piix_usb_update_interrupt(usb_t* usb, void *priv)
 {
-    piix_t *dev = (piix_t *) priv;
+    const piix_t *dev = (piix_t *) priv;

    if (usb->irq_level)
        pci_set_irq(dev->pci_slot, PCI_INTD);
@@ -1457,7 +1457,7 @@ piix_usb_update_interrupt(usb_t* usb, void *priv)
 static void
 piix_reset(void *priv)
 {
-    piix_t *dev = (piix_t *) priv;
+    const piix_t *dev = (piix_t *) priv;

    if (dev->type > 3) {
        piix_write(3, 0x04, 0x00, priv);
--- a/src/chipset/intel_sio.c
+++ b/src/chipset/intel_sio.c
@@ -324,8 +324,8 @@ sio_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 sio_read(int func, int addr, void *priv)
 {
-    sio_t  *dev = (sio_t *) priv;
-    uint8_t ret;
+    const sio_t  *dev = (sio_t *) priv;
+    uint8_t       ret;

    ret = 0xff;

@@ -452,7 +452,7 @@ sio_fast_off_count(void *priv)
 static void
 sio_reset(void *priv)
 {
-    sio_t *dev = (sio_t *) priv;
+    const sio_t *dev = (sio_t *) priv;

    /* Disable the PIC mouse latch. */
    sio_write(0, 0x4d, 0x40, priv);
--- a/src/chipset/neat.c
+++ b/src/chipset/neat.c
@@ -349,9 +349,9 @@ ems_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 ems_read(uint16_t port, void *priv)
 {
-    neat_t *dev = (neat_t *) priv;
-    uint8_t ret = 0xff;
-    int     vpage;
+    const neat_t *dev = (neat_t *) priv;
+    uint8_t       ret = 0xff;
+    int           vpage;

    /* Get the viewport page number. */
    vpage = (port / EMS_PGSIZE);
@@ -637,8 +637,8 @@ neat_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 neat_read(uint16_t port, void *priv)
 {
-    neat_t *dev = (neat_t *) priv;
-    uint8_t ret = 0xff;
+    const neat_t *dev = (neat_t *) priv;
+    uint8_t       ret = 0xff;

    switch (port) {
        case 0x22:
--- a/src/chipset/opti283.c
+++ b/src/chipset/opti283.c
@@ -29,6 +29,7 @@
 #include <86box/io.h>
 #include <86box/device.h>
 #include <86box/mem.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 #include <86box/chipset.h>

@@ -66,7 +67,7 @@ typedef struct opti283_t {
 static uint8_t
 opti283_read_remapped_ram(uint32_t addr, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    return mem_read_ram((addr - dev->virt) + dev->phys, priv);
 }
@@ -74,7 +75,7 @@ opti283_read_remapped_ram(uint32_t addr, void *priv)
 static uint16_t
 opti283_read_remapped_ramw(uint32_t addr, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    return mem_read_ramw((addr - dev->virt) + dev->phys, priv);
 }
@@ -82,7 +83,7 @@ opti283_read_remapped_ramw(uint32_t addr, void *priv)
 static uint32_t
 opti283_read_remapped_raml(uint32_t addr, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    return mem_read_raml((addr - dev->virt) + dev->phys, priv);
 }
@@ -90,7 +91,7 @@ opti283_read_remapped_raml(uint32_t addr, void *priv)
 static void
 opti283_write_remapped_ram(uint32_t addr, uint8_t val, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    mem_write_ram((addr - dev->virt) + dev->phys, val, priv);
 }
@@ -98,7 +99,7 @@ opti283_write_remapped_ram(uint32_t addr, uint8_t val, void *priv)
 static void
 opti283_write_remapped_ramw(uint32_t addr, uint16_t val, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    mem_write_ramw((addr - dev->virt) + dev->phys, val, priv);
 }
@@ -106,7 +107,7 @@ opti283_write_remapped_ramw(uint32_t addr, uint16_t val, void *priv)
 static void
 opti283_write_remapped_raml(uint32_t addr, uint32_t val, void *priv)
 {
-    mem_remapping_t *dev = (mem_remapping_t *) priv;
+    const mem_remapping_t *dev = (mem_remapping_t *) priv;

    mem_write_raml((addr - dev->virt) + dev->phys, val, priv);
 }
@@ -228,7 +229,9 @@ opti283_write(uint16_t addr, uint8_t val, void *priv)

                case 0x14:
                    reset_on_hlt = !!(val & 0x40);
-                    /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif
                case 0x11:
                case 0x12:
                case 0x13:
@@ -249,8 +252,8 @@ opti283_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti283_read(uint16_t addr, void *priv)
 {
-    opti283_t *dev = (opti283_t *) priv;
-    uint8_t    ret = 0xff;
+    const opti283_t *dev = (opti283_t *) priv;
+    uint8_t          ret = 0xff;

    if (addr == 0x24)
        ret = dev->regs[dev->index];
--- a/src/chipset/opti291.c
+++ b/src/chipset/opti291.c
@@ -122,7 +122,7 @@ opti291_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti291_read(uint16_t addr, void *priv)
 {
-    opti291_t *dev = (opti291_t *) priv;
+    const opti291_t *dev = (opti291_t *) priv;

    return (addr == 0x24) ? dev->regs[dev->index] : 0xff;
 }
--- a/src/chipset/opti391.c
+++ b/src/chipset/opti391.c
@@ -178,8 +178,8 @@ opti391_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti391_read(uint16_t addr, void *priv)
 {
-    opti391_t *dev = (opti391_t *) priv;
-    uint8_t    ret = 0xff;
+    const opti391_t *dev = (opti391_t *) priv;
+    uint8_t          ret = 0xff;

    if (addr == 0x24)
        ret = dev->regs[dev->index];
--- a/src/chipset/opti495.c
+++ b/src/chipset/opti495.c
@@ -157,8 +157,8 @@ opti495_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti495_read(uint16_t addr, void *priv)
 {
-    uint8_t    ret = 0xff;
-    opti495_t *dev = (opti495_t *) priv;
+    uint8_t          ret = 0xff;
+    const opti495_t *dev = (opti495_t *) priv;

    switch (addr) {
        case 0x22:
--- a/src/chipset/opti5x7.c
+++ b/src/chipset/opti5x7.c
@@ -156,7 +156,7 @@ opti5x7_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti5x7_read(uint16_t addr, void *priv)
 {
-    opti5x7_t *dev = (opti5x7_t *) priv;
+    const opti5x7_t *dev = (opti5x7_t *) priv;

    return (addr == 0x24) ? dev->regs[dev->idx] : 0xff;
 }
--- a/src/chipset/opti822.c
+++ b/src/chipset/opti822.c
@@ -336,8 +336,8 @@ opti822_pci_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 opti822_pci_read(int func, int addr, void *priv)
 {
-    opti822_t *dev = (opti822_t *) priv;
-    uint8_t    ret;
+    const opti822_t *dev = (opti822_t *) priv;
+    uint8_t          ret;

    ret = 0xff;

--- a/src/chipset/opti895.c
+++ b/src/chipset/opti895.c
@@ -204,8 +204,8 @@ opti895_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 opti895_read(uint16_t addr, void *priv)
 {
-    uint8_t    ret = 0xff;
-    opti895_t *dev = (opti895_t *) priv;
+    uint8_t          ret = 0xff;
+    const opti895_t *dev = (opti895_t *) priv;

    switch (addr) {
        case 0x23:
--- a/src/chipset/scamp.c
+++ b/src/chipset/scamp.c
@@ -152,12 +152,12 @@ static const struct {
 static uint8_t
 ram_mirrored_256k_in_4mi_read(uint32_t addr, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte = addr & 1;
@@ -183,12 +183,12 @@ ram_mirrored_256k_in_4mi_read(uint32_t addr, void *priv)
 static void
 ram_mirrored_256k_in_4mi_write(uint32_t addr, uint8_t val, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte = addr & 1;
@@ -216,12 +216,12 @@ ram_mirrored_256k_in_4mi_write(uint32_t addr, uint8_t val, void *priv)
 static uint8_t
 ram_mirrored_interleaved_read(uint32_t addr, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte = addr & 1;
@@ -247,12 +247,12 @@ ram_mirrored_interleaved_read(uint32_t addr, void *priv)
 static void
 ram_mirrored_interleaved_write(uint32_t addr, uint8_t val, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte = addr & 1;
@@ -278,12 +278,12 @@ ram_mirrored_interleaved_write(uint32_t addr, uint8_t val, void *priv)
 static uint8_t
 ram_mirrored_read(uint32_t addr, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte   = addr & 1;
@@ -297,12 +297,12 @@ ram_mirrored_read(uint32_t addr, void *priv)
 static void
 ram_mirrored_write(uint32_t addr, uint8_t val, void *priv)
 {
-    ram_struct_t *rs   = (ram_struct_t *) priv;
-    scamp_t      *dev  = rs->parent;
-    int           bank = rs->bank;
-    int           byte;
-    int           row;
-    int           column;
+    const ram_struct_t *rs   = (ram_struct_t *) priv;
+    const scamp_t      *dev  = rs->parent;
+    int                 bank = rs->bank;
+    int                 byte;
+    int                 row;
+    int                 column;

    addr -= dev->ram_virt_base[bank];
    byte   = addr & 1;
@@ -574,9 +574,9 @@ recalc_sltptr(scamp_t *dev)
 static uint8_t
 scamp_ems_read(uint32_t addr, void *priv)
 {
-    ems_struct_t *ems     = (ems_struct_t *) priv;
-    scamp_t      *dev     = ems->parent;
-    int           segment = ems->segment;
+    const ems_struct_t *ems     = (ems_struct_t *) priv;
+    const scamp_t      *dev     = ems->parent;
+    int                 segment = ems->segment;

    addr = (addr & 0x3fff) | dev->mappings[segment];
    return ram[addr];
@@ -585,9 +585,9 @@ scamp_ems_read(uint32_t addr, void *priv)
 static void
 scamp_ems_write(uint32_t addr, uint8_t val, void *priv)
 {
-    ems_struct_t *ems     = (ems_struct_t *) priv;
-    scamp_t      *dev     = ems->parent;
-    int           segment = ems->segment;
+    const ems_struct_t *ems     = (ems_struct_t *) priv;
+    const scamp_t      *dev     = ems->parent;
+    int                 segment = ems->segment;

    addr      = (addr & 0x3fff) | dev->mappings[segment];
    ram[addr] = val;
--- a/src/chipset/scat.c
+++ b/src/chipset/scat.c
@@ -1204,9 +1204,9 @@ scat_out(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 scat_in(uint16_t port, void *priv)
 {
-    scat_t *dev = (scat_t *) priv;
-    uint8_t ret = 0xff;
-    uint8_t indx;
+    const scat_t *dev = (scat_t *) priv;
+    uint8_t       ret = 0xff;
+    uint8_t       indx;

    switch (port) {
        case 0x23:
--- a/src/chipset/sis_5511.c
+++ b/src/chipset/sis_5511.c
@@ -348,7 +348,8 @@ sis_5511_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 sis_5511_read(UNUSED(int func), int addr, void *priv)
 {
-    sis_5511_t *dev = (sis_5511_t *) priv;
+    const sis_5511_t *dev = (sis_5511_t *) priv;
+
    sis_5511_log("SiS 5511: dev->pci_conf[%02x] (%02x) POST %02x\n", addr, dev->pci_conf[addr], inb(0x80));
    return dev->pci_conf[addr];
 }
@@ -554,7 +555,7 @@ sis_5513_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 sis_5513_read(int func, int addr, void *priv)
 {
-    sis_5511_t *dev = (sis_5511_t *) priv;
+    const sis_5511_t *dev = (sis_5511_t *) priv;

    sis_5511_log("SiS 5513: dev->pci_conf[%02x][%02x] = %02x POST %02x\n", func, addr, dev->pci_conf_sb[func][addr], inb(0x80));
    if ((func >= 0) && (func <= 1))
@@ -624,7 +625,7 @@ sis_5513_isa_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 sis_5513_isa_read(uint16_t addr, void *priv)
 {
-    sis_5511_t *dev = (sis_5511_t *) priv;
+    const sis_5511_t *dev = (sis_5511_t *) priv;

    if (addr == 0x23) {
        sis_5511_log("SiS 5513-ISA: dev->regs[%02x] (%02x) POST: %02x\n", dev->index + 0x50, dev->regs[dev->index], inb(0x80));
--- a/src/chipset/sis_5571.c
+++ b/src/chipset/sis_5571.c
@@ -340,7 +340,8 @@ memory_pci_bridge_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 memory_pci_bridge_read(UNUSED(int func), int addr, void *priv)
 {
-    sis_5571_t *dev = (sis_5571_t *) priv;
+    const sis_5571_t *dev = (sis_5571_t *) priv;
+
    sis_5571_log("SiS5571: dev->pci_conf[%02x] (%02x)\n", addr, dev->pci_conf[addr]);
    return dev->pci_conf[addr];
 }
@@ -638,6 +639,7 @@ pci_isa_bridge_write(int func, int addr, uint8_t val, void *priv)
                    break;
            }
            sis_5571_log("SiS5571-USB: dev->pci_conf[%02x] = %02x\n", addr, val);
+            break;

        default:
            break;
@@ -647,7 +649,7 @@ pci_isa_bridge_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 pci_isa_bridge_read(int func, int addr, void *priv)
 {
-    sis_5571_t *dev = (sis_5571_t *) priv;
+    const sis_5571_t *dev = (sis_5571_t *) priv;

    switch (func) {
        case 0:
@@ -668,7 +670,7 @@ pci_isa_bridge_read(int func, int addr, void *priv)
 static void
 sis_5571_usb_update_interrupt(usb_t* usb, void* priv)
 {
-    sis_5571_t *dev = (sis_5571_t *) priv;
+    const sis_5571_t *dev = (sis_5571_t *) priv;

    if (dev->pci_conf_sb[0][0x68] & 0x80) {
        /* TODO: Is the normal PCI interrupt inhibited when USB IRQ remapping is enabled? */
--- a/src/chipset/sis_85c496.c
+++ b/src/chipset/sis_85c496.c
@@ -115,8 +115,8 @@ sis_85c497_isa_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 sis_85c497_isa_read(uint16_t port, void *priv)
 {
-    sis_85c496_t *dev = (sis_85c496_t *) priv;
-    uint8_t       ret = 0xff;
+    const sis_85c496_t *dev = (sis_85c496_t *) priv;
+    uint8_t             ret = 0xff;

    if (port == 0x23)
        ret = dev->regs[dev->cur_reg];
@@ -505,8 +505,8 @@ sis_85c49x_pci_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 sis_85c49x_pci_read(UNUSED(int func), int addr, void *priv)
 {
-    sis_85c496_t *dev = (sis_85c496_t *) priv;
-    uint8_t       ret = dev->pci_conf[addr];
+    const sis_85c496_t *dev = (sis_85c496_t *) priv;
+    uint8_t             ret = dev->pci_conf[addr];

    switch (addr) {
        case 0xa0:
@@ -673,7 +673,7 @@ static void
    timer_add(&dev->rmsmiblk_timer, sis_85c496_rmsmiblk_count, dev, 0);

 #ifndef USE_DRB_HACK
-    row_device.local = 7 | (1 << 8) | (0x02 << 16) | (7 << 24);
+    row_device.local = 7 | (1 << 8) | (0x02 << 16) | (8 << 24);
    device_add((const device_t *) &row_device);
 #endif

--- a/src/chipset/sis_85c50x.c
+++ b/src/chipset/sis_85c50x.c
@@ -228,8 +228,8 @@ sis_85c50x_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 sis_85c50x_read(int func, int addr, void *priv)
 {
-    sis_85c50x_t *dev = (sis_85c50x_t *) priv;
-    uint8_t       ret = 0xff;
+    const sis_85c50x_t *dev = (sis_85c50x_t *) priv;
+    uint8_t             ret = 0xff;

    if (func == 0x00)
        ret = dev->pci_conf[addr];
@@ -283,8 +283,8 @@ sis_85c50x_sb_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 sis_85c50x_sb_read(int func, int addr, void *priv)
 {
-    sis_85c50x_t *dev = (sis_85c50x_t *) priv;
-    uint8_t       ret = 0xff;
+    const sis_85c50x_t *dev = (sis_85c50x_t *) priv;
+    uint8_t             ret = 0xff;

    if (func == 0x00)
        ret = dev->pci_conf_sb[addr];
@@ -338,8 +338,8 @@ sis_85c50x_isa_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 sis_85c50x_isa_read(uint16_t addr, void *priv)
 {
-    sis_85c50x_t *dev = (sis_85c50x_t *) priv;
-    uint8_t       ret = 0xff;
+    const sis_85c50x_t *dev = (sis_85c50x_t *) priv;
+    uint8_t             ret = 0xff;

    switch (addr) {
        case 0x22:
--- a/src/chipset/stpc.c
+++ b/src/chipset/stpc.c
@@ -166,8 +166,8 @@ stpc_host_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 stpc_host_read(uint16_t addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (addr == dev->host_base)
        ret = dev->host_offset;
@@ -196,8 +196,8 @@ stpc_localbus_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 stpc_localbus_read(uint16_t addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (addr == dev->localbus_base)
        ret = dev->localbus_offset;
@@ -260,8 +260,8 @@ stpc_nb_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 stpc_nb_read(int func, int addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (func > 0)
        ret = 0xff;
@@ -445,8 +445,8 @@ stpc_ide_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 stpc_ide_read(int func, int addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (func > 0)
        ret = 0xff;
@@ -507,8 +507,8 @@ stpc_isab_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 stpc_isab_read(int func, int addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if ((func == 1) && (dev->local != STPC_ATLAS))
        ret = stpc_ide_read(0, addr, priv);
@@ -571,8 +571,8 @@ stpc_usb_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 stpc_usb_read(int func, int addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (func > 0)
        ret = 0xff;
@@ -614,7 +614,8 @@ stpc_remap_localbus(stpc_t *dev, uint16_t localbus_base)
 static uint8_t
 stpc_serial_handlers(uint8_t val)
 {
-    stpc_serial_t *dev = device_get_priv(&stpc_serial_device);
+    const stpc_serial_t *dev = device_get_priv(&stpc_serial_device);
+
    if (!dev) {
        stpc_log("STPC: Not remapping UARTs, disabled by strap (raw %02X)\n", val);
        return 0;
@@ -744,8 +745,8 @@ stpc_reg_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 stpc_reg_read(uint16_t addr, void *priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
-    uint8_t ret;
+    const stpc_t *dev = (stpc_t *) priv;
+    uint8_t       ret;

    if (addr == 0x22)
        ret = dev->reg_offset;
@@ -895,7 +896,7 @@ stpc_setup(stpc_t *dev)
 static void
 stpc_usb_update_interrupt(usb_t* usb, void* priv)
 {
-    stpc_t *dev = (stpc_t *) priv;
+    const stpc_t *dev = (stpc_t *) priv;

    if (usb->irq_level)
        pci_set_irq(dev->usb_slot, PCI_INTA);
--- a/src/chipset/umc_8886.c
+++ b/src/chipset/umc_8886.c
@@ -202,7 +202,7 @@ umc_8886_write(int func, int addr, uint8_t val, void *priv)
                    case 0x56:
                        dev->pci_conf_sb[func][addr] = val;

-                        switch (val & 2) {
+                        switch (val & 3) {
                            case 0:
                                cpu_set_isa_pci_div(3);
                                break;
@@ -289,8 +289,8 @@ umc_8886_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 umc_8886_read(int func, int addr, void *priv)
 {
-    umc_8886_t *dev = (umc_8886_t *) priv;
-    uint8_t     ret = 0xff;
+    const umc_8886_t *dev = (umc_8886_t *) priv;
+    uint8_t           ret = 0xff;

    if (func <= dev->max_func)
        ret = dev->pci_conf_sb[func][addr];
--- a/src/chipset/umc_hb4.c
+++ b/src/chipset/umc_hb4.c
@@ -333,8 +333,8 @@ hb4_write(UNUSED(int func), int addr, uint8_t val, void *priv)
 static uint8_t
 hb4_read(int func, int addr, void *priv)
 {
-    hb4_t  *dev = (hb4_t *) priv;
-    uint8_t ret = 0xff;
+    const hb4_t  *dev = (hb4_t *) priv;
+    uint8_t       ret = 0xff;

    if (func == 0)
        ret = dev->pci_conf[addr];
--- a/src/chipset/via_apollo.c
+++ b/src/chipset/via_apollo.c
@@ -671,8 +671,8 @@ via_apollo_host_bridge_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 via_apollo_read(int func, int addr, void *priv)
 {
-    via_apollo_t *dev = (via_apollo_t *) priv;
-    uint8_t       ret = 0xff;
+    const via_apollo_t *dev = (via_apollo_t *) priv;
+    uint8_t             ret = 0xff;

    switch (func) {
        case 0:
--- a/src/chipset/via_pipc.c
+++ b/src/chipset/via_pipc.c
@@ -41,6 +41,7 @@
 #include <86box/ddma.h>
 #include <86box/pci.h>
 #include <86box/pic.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 #include <86box/port_92.h>
 #include <86box/hdc.h>
@@ -750,8 +751,8 @@ pipc_codec_handlers(pipc_t *dev, uint8_t modem)
 static uint8_t
 pipc_fmnmi_read(uint16_t addr, void *priv)
 {
-    pipc_t *dev = (pipc_t *) priv;
-    uint8_t ret = dev->fmnmi_regs[addr & 0x03];
+    const pipc_t *dev = (pipc_t *) priv;
+    uint8_t       ret = dev->fmnmi_regs[addr & 0x03];

    pipc_log("PIPC: fmnmi_read(%02X) = %02X\n", addr & 0x03, ret);

@@ -786,7 +787,7 @@ pipc_fmnmi_handlers(pipc_t *dev, uint8_t modem)
 static uint8_t
 pipc_fm_read(uint16_t addr, void *priv)
 {
-    pipc_t *dev = (pipc_t *) priv;
+    const pipc_t *dev = (pipc_t *) priv;
 #ifdef VIA_PIPC_FM_EMULATION
    uint8_t ret = ((addr & 0x03) == 0x00) ? dev->fmnmi_status : 0x00;
 #else
@@ -1474,7 +1475,9 @@ pipc_write(int func, int addr, uint8_t val, void *priv)
            case 0xd2:
                if (dev->local == VIA_PIPC_686B)
                    smbus_piix4_setclock(dev->smbus, (val & 0x04) ? 65536 : 16384);
-                /* fall-through */
+#ifdef FALLTHROUGH_ANNOTATION
+                [[fallthrough]];
+#endif

            case 0x90:
            case 0x91:
--- a/src/chipset/via_vt82c49x.c
+++ b/src/chipset/via_vt82c49x.c
@@ -296,8 +296,8 @@ vt82c49x_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 vt82c49x_read(uint16_t addr, void *priv)
 {
-    uint8_t     ret = 0xff;
-    vt82c49x_t *dev = (vt82c49x_t *) priv;
+    uint8_t           ret = 0xff;
+    const vt82c49x_t *dev = (vt82c49x_t *) priv;

    switch (addr) {
        case 0xa9:
--- a/src/chipset/via_vt82c505.c
+++ b/src/chipset/via_vt82c505.c
@@ -126,8 +126,8 @@ vt82c505_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 vt82c505_read(int func, int addr, void *priv)
 {
-    vt82c505_t *dev = (vt82c505_t *) priv;
-    uint8_t     ret = 0xff;
+    const vt82c505_t *dev = (vt82c505_t *) priv;
+    uint8_t           ret = 0xff;

    if (func != 0)
        return ret;
@@ -151,8 +151,8 @@ vt82c505_out(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 vt82c505_in(uint16_t addr, void *priv)
 {
-    vt82c505_t *dev = (vt82c505_t *) priv;
-    uint8_t     ret = 0xff;
+    const vt82c505_t *dev = (vt82c505_t *) priv;
+    uint8_t           ret = 0xff;

    if ((addr == 0xa9) && (dev->index >= 0x80) && (dev->index <= 0x9f))
        ret = vt82c505_read(0, dev->index, priv);
--- a/src/chipset/vl82c480.c
+++ b/src/chipset/vl82c480.c
@@ -137,8 +137,8 @@ vl82c480_write(uint16_t addr, uint8_t val, void *priv)
 static uint8_t
 vl82c480_read(uint16_t addr, void *priv)
 {
-    vl82c480_t *dev = (vl82c480_t *) priv;
-    uint8_t     ret = 0xff;
+    const vl82c480_t *dev = (vl82c480_t *) priv;
+    uint8_t           ret = 0xff;

    switch (addr) {
        case 0xec:
--- a/src/chipset/wd76c10.c
+++ b/src/chipset/wd76c10.c
@@ -368,7 +368,8 @@ wd76c10_write(uint16_t addr, uint16_t val, void *priv)
 static uint16_t
 wd76c10_read(uint16_t addr, void *priv)
 {
-    wd76c10_t *dev = (wd76c10_t *) priv;
+    const wd76c10_t *dev = (wd76c10_t *) priv;
+
    wd76c10_log("WD76C10: R dev->regs[%04x]\n", addr);
    switch (addr) {
        case 0x1072:
--- a/src/config.c
+++ b/src/config.c
@@ -228,7 +228,7 @@ load_monitor(int monitor_index)
    ini_section_t cat;
    char          name[512];
    char          temp[512];
-    char         *p = NULL;
+    const char   *p = NULL;

    sprintf(name, "Monitor #%i", monitor_index + 1);
    sprintf(temp, "%i, %i, %i, %i", cx, cy, cw, ch);
@@ -256,7 +256,7 @@ load_machine(void)
 {
    ini_section_t cat = ini_find_section(config, "Machine");
    char         *p;
-    char         *migrate_from = NULL;
+    const char   *migrate_from = NULL;
    int           c;
    int           i;
    int           j;
@@ -448,7 +448,7 @@ load_machine(void)
                cpu_f = cpu_get_family(legacy_table_entry->family);
                if (cpu_f) {
                    /* Save the new values. */
-                    ini_section_set_string(cat, "cpu_family", (char *) legacy_table_entry->family);
+                    ini_section_set_string(cat, "cpu_family", legacy_table_entry->family);
                    ini_section_set_int(cat, "cpu_speed", legacy_table_entry->rspeed);
                    ini_section_set_double(cat, "cpu_multi", legacy_table_entry->multi);
                }
@@ -500,7 +500,7 @@ load_machine(void)

    cpu_waitstates = ini_section_get_int(cat, "cpu_waitstates", 0);

-    p        = (char *) ini_section_get_string(cat, "fpu_type", "none");
+    p        = ini_section_get_string(cat, "fpu_type", "none");
    fpu_type = fpu_get_type(cpu_f, cpu, p);

    mem_size = ini_section_get_int(cat, "mem_size", 64);
@@ -911,7 +911,7 @@ load_ports(void)
        lpt_ports[c].enabled = !!ini_section_get_int(cat, temp, (c == 0) ? 1 : 0);

        sprintf(temp, "lpt%d_device", c + 1);
-        p                   = (char *) ini_section_get_string(cat, temp, "none");
+        p                   = ini_section_get_string(cat, temp, "none");
        lpt_ports[c].device = lpt_device_get_from_internal_name(p);
    }

@@ -1557,7 +1557,7 @@ load_other_removable_devices(void)
    ini_section_t cat = ini_find_section(config, "Other removable devices");
    char          temp[512];
    char          tmp2[512];
-    char         *p;
+    const char   *p;
    char          s[512];
    unsigned int  board = 0;
    unsigned int  dev = 0;
@@ -2017,7 +2017,7 @@ save_general(void)
    char          temp[512];
    char          buffer[512] = { 0 };

-    char *va_name;
+    const char *va_name = NULL;

    ini_section_set_int(cat, "vid_resize", vid_resize);
    if (vid_resize == 0)
@@ -2216,7 +2216,7 @@ static void
 save_machine(void)
 {
    ini_section_t cat = ini_find_or_create_section(config, "Machine");
-    char         *p;
+    const char   *p;
    int           c;
    int           i = 0;
    int           legacy_mfg;
@@ -2226,7 +2226,7 @@ save_machine(void)
    p = machine_get_internal_name();
    ini_section_set_string(cat, "machine", p);

-    ini_section_set_string(cat, "cpu_family", (char *) cpu_f->internal_name);
+    ini_section_set_string(cat, "cpu_family", cpu_f->internal_name);
    ini_section_set_int(cat, "cpu_speed", cpu_f->cpus[cpu].rspeed);
    ini_section_set_double(cat, "cpu_multi", cpu_f->cpus[cpu].multi);
    if (cpu_override)
@@ -2247,14 +2247,14 @@ save_machine(void)
    }
    if (cpu_legacy_table[c].machine) {
        /* Look for a corresponding CPU entry. */
-        cpu_legacy_table_t *legacy_table_entry;
+        const cpu_legacy_table_t *legacy_table_entry;
        for (legacy_mfg = 0; legacy_mfg < 4; legacy_mfg++) {
            if (!cpu_legacy_table[c].tables[legacy_mfg])
                continue;

            i = 0;
            while (cpu_legacy_table[c].tables[legacy_mfg][i].family) {
-                legacy_table_entry = (cpu_legacy_table_t *) &cpu_legacy_table[c].tables[legacy_mfg][i];
+                legacy_table_entry = &cpu_legacy_table[c].tables[legacy_mfg][i];

                /* Match the family name, speed and multiplier. */
                if (!strcmp(cpu_f->internal_name, legacy_table_entry->family)) {
@@ -2294,7 +2294,7 @@ save_machine(void)
    if (fpu_type == 0)
        ini_section_delete_var(cat, "fpu_type");
    else
-        ini_section_set_string(cat, "fpu_type", (char *) fpu_get_internal_name(cpu_f, cpu, fpu_type));
+        ini_section_set_string(cat, "fpu_type", fpu_get_internal_name(cpu_f, cpu, fpu_type));

    // Write the mem_size explicitly to the setttings in order to help managers to display it without having the actual machine table
    ini_section_delete_var(cat, "mem_size");
@@ -2613,7 +2613,7 @@ save_ports(void)
            ini_section_delete_var(cat, temp);
        else
            ini_section_set_string(cat, temp,
-                                   (char *) lpt_device_get_internal_name(lpt_ports[c].device));
+                                   lpt_device_get_internal_name(lpt_ports[c].device));
    }

    ini_delete_section_if_empty(config, cat);
@@ -2738,7 +2738,7 @@ save_other_peripherals(void)
            ini_section_delete_var(cat, temp);
        else
            ini_section_set_string(cat, temp,
-                                   (char *) isamem_get_internal_name(isamem_type[c]));
+                                   isamem_get_internal_name(isamem_type[c]));
    }

    if (isartc_type == 0)
@@ -2836,7 +2836,7 @@ save_hard_disks(void)
        if (!hdd_is_valid(c) || (hdd[c].bus != HDD_BUS_IDE && hdd[c].bus != HDD_BUS_ESDI))
            ini_section_delete_var(cat, temp);
        else
-            ini_section_set_string(cat, temp, (char *) hdd_preset_get_internal_name(hdd[c].speed_preset));
+            ini_section_set_string(cat, temp, hdd_preset_get_internal_name(hdd[c].speed_preset));
    }

    ini_delete_section_if_empty(config, cat);
--- a/src/cpu/386_ops.h
+++ b/src/cpu/386_ops.h
@@ -223,10 +223,11 @@ extern void x386_dynarec_log(const char *fmt, ...);
 static int
 opVPCEXT(uint32_t fetchdat)
 {
-    uint8_t    b1, b2;
+    uint8_t    b1;
+    uint8_t    b2;
    uint16_t   cent;
    time_t     now;
-    struct tm *tm;
+    struct tm *tm = NULL;

    if (!is_vpc) /* only emulate this on Virtual PC machines */
        return ILLEGAL(fetchdat);
--- a/src/cpu/cpu.h
+++ b/src/cpu/cpu.h
@@ -133,13 +133,13 @@ enum {
 #    define LOOKUP_INV -1
 #endif

-typedef struct {
+typedef struct fpu_t {
    const char *name;
    const char *internal_name;
    const int   type;
 } FPU;

-typedef struct {
+typedef struct cpu_t {
    const char *name;
    uint64_t    cpu_type;
    const FPU  *fpus;
--- a/src/cpu/x86_ops_misc.h
+++ b/src/cpu/x86_ops_misc.h
@@ -51,8 +51,10 @@ opSETALC(uint32_t fetchdat)
 static int
 opF6_a16(uint32_t fetchdat)
 {
-    int      tempws, tempws2 = 0;
-    uint16_t tempw, src16;
+    int      tempws  = 0;
+    int      tempws2 = 0;
+    uint16_t tempw   = 0;
+    uint16_t src16;
    uint8_t  src, dst;
    int8_t   temps;

@@ -167,8 +169,10 @@ opF6_a16(uint32_t fetchdat)
 static int
 opF6_a32(uint32_t fetchdat)
 {
-    int      tempws, tempws2 = 0;
-    uint16_t tempw, src16;
+    int      tempws  = 0;
+    int      tempws2 = 0;
+    uint16_t tempw   = 0;
+    uint16_t src16;
    uint8_t  src, dst;
    int8_t   temps;

@@ -282,10 +286,13 @@ opF6_a32(uint32_t fetchdat)
 static int
 opF7_w_a16(uint32_t fetchdat)
 {
-    uint32_t templ, templ2   = 0;
-    int      tempws, tempws2 = 0;
+    uint32_t templ;
+    uint32_t templ2  = 0;
+    int      tempws;
+    int      tempws2 = 0;
    int16_t  temps16;
-    uint16_t src, dst;
+    uint16_t src;
+    uint16_t dst;

    fetch_ea_16(fetchdat);
    if (cpu_mod != 3)
@@ -392,8 +399,10 @@ opF7_w_a16(uint32_t fetchdat)
 static int
 opF7_w_a32(uint32_t fetchdat)
 {
-    uint32_t templ, templ2   = 0;
-    int      tempws, tempws2 = 1;
+    uint32_t templ;
+    uint32_t templ2  = 0;
+    int      tempws;
+    int      tempws2 = 1;
    int16_t  temps16;
    uint16_t src, dst;

--- a/src/cpu/x87_ops.h
+++ b/src/cpu/x87_ops.h
@@ -481,6 +481,8 @@ typedef union {
 #    define FP_TAG_VALID_N cpu_state.tag[(cpu_state.TOP + 1) & 7] &= ~TAG_UINT64
 #endif

+#include "softfloat/softfloat-specialize.h"
+
 #include "x87_ops_sf_arith.h"
 #include "x87_ops_sf_compare.h"
 #include "x87_ops_sf_const.h"
--- a/src/ddma.c
+++ b/src/ddma.c
@@ -57,10 +57,10 @@ ddma_log(const char *fmt, ...)
 static uint8_t
 ddma_reg_read(uint16_t addr, void *priv)
 {
-    ddma_channel_t *dev  = (ddma_channel_t *) priv;
-    uint8_t         ret  = 0xff;
-    int             ch   = dev->channel;
-    int             dmab = (ch >= 4) ? 0xc0 : 0x00;
+    const ddma_channel_t *dev  = (ddma_channel_t *) priv;
+    uint8_t               ret  = 0xff;
+    int                   ch   = dev->channel;
+    uint8_t               dmab = (ch >= 4) ? 0xc0 : 0x00;

    switch (addr & 0x0f) {
        case 0x00:
@@ -92,10 +92,10 @@ ddma_reg_read(uint16_t addr, void *priv)
 static void
 ddma_reg_write(uint16_t addr, uint8_t val, void *priv)
 {
-    ddma_channel_t *dev          = (ddma_channel_t *) priv;
-    int             ch           = dev->channel;
-    int             page_regs[4] = { 7, 3, 1, 2 };
-    int             dmab = (ch >= 4) ? 0xc0 : 0x00;
+    const ddma_channel_t *dev          = (ddma_channel_t *) priv;
+    int                   ch           = dev->channel;
+    uint8_t               page_regs[4] = { 7, 3, 1, 2 };
+    uint8_t               dmab = (ch >= 4) ? 0xc0 : 0x00;

    switch (addr & 0x0f) {
        case 0x00:
--- a/src/device.c
+++ b/src/device.c
@@ -90,8 +90,8 @@ device_init(void)
 void
 device_set_context(device_context_t *c, const device_t *dev, int inst)
 {
-    void *sec;
-    void *single_sec;
+    const void *sec;
+    void       *single_sec;

    memset(c, 0, sizeof(device_context_t));
    c->dev      = dev;
@@ -143,7 +143,7 @@ device_add_common(const device_t *dev, const device_t *cd, void *p, void *params
    int   c;

    for (c = 0; c < 256; c++) {
-        if (!inst && (devices[c] == (device_t *) dev)) {
+        if (!inst && (devices[c] == dev)) {
            device_log("DEVICE: device already exists!\n");
            return (NULL);
        }
@@ -343,23 +343,23 @@ device_get_priv(const device_t *dev)
 int
 device_available(const device_t *dev)
 {
-    device_config_t      *config = NULL;
-    device_config_bios_t *bios   = NULL;
-    int                   roms_present = 0;
-    int                   i = 0;
+    const device_config_t      *config = NULL;
+    const device_config_bios_t *bios   = NULL;
+    int                         roms_present = 0;
+    int                         i = 0;

    if (dev != NULL) {
-        config = (device_config_t *) dev->config;
+        config = dev->config;
        if (config != NULL) {
            while (config->type != -1) {
                if (config->type == CONFIG_BIOS) {
-                    bios = (device_config_bios_t *) config->bios;
+                    bios = (const device_config_bios_t *) config->bios;

                    /* Go through the ROM's in the device configuration. */
                    while (bios->files_no != 0) {
                        i = 0;
                        for (int bf = 0; bf < bios->files_no; bf++)
-                            i += !!rom_present((char *) bios->files[bf]);
+                            i += !!rom_present(bios->files[bf]);
                        if (i == bios->files_no)
                            roms_present++;
                        bios++;
@@ -385,15 +385,15 @@ device_available(const device_t *dev)
 const char *
 device_get_bios_file(const device_t *dev, const char *internal_name, int file_no)
 {
-    device_config_t      *config = NULL;
-    device_config_bios_t *bios   = NULL;
+    const device_config_t      *config = NULL;
+    const device_config_bios_t *bios   = NULL;

    if (dev != NULL) {
-        config = (device_config_t *) dev->config;
+        config = dev->config;
        if (config != NULL) {
            while (config->type != -1) {
                if (config->type == CONFIG_BIOS) {
-                    bios = (device_config_bios_t *) config->bios;
+                    bios = config->bios;

                    /* Go through the ROM's in the device configuration. */
                    while (bios->files_no != 0) {
@@ -418,8 +418,8 @@ device_get_bios_file(const device_t *dev, const char *internal_name, int file_no
 int
 device_has_config(const device_t *dev)
 {
-    int              c = 0;
-    device_config_t *config;
+    int                    c = 0;
+    const device_config_t *config;

    if (dev == NULL)
        return 0;
@@ -427,7 +427,7 @@ device_has_config(const device_t *dev)
    if (dev->config == NULL)
        return 0;

-    config = (device_config_t *) dev->config;
+    config = dev->config;

    while (config->type != -1) {
        if (config->type != CONFIG_MAC)
@@ -472,10 +472,10 @@ device_register_pci_slot(const device_t *dev, int device, int type, int inta, in
 void
 device_get_name(const device_t *dev, int bus, char *name)
 {
-    char *sbus = NULL;
-    char *fbus;
-    char *tname;
-    char  pbus[8] = { 0 };
+    const char *sbus = NULL;
+    const char *fbus;
+    char       *tname;
+    char        pbus[8] = { 0 };

    if (dev == NULL)
        return;
--- a/src/device/cartridge.c
+++ b/src/device/cartridge.c
@@ -61,7 +61,7 @@ cartridge_log(const char *fmt, ...)
 static uint8_t
 cart_read(uint32_t addr, void *priv)
 {
-    cart_t *dev = (cart_t *) priv;
+    const cart_t *dev = (cart_t *) priv;

    return dev->buf[addr - dev->base];
 }
--- a/src/device/hwm_lm78.c
+++ b/src/device/hwm_lm78.c
@@ -421,8 +421,8 @@ lm78_i2c_read(UNUSED(void *bus), UNUSED(uint8_t addr), void *priv)
 uint8_t
 lm78_as99127f_read(void *priv, uint8_t reg)
 {
-    lm78_t *dev = (lm78_t *) priv;
-    uint8_t ret = dev->as99127f.regs[1][reg & 0x7f];
+    const lm78_t *dev = (lm78_t *) priv;
+    uint8_t       ret = dev->as99127f.regs[1][reg & 0x7f];

    lm78_log("LM78: read(%02X, AS99127F) = %02X\n", reg, ret);

--- a/src/device/hwm_vt82c686.c
+++ b/src/device/hwm_vt82c686.c
@@ -48,8 +48,8 @@ static void vt82c686_reset(vt82c686_t *dev, uint8_t initialization);
 static uint8_t
 vt82c686_read(uint16_t addr, void *priv)
 {
-    vt82c686_t *dev = (vt82c686_t *) priv;
-    uint8_t     ret;
+    const vt82c686_t *dev = (vt82c686_t *) priv;
+    uint8_t           ret;

    addr -= dev->io_base;

--- a/src/device/i2c.c
+++ b/src/device/i2c.c
@@ -205,9 +205,9 @@ i2c_handler(int set, void *bus_handle, uint8_t base, int size,
 uint8_t
 i2c_start(void *bus_handle, uint8_t addr, uint8_t read)
 {
-    uint8_t    ret = 0;
-    i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
-    i2c_t     *p;
+    uint8_t          ret = 0;
+    const i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
+    i2c_t           *p;

    if (!bus)
        return ret;
@@ -230,9 +230,9 @@ i2c_start(void *bus_handle, uint8_t addr, uint8_t read)
 uint8_t
 i2c_read(void *bus_handle, uint8_t addr)
 {
-    uint8_t    ret = 0;
-    i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
-    i2c_t     *p;
+    uint8_t          ret = 0;
+    const i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
+    i2c_t           *p;

    if (!bus)
        return ret;
@@ -256,9 +256,9 @@ i2c_read(void *bus_handle, uint8_t addr)
 uint8_t
 i2c_write(void *bus_handle, uint8_t addr, uint8_t data)
 {
-    uint8_t    ret = 0;
-    i2c_t     *p;
-    i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
+    uint8_t          ret = 0;
+    i2c_t           *p;
+    const i2c_bus_t *bus = (i2c_bus_t *) bus_handle;

    if (!bus)
        return ret;
@@ -281,8 +281,8 @@ i2c_write(void *bus_handle, uint8_t addr, uint8_t data)
 void
 i2c_stop(void *bus_handle, uint8_t addr)
 {
-    i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
-    i2c_t     *p;
+    const i2c_bus_t *bus = (i2c_bus_t *) bus_handle;
+    i2c_t           *p;

    if (!bus)
        return;
--- a/src/device/i2c_gpio.c
+++ b/src/device/i2c_gpio.c
@@ -171,14 +171,16 @@ i2c_gpio_set(void *dev_handle, uint8_t scl, uint8_t sda)
 uint8_t
 i2c_gpio_get_scl(void *dev_handle)
 {
-    i2c_gpio_t *dev = (i2c_gpio_t *) dev_handle;
+    const i2c_gpio_t *dev = (i2c_gpio_t *) dev_handle;
+
    return dev->prev_scl;
 }

 uint8_t
 i2c_gpio_get_sda(void *dev_handle)
 {
-    i2c_gpio_t *dev = (i2c_gpio_t *) dev_handle;
+    const i2c_gpio_t *dev = (i2c_gpio_t *) dev_handle;
+
    i2c_gpio_log(3, "I2C GPIO %s: read myscl=%d mysda=%d slavesda=%d\n", dev->bus_name, dev->prev_scl, dev->prev_sda, dev->slave_sda);
    return dev->prev_sda && dev->slave_sda;
 }
--- a/src/device/ibm_5161.c
+++ b/src/device/ibm_5161.c
@@ -45,8 +45,8 @@ ibm_5161_out(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 ibm_5161_in(uint16_t port, void *priv)
 {
-    ibm_5161_t *dev = (ibm_5161_t *) priv;
-    uint8_t     ret = 0xff;
+    const ibm_5161_t *dev = (ibm_5161_t *) priv;
+    uint8_t           ret = 0xff;

    ret = dev->regs[port & 0x0007];

--- a/src/device/isamem.c
+++ b/src/device/isamem.c
@@ -288,9 +288,9 @@ ems_writew(uint32_t addr, uint16_t val, void *priv)
 static uint8_t
 ems_read(uint16_t port, void *priv)
 {
-    memdev_t *dev = (memdev_t *) priv;
-    uint8_t   ret = 0xff;
-    int       vpage;
+    const memdev_t *dev = (memdev_t *) priv;
+    uint8_t         ret = 0xff;
+    int             vpage;

    /* Get the viewport page number. */
    vpage = (port / EMS_PGSIZE);
--- a/src/device/isapnp.c
+++ b/src/device/isapnp.c
@@ -259,7 +259,8 @@ isapnp_reset_ld_regs(isapnp_device_t *ld)
 static uint8_t
 isapnp_read_rangecheck(UNUSED(uint16_t addr), void *priv)
 {
-    isapnp_device_t *dev = (isapnp_device_t *) priv;
+    const isapnp_device_t *dev = (isapnp_device_t *) priv;
+
    return (dev->regs[0x31] & 0x01) ? 0x55 : 0xaa;
 }

--- a/src/device/isartc.c
+++ b/src/device/isartc.c
@@ -191,11 +191,11 @@ mm67_chkalrm(nvr_t *nvr, int8_t addr)
 static void
 mm67_tick(nvr_t *nvr)
 {
-    rtcdev_t *dev  = (rtcdev_t *) nvr->data;
-    uint8_t  *regs = nvr->regs;
-    int       mon;
-    int       year;
-    int       f = 0;
+    const rtcdev_t *dev  = (rtcdev_t *) nvr->data;
+    uint8_t        *regs = nvr->regs;
+    int             mon;
+    int             year;
+    int             f = 0;

    /* Update and set interrupt if needed. */
    regs[MM67_SEC] = RTC_BCDINC(nvr->regs[MM67_SEC], 1);
@@ -295,8 +295,8 @@ mm67_tick(nvr_t *nvr)
 static void
 mm67_time_get(nvr_t *nvr, struct tm *tm)
 {
-    rtcdev_t *dev  = (rtcdev_t *) nvr->data;
-    uint8_t  *regs = nvr->regs;
+    const rtcdev_t *dev  = (rtcdev_t *) nvr->data;
+    const uint8_t  *regs = nvr->regs;

    /* NVR is in BCD data mode. */
    tm->tm_sec  = RTC_DCB(regs[MM67_SEC]);
@@ -325,9 +325,9 @@ mm67_time_get(nvr_t *nvr, struct tm *tm)
 static void
 mm67_time_set(nvr_t *nvr, struct tm *tm)
 {
-    rtcdev_t *dev  = (rtcdev_t *) nvr->data;
-    uint8_t  *regs = nvr->regs;
-    int       year;
+    const rtcdev_t *dev  = (rtcdev_t *) nvr->data;
+    uint8_t        *regs = nvr->regs;
+    int             year;

    /* NVR is in BCD data mode. */
    regs[MM67_SEC]  = RTC_BCD(tm->tm_sec);
@@ -608,9 +608,6 @@ isartc_close(void *priv)
    io_removehandler(dev->base_addr, dev->base_addrsz,
                     dev->f_rd, NULL, NULL, dev->f_wr, NULL, NULL, dev);

-    if (dev->nvr.fn != NULL)
-        free(dev->nvr.fn);
-
    free(dev);
 }

--- a/src/device/kbc_at.c
+++ b/src/device/kbc_at.c
@@ -29,6 +29,7 @@
 #include <86box/io.h>
 #include <86box/pic.h>
 #include <86box/pit.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 #include <86box/ppi.h>
 #include <86box/mem.h>
@@ -463,7 +464,9 @@ kbc_at_poll_at(atkbc_t *dev)
        case STATE_KBC_AMI_OUT:
            if (dev->status & STAT_OFULL)
                break;
-            /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case STATE_MAIN_IBF:
        default:
 at_main_ibf:
@@ -586,7 +589,9 @@ kbc_at_poll_ps2(atkbc_t *dev)
        case STATE_KBC_AMI_OUT:
            if (dev->status & STAT_OFULL)
                break;
-            /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case STATE_MAIN_IBF:
        default:
 ps2_main_ibf:
@@ -1027,6 +1032,9 @@ write64_generic(void *priv, uint8_t val)
            kbc_at_log("ATkbc: pulse %01X\n", val & 0x0f);
            pulse_output(dev, val & 0x0f);
            return 0;
+
+        default:
+            break;
    }

    kbc_at_log("ATkbc: bad command %02X\n", val);
@@ -1328,12 +1336,13 @@ write64_siemens(void *priv, uint8_t val)
 static uint8_t
 write60_quadtel(void *priv, UNUSED(uint8_t val))
 {
-    atkbc_t *dev = (atkbc_t *) priv;
+    const atkbc_t *dev = (atkbc_t *) priv;

    switch (dev->command) {
        case 0xcf: /*??? - sent by MegaPC BIOS*/
            kbc_at_log("ATkbc: ??? - sent by MegaPC BIOS\n");
            return 0;
+
        default:
            break;
    }
@@ -1392,7 +1401,7 @@ write64_quadtel(void *priv, uint8_t val)
 static uint8_t
 write60_toshiba(void *priv, uint8_t val)
 {
-    atkbc_t *dev = (atkbc_t *) priv;
+    const atkbc_t *dev = (atkbc_t *) priv;

    switch (dev->command) {
        case 0xb6: /* T3100e - set color/mono switch */
--- a/src/device/kbc_at_dev.c
+++ b/src/device/kbc_at_dev.c
@@ -38,6 +38,7 @@
 #include <86box/snd_speaker.h>
 #include <86box/video.h>
 #include <86box/keyboard.h>
+#include <86box/plat_fallthrough.h>

 #ifdef ENABLE_KBC_AT_DEV_LOG
 int kbc_at_dev_do_log = ENABLE_KBC_AT_DEV_LOG;
@@ -135,7 +136,9 @@ kbc_at_dev_poll(void *priv)
                dev->port->wantcmd    = 0;
                break;
            }
-            /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case DEV_STATE_MAIN_WANT_IN:
            /* Output command response and then return to main loop #2. */
            if ((dev->port->out_new == -1) && (dev->cmd_queue_start != dev->cmd_queue_end)) {
--- a/src/device/keyboard.c
+++ b/src/device/keyboard.c
@@ -87,8 +87,8 @@ fake_shift_needed(uint16_t scan)
 void
 key_process(uint16_t scan, int down)
 {
-    scancode *codes = scan_table;
-    int       c;
+    const scancode *codes = scan_table;
+    int             c;

    if (!codes)
        return;
@@ -222,7 +222,7 @@ keyboard_input(int down, uint16_t scan)
 static uint8_t
 keyboard_do_break(uint16_t scan)
 {
-    scancode *codes = scan_table;
+    const scancode *codes = scan_table;

    /* TODO: The keyboard controller needs to report the AT flag to us here. */
    if (is286 && ((keyboard_mode & 3) == 3)) {
@@ -266,7 +266,7 @@ keyboard_get_states(uint8_t *cl, uint8_t *nl, uint8_t *sl)
 void
 keyboard_set_states(uint8_t cl, uint8_t nl, uint8_t sl)
 {
-    scancode *codes = scan_table;
+    const scancode *codes = scan_table;

    int i;

@@ -320,7 +320,7 @@ keyboard_isfsenter(void)
 }

 int
-keyboard_isfsenter_down(void)
+keyboard_isfsenter_up(void)
 {
    return (!recv_key[0x01d] && !recv_key[0x11d] && !recv_key[0x038] && !recv_key[0x138] && !recv_key[0x049] && !recv_key[0x149]);
 }
@@ -333,7 +333,7 @@ keyboard_isfsexit(void)
 }

 int
-keyboard_isfsexit_down(void)
+keyboard_isfsexit_up(void)
 {
    return (!recv_key[0x01d] && !recv_key[0x11d] && !recv_key[0x038] && !recv_key[0x138] && !recv_key[0x051] && !recv_key[0x151]);
 }
--- a/src/device/keyboard_xt.c
+++ b/src/device/keyboard_xt.c
@@ -594,8 +594,8 @@ kbd_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 kbd_read(uint16_t port, void *priv)
 {
-    xtkbd_t *kbd = (xtkbd_t *) priv;
-    uint8_t  ret = 0xff;
+    const xtkbd_t *kbd = (xtkbd_t *) priv;
+    uint8_t        ret = 0xff;

    switch (port) {
        case 0x60: /* Keyboard Data Register  (aka Port A) */
--- a/src/device/mouse_bus.c
+++ b/src/device/mouse_bus.c
@@ -226,7 +226,6 @@ lt_read(uint16_t port, void *priv)
                return (dev->control_val | 0x0F) & ~IRQ_MASK;
            else
                return 0xff;
-            break;

        default:
            break;
--- a/src/device/mouse_serial.c
+++ b/src/device/mouse_serial.c
@@ -26,6 +26,7 @@
 #include <86box/timer.h>
 #include <86box/serial.h>
 #include <86box/mouse.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>

 #define SERMOUSE_PORT 0 /* attach to Serial0 */
@@ -507,7 +508,9 @@ sermouse_command_timer(void *priv)
            break;
        case PHASE_ACK:
            serial_write_fifo(dev->serial, 0x06);
-            /* FALLTHROUGH */
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case PHASE_BAUD_RATE:
            sermouse_command_phase_idle(dev);
            sermouse_timer_on(dev, dev->report_period, 1);
@@ -645,7 +648,9 @@ ltsermouse_write(UNUSED(struct serial_s *serial), void *priv, uint8_t data)
                switch (data) {
                    default:
                        mouse_serial_log("Serial mouse: Invalid period %02X, using 1200 bps\n", data);
-                        /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                        [[fallthrough]];
+#endif
                    case 0x6E:
                        dev->transmit_period = sermouse_transmit_period(dev, 1200, -1);
                        break;
--- a/src/device/pci_bridge.c
+++ b/src/device/pci_bridge.c
@@ -363,8 +363,8 @@ pci_bridge_write(int func, int addr, uint8_t val, void *priv)
 static uint8_t
 pci_bridge_read(int func, int addr, void *priv)
 {
-    pci_bridge_t *dev = (pci_bridge_t *) priv;
-    uint8_t       ret;
+    const pci_bridge_t *dev = (pci_bridge_t *) priv;
+    uint8_t             ret;

    if (func > 0)
        ret = 0xff;
--- a/src/device/phoenix_486_jumper.c
+++ b/src/device/phoenix_486_jumper.c
@@ -78,7 +78,8 @@ phoenix_486_jumper_write(UNUSED(uint16_t addr), uint8_t val, void *priv)
 static uint8_t
 phoenix_486_jumper_read(UNUSED(uint16_t addr), void *priv)
 {
-    phoenix_486_jumper_t *dev = (phoenix_486_jumper_t *) priv;
+    const phoenix_486_jumper_t *dev = (phoenix_486_jumper_t *) priv;
+
    phoenix_486_jumper_log("Phoenix 486 Jumper: Read %02x\n", dev->jumper);
    return dev->jumper;
 }
--- a/src/device/smbus_ali7101.c
+++ b/src/device/smbus_ali7101.c
@@ -28,6 +28,7 @@
 #include <86box/timer.h>
 #include <86box/i2c.h>
 #include <86box/smbus.h>
+#include <86box/plat_fallthrough.h>

 #ifdef ENABLE_SMBUS_ALI7101_LOG
 int smbus_ali7101_do_log = ENABLE_SMBUS_ALI7101_LOG;
@@ -193,7 +194,9 @@ smbus_ali7101_write(uint16_t addr, uint8_t val, void *priv)
                case 0x4:          /* block R/W */
                    timer_bytes++; /* count the SMBus length byte now */

-                    /* fall-through */
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                default:                   /* unknown */
                    dev->next_stat = 0x20; /* raise DEV_ERR */
--- a/src/device/smbus_piix4.c
+++ b/src/device/smbus_piix4.c
@@ -27,6 +27,7 @@
 #include <86box/timer.h>
 #include <86box/i2c.h>
 #include <86box/smbus.h>
+#include <86box/plat_fallthrough.h>

 #ifdef ENABLE_SMBUS_PIIX4_LOG
 int smbus_piix4_do_log = ENABLE_SMBUS_PIIX4_LOG;
@@ -195,7 +196,9 @@ smbus_piix4_write(uint16_t addr, uint8_t val, void *priv)
                            timer_bytes++;
                        }

-                        /* fall-through */
+#ifdef FALLTHROUGH_ANNOTATION
+                        [[fallthrough]];
+#endif

                    case 0xc:        /* I2C process call */
                        if (!read) { /* word write (only when writing) */
@@ -214,7 +217,9 @@ smbus_piix4_write(uint16_t addr, uint8_t val, void *priv)
                    case 0x5:          /* block R/W */
                        timer_bytes++; /* count the SMBus length byte now */

-                        /* fall-through */
+#ifdef FALLTHROUGH_ANNOTATION
+                        [[fallthrough]];
+#endif

                    case 0xd: /* I2C block R/W */
                        i2c_write(i2c_smbus, smbus_addr, dev->cmd);
@@ -247,7 +252,9 @@ smbus_piix4_write(uint16_t addr, uint8_t val, void *priv)
                        i2c_write(i2c_smbus, smbus_addr, dev->cmd);
                        timer_bytes++;

-                        /* fall-through */
+#ifdef FALLTHROUGH_ANNOTATION
+                        [[fallthrough]];
+#endif

                    case 0xe:        /* I2C with 7-bit address */
                        if (!read) { /* word write (only when writing) */
--- a/src/disk/hdc_esdi_at.c
+++ b/src/disk/hdc_esdi_at.c
@@ -173,13 +173,13 @@ esdi_get_xfer_time(UNUSED(esdi_t *esdi), int size)
 static int
 get_sector(esdi_t *esdi, off64_t *addr)
 {
-    drive_t *drive   = &esdi->drives[esdi->drive_sel];
-    int      heads   = drive->cfg_hpc;
-    int      sectors = drive->cfg_spt;
-    int      c;
-    int      h;
-    int      s;
-    int      sector;
+    const drive_t *drive   = &esdi->drives[esdi->drive_sel];
+    int            heads   = drive->cfg_hpc;
+    int            sectors = drive->cfg_spt;
+    int            c;
+    int            h;
+    int            s;
+    int            sector;

    if (esdi->head > heads) {
        esdi_at_log("esdi_get_sector: past end of configured heads\n");
@@ -338,7 +338,9 @@ esdi_write(uint16_t port, uint8_t val, void *priv)
                            esdi->command &= ~0x03;
                            if (val & 0x02)
                                fatal("Read with ECC\n");
-                            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                            [[fallthrough]];
+#endif

                        case 0xa0:
                            esdi->status = STAT_BUSY;
@@ -397,7 +399,9 @@ esdi_write(uint16_t port, uint8_t val, void *priv)

                        default:
                            esdi_at_log("WD1007: bad command %02X\n", val);
-                            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                            [[fallthrough]];
+#endif
                        case 0xe8: /*???*/
                            esdi->status = STAT_BUSY;
                            esdi_set_callback(esdi, 200 * HDC_TIME);
@@ -878,8 +882,8 @@ wd1007vse1_init(UNUSED(const device_t *info))
 static void
 wd1007vse1_close(void *priv)
 {
-    esdi_t  *esdi = (esdi_t *) priv;
-    drive_t *drive;
+    esdi_t        *esdi = (esdi_t *) priv;
+    const drive_t *drive;

    for (uint8_t d = 0; d < 2; d++) {
        drive = &esdi->drives[d];
--- a/src/disk/hdc_esdi_mca.c
+++ b/src/disk/hdc_esdi_mca.c
@@ -352,10 +352,10 @@ complete_command_status(esdi_t *dev)
 static void
 esdi_callback(void *priv)
 {
-    esdi_t  *dev = (esdi_t *) priv;
-    drive_t *drive;
-    int      val;
-    double   cmd_time = 0.0;
+    esdi_t        *dev = (esdi_t *) priv;
+    const drive_t *drive;
+    int            val;
+    double         cmd_time = 0.0;

    esdi_mca_set_callback(dev, 0);

@@ -1059,7 +1059,7 @@ esdi_writew(uint16_t port, uint16_t val, void *priv)
 static uint8_t
 esdi_mca_read(int port, void *priv)
 {
-    esdi_t *dev = (esdi_t *) priv;
+    const esdi_t *dev = (esdi_t *) priv;

    esdi_mca_log("ESDI: mcard(%04x)\n", port);

@@ -1132,7 +1132,7 @@ esdi_mca_write(int port, uint8_t val, void *priv)
 static uint8_t
 esdi_mca_feedb(void *priv)
 {
-    esdi_t *dev = (esdi_t *) priv;
+    const esdi_t *dev = (esdi_t *) priv;

    return (dev->pos_regs[2] & 1);
 }
@@ -1210,8 +1210,8 @@ esdi_init(UNUSED(const device_t *info))
 static void
 esdi_close(void *priv)
 {
-    esdi_t  *dev = (esdi_t *) priv;
-    drive_t *drive;
+    esdi_t        *dev = (esdi_t *) priv;
+    const drive_t *drive;

    dev->drives[0].present = dev->drives[1].present = 0;

--- a/src/disk/hdc_ide.c
+++ b/src/disk/hdc_ide.c
@@ -597,13 +597,13 @@ ide_hd_identify(ide_t *ide)
 static void
 ide_identify(ide_t *ide)
 {
-    int    d;
-    int    i;
-    int    max_pio;
-    int    max_sdma;
-    int    max_mdma;
-    int    max_udma;
-    ide_t *ide_other = ide_drives[ide->channel ^ 1];
+    int          d;
+    int          i;
+    int          max_pio;
+    int          max_sdma;
+    int          max_mdma;
+    int          max_udma;
+    const ide_t *ide_other = ide_drives[ide->channel ^ 1];

    ide_log("IDE IDENTIFY or IDENTIFY PACKET DEVICE on board %i (channel %i)\n", ide->board, ide->channel);

@@ -1114,8 +1114,8 @@ ide_atapi_packet_read(ide_t *ide, int length)
 {
    scsi_common_t *dev = ide->sc;

-    uint16_t *bufferw;
-    uint32_t *bufferl;
+    const uint16_t *bufferw;
+    const uint32_t *bufferl;

    uint32_t temp = 0;

@@ -1311,7 +1311,7 @@ ide_writew(uint16_t addr, uint16_t val, void *priv)
 static void
 ide_writel(uint16_t addr, uint32_t val, void *priv)
 {
-    ide_board_t *dev = (ide_board_t *) priv;
+    const ide_board_t *dev = (ide_board_t *) priv;

    ide_t *ide;
    int    ch;
@@ -1655,7 +1655,9 @@ ide_writeb(uint16_t addr, uint8_t val, void *priv)
                       disabled, the Read Multiple operation is rejected with an Aborted Com-
                       mand error. */
                    ide->blockcount = 0;
-                    /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                case WIN_READ:
                case WIN_READ_NORETRY:
@@ -1704,7 +1706,9 @@ ide_writeb(uint16_t addr, uint8_t val, void *priv)
                    /* Turn on the activity indicator *here* so that it gets turned on
                       less times. */
                    ui_sb_update_icon(SB_HDD | hdd[ide->hdd_num].bus, 1);
-                    /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                case WIN_WRITE:
                case WIN_WRITE_NORETRY:
@@ -1843,6 +1847,9 @@ ide_bad_command:
                    return;
            }
            return;
+
+        default:
+            break;
    }
 }

@@ -1864,9 +1871,9 @@ ide_read_data(ide_t *ide, int length)
        }
    }

-    uint8_t  *idebufferb = (uint8_t *) ide->buffer;
-    uint16_t *idebufferw = ide->buffer;
-    uint32_t *idebufferl = (uint32_t *) ide->buffer;
+    const uint8_t  *idebufferb = (uint8_t *) ide->buffer;
+    const uint16_t *idebufferw = ide->buffer;
+    const uint32_t *idebufferl = (uint32_t *) ide->buffer;

    if (ide->command == WIN_PACKETCMD) {
        ide->pos = 0;
@@ -1946,7 +1953,7 @@ ide_status(ide_t *ide, ide_t *ide_other, int ch)
 uint8_t
 ide_readb(uint16_t addr, void *priv)
 {
-    ide_board_t *dev = (ide_board_t *) priv;
+    const ide_board_t *dev = (ide_board_t *) priv;

    int    ch;
    int    absent = 0;
@@ -2062,6 +2069,9 @@ ide_readb(uint16_t addr, void *priv)
            ide_irq_lower(ide);
            temp = ide_status(ide, ide_drives[ch ^ 1], ch);
            break;
+
+        default:
+            break;
    }

    ide_log("ide_readb(%04X, %08X) = %02X\n", addr, priv, temp);
@@ -2073,7 +2083,7 @@ ide_read_alt_status(UNUSED(uint16_t addr), void *priv)
 {
    uint8_t temp = 0xff;

-    ide_board_t *dev = (ide_board_t *) priv;
+    const ide_board_t *dev = (ide_board_t *) priv;

    ide_t *ide;
    int    ch;
@@ -2094,7 +2104,7 @@ ide_readw(uint16_t addr, void *priv)
 {
    uint16_t temp = 0xffff;

-    ide_board_t *dev = (ide_board_t *) priv;
+    const ide_board_t *dev = (ide_board_t *) priv;

    ide_t *ide;
    int    ch;
@@ -2124,7 +2134,7 @@ ide_readl(uint16_t addr, void *priv)
    uint16_t temp2;
    uint32_t temp = 0xffffffff;

-    ide_board_t *dev = (ide_board_t *) priv;
+    const ide_board_t *dev = (ide_board_t *) priv;

    ide_t *ide;
    int    ch;
@@ -2620,11 +2630,11 @@ id_not_found:
 uint8_t
 ide_read_ali_75(void)
 {
-    ide_t  *ide0;
-    ide_t *ide1;
-    int     ch0;
-    int     ch1;
-    uint8_t ret = 0x00;
+    const ide_t *ide0;
+    const ide_t *ide1;
+    int          ch0;
+    int          ch1;
+    uint8_t      ret = 0x00;

    ch0  = ide_boards[0]->cur_dev;
    ch1  = ide_boards[1]->cur_dev;
@@ -2646,11 +2656,11 @@ ide_read_ali_75(void)
 uint8_t
 ide_read_ali_76(void)
 {
-    ide_t  *ide0;
-    ide_t  *ide1;
-    int     ch0;
-    int     ch1;
-    uint8_t ret = 0x00;
+    const ide_t  *ide0;
+    const ide_t  *ide1;
+    int           ch0;
+    int           ch1;
+    uint8_t       ret = 0x00;

    ch0  = ide_boards[0]->cur_dev;
    ch1  = ide_boards[1]->cur_dev;
--- a/src/disk/hdc_ide_cmd640.c
+++ b/src/disk/hdc_ide_cmd640.c
@@ -41,7 +41,7 @@ typedef struct cmd640_t {
    uint8_t  vlb_idx;
    uint8_t  id;
    uint8_t  in_cfg;
-    uint8_t  single_channel;
+    uint8_t  channels;
    uint8_t  pci, regs[256];
    uint32_t local;
    int      slot;
@@ -89,6 +89,10 @@ cmd640_set_irq(int channel, void *priv)
    }

    channel &= 0x01;
+
+    if (!(dev->channels & (1 << channel)))
+        return;
+
    if (irq) {
        if (dev->irq_mode[channel] == 1)
            pci_set_irq(dev->slot, dev->irq_pin);
@@ -108,40 +112,41 @@ cmd640_ide_handlers(cmd640_t *dev)
    uint16_t main;
    uint16_t side;

-    ide_pri_disable();
+    if (dev->channels & 0x01) {
+        ide_pri_disable();

-    if ((dev->regs[0x09] & 0x01) && (dev->regs[0x50] & 0x40)) {
-        main = (dev->regs[0x11] << 8) | (dev->regs[0x10] & 0xf8);
-        side = ((dev->regs[0x15] << 8) | (dev->regs[0x14] & 0xfc)) + 2;
-    } else {
-        main = 0x1f0;
-        side = 0x3f6;
+        if ((dev->regs[0x09] & 0x01) && (dev->regs[0x50] & 0x40)) {
+            main = (dev->regs[0x11] << 8) | (dev->regs[0x10] & 0xf8);
+            side = ((dev->regs[0x15] << 8) | (dev->regs[0x14] & 0xfc)) + 2;
+        } else {
+            main = 0x1f0;
+            side = 0x3f6;
+        }
+
+        ide_set_base(0, main);
+        ide_set_side(0, side);
+
+        if (dev->regs[0x04] & 0x01)
+            ide_pri_enable();
    }

-    ide_set_base(0, main);
-    ide_set_side(0, side);
+    if (dev->channels & 0x02) {
+        ide_sec_disable();

-    if (dev->regs[0x04] & 0x01)
-        ide_pri_enable();
+        if ((dev->regs[0x09] & 0x04) && (dev->regs[0x50] & 0x40)) {
+            main = (dev->regs[0x19] << 8) | (dev->regs[0x18] & 0xf8);
+            side = ((dev->regs[0x1d] << 8) | (dev->regs[0x1c] & 0xfc)) + 2;
+        } else {
+            main = 0x170;
+            side = 0x376;
+        }

-    if (dev->single_channel)
-        return;
+        ide_set_base(1, main);
+        ide_set_side(1, side);

-    ide_sec_disable();
-
-    if ((dev->regs[0x09] & 0x04) && (dev->regs[0x50] & 0x40)) {
-        main = (dev->regs[0x19] << 8) | (dev->regs[0x18] & 0xf8);
-        side = ((dev->regs[0x1d] << 8) | (dev->regs[0x1c] & 0xfc)) + 2;
-    } else {
-        main = 0x170;
-        side = 0x376;
+        if ((dev->regs[0x04] & 0x01) && (dev->regs[0x51] & 0x08))
+            ide_sec_enable();
    }
-
-    ide_set_base(1, main);
-    ide_set_side(1, side);
-
-    if ((dev->regs[0x04] & 0x01) && (dev->regs[0x51] & 0x08))
-        ide_sec_enable();
 }

 static void
@@ -368,22 +373,49 @@ cmd640_reset(void *priv)
 {
    cmd640_t *dev = (cmd640_t *) priv;
    int       i   = 0;
+    int       min_channel;
+    int       max_channel;
+
+    switch (dev->channels) {
+        default:
+        case 0x00:
+            min_channel = max_channel = 0;
+            break;
+        case 0x01:
+            min_channel = 0;
+            max_channel = 1;
+            break;
+        case 0x02:
+            min_channel = 2;
+            max_channel = 3;
+            break;
+        case 0x03:
+            min_channel = 0;
+            max_channel = 3;
+            break;
+    }

    for (i = 0; i < CDROM_NUM; i++) {
-        if ((cdrom[i].bus_type == CDROM_BUS_ATAPI) && (cdrom[i].ide_channel < 4) && cdrom[i].priv)
+        if ((cdrom[i].bus_type == CDROM_BUS_ATAPI) && (cdrom[i].ide_channel >= min_channel) &&
+            (cdrom[i].ide_channel <= max_channel) && cdrom[i].priv)
            scsi_cdrom_reset((scsi_common_t *) cdrom[i].priv);
    }
    for (i = 0; i < ZIP_NUM; i++) {
-        if ((zip_drives[i].bus_type == ZIP_BUS_ATAPI) && (zip_drives[i].ide_channel < 4) && zip_drives[i].priv)
+        if ((zip_drives[i].bus_type == ZIP_BUS_ATAPI) && (zip_drives[i].ide_channel >= min_channel) &&
+            (zip_drives[i].ide_channel <= max_channel) && zip_drives[i].priv)
            zip_reset((scsi_common_t *) zip_drives[i].priv);
    }
    for (i = 0; i < MO_NUM; i++) {
-        if ((mo_drives[i].bus_type == MO_BUS_ATAPI) && (mo_drives[i].ide_channel < 4) && mo_drives[i].priv)
+        if ((mo_drives[i].bus_type == MO_BUS_ATAPI) && (mo_drives[i].ide_channel >= min_channel) &&
+            (mo_drives[i].ide_channel <= max_channel) && mo_drives[i].priv)
            mo_reset((scsi_common_t *) mo_drives[i].priv);
    }

-    cmd640_set_irq(0x00, priv);
-    cmd640_set_irq(0x01, priv);
+    if (dev->channels & 0x01)
+        cmd640_set_irq(0x00, priv);
+
+    if (dev->channels & 0x02)
+        cmd640_set_irq(0x01, priv);

    memset(dev->regs, 0x00, sizeof(dev->regs));

@@ -429,6 +461,8 @@ cmd640_reset(void *priv)
        dev->irq_pin                        = PCI_INTA;
        dev->irq_line                       = 14;
    } else {
+        dev->regs[0x04] = 0x01;       /* To make sure the two channels get enabled. */
+
        if ((dev->local & 0xffff) == 0x0078)
            dev->regs[0x50] |= 0x20; /* 0 = 178h, 17Ch; 1 = 078h, 07Ch */

@@ -461,18 +495,26 @@ cmd640_init(const device_t *info)
    dev->pci   = !!(info->flags & DEVICE_PCI);
    dev->local = info->local;

+    dev->channels = ((info->local & 0x60000) >> 17) & 0x03;
+
    if (info->flags & DEVICE_PCI) {
        device_add(&ide_pci_2ch_device);

        dev->slot = pci_add_card(PCI_ADD_IDE, cmd640_pci_read, cmd640_pci_write, dev);

-        ide_set_bus_master(0, NULL, cmd640_set_irq, dev);
-        ide_set_bus_master(1, NULL, cmd640_set_irq, dev);
+        if (dev->channels & 0x01)
+            ide_set_bus_master(0, NULL, cmd640_set_irq, dev);
+
+        if (dev->channels & 0x02)
+            ide_set_bus_master(1, NULL, cmd640_set_irq, dev);

        /* The CMD PCI-0640B IDE controller has no DMA capability,
           so set our devices IDE devices to force ATA-3 (no DMA). */
-        ide_board_set_force_ata3(0, 1);
-        ide_board_set_force_ata3(1, 1);
+        if (dev->channels & 0x01)
+            ide_board_set_force_ata3(0, 1);
+
+        if (dev->channels & 0x02)
+            ide_board_set_force_ata3(1, 1);

 #if 0
        ide_pri_disable();
@@ -486,8 +528,6 @@ cmd640_init(const device_t *info)
                      dev);
    }

-    dev->single_channel = !!(info->local & 0x20000);
-
    next_id++;

    cmd640_reset(dev);
@@ -499,7 +539,7 @@ const device_t ide_cmd640_vlb_device = {
    .name          = "CMD PCI-0640B VLB",
    .internal_name = "ide_cmd640_vlb",
    .flags         = DEVICE_VLB,
-    .local         = 0x0078,
+    .local         = 0x60078,
    .init          = cmd640_init,
    .close         = cmd640_close,
    .reset         = cmd640_reset,
@@ -513,7 +553,63 @@ const device_t ide_cmd640_vlb_178_device = {
    .name          = "CMD PCI-0640B VLB (Port 178h)",
    .internal_name = "ide_cmd640_vlb_178",
    .flags         = DEVICE_VLB,
-    .local         = 0x0178,
+    .local         = 0x60178,
+    .init          = cmd640_init,
+    .close         = cmd640_close,
+    .reset         = cmd640_reset,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
+
+const device_t ide_cmd640_vlb_pri_device = {
+    .name          = "CMD PCI-0640B VLB",
+    .internal_name = "ide_cmd640_vlb",
+    .flags         = DEVICE_VLB,
+    .local         = 0x20078,
+    .init          = cmd640_init,
+    .close         = cmd640_close,
+    .reset         = cmd640_reset,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
+
+const device_t ide_cmd640_vlb_pri_178_device = {
+    .name          = "CMD PCI-0640B VLB (Port 178h)",
+    .internal_name = "ide_cmd640_vlb_178",
+    .flags         = DEVICE_VLB,
+    .local         = 0x20178,
+    .init          = cmd640_init,
+    .close         = cmd640_close,
+    .reset         = cmd640_reset,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
+
+const device_t ide_cmd640_vlb_sec_device = {
+    .name          = "CMD PCI-0640B VLB",
+    .internal_name = "ide_cmd640_vlb",
+    .flags         = DEVICE_VLB,
+    .local         = 0x40078,
+    .init          = cmd640_init,
+    .close         = cmd640_close,
+    .reset         = cmd640_reset,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
+
+const device_t ide_cmd640_vlb_sec_178_device = {
+    .name          = "CMD PCI-0640B VLB (Port 178h)",
+    .internal_name = "ide_cmd640_vlb_178",
+    .flags         = DEVICE_VLB,
+    .local         = 0x40178,
    .init          = cmd640_init,
    .close         = cmd640_close,
    .reset         = cmd640_reset,
@@ -527,7 +623,7 @@ const device_t ide_cmd640_pci_device = {
    .name          = "CMD PCI-0640B PCI",
    .internal_name = "ide_cmd640_pci",
    .flags         = DEVICE_PCI,
-    .local         = 0x0a,
+    .local         = 0x6000a,
    .init          = cmd640_init,
    .close         = cmd640_close,
    .reset         = cmd640_reset,
@@ -541,7 +637,7 @@ const device_t ide_cmd640_pci_legacy_only_device = {
    .name          = "CMD PCI-0640B PCI (Legacy Mode Only)",
    .internal_name = "ide_cmd640_pci_legacy_only",
    .flags         = DEVICE_PCI,
-    .local         = 0x00,
+    .local         = 0x60000,
    .init          = cmd640_init,
    .close         = cmd640_close,
    .reset         = cmd640_reset,
@@ -564,3 +660,17 @@ const device_t ide_cmd640_pci_single_channel_device = {
    .force_redraw  = NULL,
    .config        = NULL
 };
+
+const device_t ide_cmd640_pci_single_channel_sec_device = {
+    .name          = "CMD PCI-0640B PCI",
+    .internal_name = "ide_cmd640_pci_single_channel_sec",
+    .flags         = DEVICE_PCI,
+    .local         = 0x4000a,
+    .init          = cmd640_init,
+    .close         = cmd640_close,
+    .reset         = cmd640_reset,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
--- a/src/disk/hdc_ide_cmd646.c
+++ b/src/disk/hdc_ide_cmd646.c
@@ -90,7 +90,7 @@ cmd646_set_irq(int channel, void *priv)
 static int
 cmd646_bus_master_dma(int channel, uint8_t *data, int transfer_length, int out, void *priv)
 {
-    cmd646_t *dev = (cmd646_t *) priv;
+    const cmd646_t *dev = (cmd646_t *) priv;

    return sff_bus_master_dma(channel, data, transfer_length, out, dev->bm[channel & 0x01]);
 }
--- a/src/disk/hdc_ide_opti611.c
+++ b/src/disk/hdc_ide_opti611.c
@@ -31,6 +31,7 @@
 #include <86box/plat_unused.h>

 typedef struct opti611_t {
+    uint8_t is_sec;
    uint8_t tries;
    uint8_t in_cfg;
    uint8_t cfg_locked;
@@ -92,8 +93,8 @@ opti611_cfg_writel(uint16_t addr, uint32_t val, void *priv)
 static uint8_t
 opti611_cfg_read(uint16_t addr, void *priv)
 {
-    uint8_t    ret = 0xff;
-    opti611_t *dev = (opti611_t *) priv;
+    uint8_t          ret = 0xff;
+    const opti611_t *dev = (opti611_t *) priv;

    addr &= 0x0007;

@@ -254,28 +255,54 @@ opti611_ide_readl(uint16_t addr, void *priv)
 static void
 opti611_ide_handler(opti611_t *dev)
 {
-    ide_pri_disable();
-    io_removehandler(0x01f0, 0x0007,
-                     opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
-                     opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
-                     dev);
-    io_removehandler(0x01f0, 0x0007,
-                     opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
-                     opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
-                     dev);
+    if (dev->is_sec) {
+        ide_sec_disable();
+        io_removehandler(0x0170, 0x0007,
+                         opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
+                         opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
+                         dev);
+        io_removehandler(0x0170, 0x0007,
+                         opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
+                         opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
+                         dev);

-    if (dev->in_cfg && !dev->cfg_locked) {
-        io_sethandler(0x01f0, 0x0007,
-                      opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
-                      opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
-                      dev);
+        if (dev->in_cfg && !dev->cfg_locked) {
+            io_sethandler(0x0170, 0x0007,
+                          opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
+                          opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
+                          dev);
+        } else {
+            if (dev->regs[0x03] & 0x01)
+                ide_sec_enable();
+            io_sethandler(0x0170, 0x0007,
+                          opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
+                          opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
+                          dev);
+        }
    } else {
-        if (dev->regs[0x03] & 0x01)
-            ide_pri_enable();
-        io_sethandler(0x01f0, 0x0007,
-                      opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
-                      opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
-                      dev);
+        ide_pri_disable();
+        io_removehandler(0x01f0, 0x0007,
+                         opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
+                         opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
+                         dev);
+        io_removehandler(0x01f0, 0x0007,
+                         opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
+                         opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
+                         dev);
+
+        if (dev->in_cfg && !dev->cfg_locked) {
+            io_sethandler(0x01f0, 0x0007,
+                          opti611_cfg_read, opti611_cfg_readw, opti611_cfg_readl,
+                          opti611_cfg_write, opti611_cfg_writew, opti611_cfg_writel,
+                          dev);
+        } else {
+            if (dev->regs[0x03] & 0x01)
+                ide_pri_enable();
+            io_sethandler(0x01f0, 0x0007,
+                          opti611_ide_read, opti611_ide_readw, opti611_ide_readl,
+                          opti611_ide_write, opti611_ide_writew, opti611_ide_writel,
+                          dev);
+        }
    }
 }

@@ -293,6 +320,8 @@ opti611_init(UNUSED(const device_t *info))
    opti611_t *dev = (opti611_t *) malloc(sizeof(opti611_t));
    memset(dev, 0, sizeof(opti611_t));

+    dev->is_sec = info->local;
+
    dev->regs[0x12] = 0x80;
    dev->regs[0x03] = 0x01;
    dev->regs[0x05] = 0x20;
@@ -317,3 +346,17 @@ const device_t ide_opti611_vlb_device = {
    .force_redraw  = NULL,
    .config        = NULL
 };
+
+const device_t ide_opti611_vlb_sec_device = {
+    .name          = "OPTi 82C611/82C611A VLB (Secondary)",
+    .internal_name = "ide_opti611_vlb",
+    .flags         = DEVICE_VLB,
+    .local         = 1,
+    .init          = opti611_init,
+    .close         = opti611_close,
+    .reset         = NULL,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
--- a/src/disk/hdc_ide_sff8038i.c
+++ b/src/disk/hdc_ide_sff8038i.c
@@ -222,7 +222,7 @@ sff_bus_master_writel(uint16_t port, uint32_t val, void *priv)
 uint8_t
 sff_bus_master_read(uint16_t port, void *priv)
 {
-    sff8038i_t *dev = (sff8038i_t *) priv;
+    const sff8038i_t *dev = (sff8038i_t *) priv;

    uint8_t ret = 0xff;

@@ -261,7 +261,7 @@ sff_bus_master_read(uint16_t port, void *priv)
 static uint16_t
 sff_bus_master_readw(uint16_t port, void *priv)
 {
-    sff8038i_t *dev = (sff8038i_t *) priv;
+    const sff8038i_t *dev = (sff8038i_t *) priv;

    uint16_t ret = 0xffff;

@@ -290,7 +290,7 @@ sff_bus_master_readw(uint16_t port, void *priv)
 static uint32_t
 sff_bus_master_readl(uint16_t port, void *priv)
 {
-    sff8038i_t *dev = (sff8038i_t *) priv;
+    const sff8038i_t *dev = (sff8038i_t *) priv;

    uint32_t ret = 0xffffffff;

--- a/src/disk/hdc_st506_at.c
+++ b/src/disk/hdc_st506_at.c
@@ -171,7 +171,7 @@ irq_update(mfm_t *mfm)
 static int
 get_sector(mfm_t *mfm, off64_t *addr)
 {
-    drive_t *drive = &mfm->drives[mfm->drvsel];
+    const drive_t *drive = &mfm->drives[mfm->drvsel];

    /* FIXME: See if this is even needed - if the code is present, IBM AT
              diagnostics v2.07 will error with: ERROR 152 - SYSTEM BOARD. */
@@ -734,7 +734,7 @@ mfm_close(void *priv)
    mfm_t *mfm = (mfm_t *) priv;

    for (uint8_t d = 0; d < 2; d++) {
-        drive_t *drive = &mfm->drives[d];
+        const drive_t *drive = &mfm->drives[d];

        hdd_image_close(drive->hdd_num);
    }
--- a/src/disk/hdc_st506_xt.c
+++ b/src/disk/hdc_st506_xt.c
@@ -623,6 +623,10 @@ st506_callback(void *priv)
                st506_complete(dev);
                break;
            }
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
+
        case CMD_FORMAT_TRACK:
        case CMD_FORMAT_BAD_TRACK:
            switch (dev->state) {
@@ -1377,10 +1381,10 @@ mem_write(uint32_t addr, uint8_t val, void *priv)
 static uint8_t
 mem_read(uint32_t addr, void *priv)
 {
-    hdc_t   *dev = (hdc_t *) priv;
-    uint32_t ptr;
-    uint32_t mask = 0;
-    uint8_t  ret = 0xff;
+    const hdc_t *dev = (hdc_t *) priv;
+    uint32_t     ptr;
+    uint32_t     mask = 0;
+    uint8_t      ret = 0xff;

    /* Ignore accesses to anything below the configured address,
       needed because of the emulator's 4k mapping granularity. */
@@ -1529,8 +1533,8 @@ loadhd(hdc_t *dev, int c, int d, UNUSED(const char *fn))
 static void
 set_switches(hdc_t *dev, hd_type_t *hdt, int num)
 {
-    drive_t *drive;
-    int      e;
+    const drive_t *drive;
+    int            e;

    dev->switches = 0x00;

@@ -1604,7 +1608,9 @@ st506_init(const device_t *info)

        case ST506_XT_TYPE_ST11R: /* Seagate ST-11R (RLL) */
            dev->spt = RLL_SECTORS;
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif

        case ST506_XT_TYPE_ST11M: /* Seagate ST-11M (MFM) */
            dev->nr_err   = ERR_NOT_AVAILABLE;
@@ -1778,8 +1784,8 @@ st506_init(const device_t *info)
 static void
 st506_close(void *priv)
 {
-    hdc_t   *dev = (hdc_t *) priv;
-    drive_t *drive;
+    hdc_t         *dev = (hdc_t *) priv;
+    const drive_t *drive;

    for (uint8_t d = 0; d < MFM_NUM; d++) {
        drive = &dev->drives[d];
--- a/src/disk/hdc_xta.c
+++ b/src/disk/hdc_xta.c
@@ -509,7 +509,9 @@ hdc_callback(void *priv)

        case CMD_READ_VERIFY:
            no_data = 1;
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif

        case CMD_READ_SECTORS:
            if (!drive->present) {
@@ -534,7 +536,9 @@ hdc_callback(void *priv)
                    dev->buf_len = 512;

                    dev->state = STATE_SEND;
-                    /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                case STATE_SEND:
                    /* Activate the status icon. */
@@ -642,7 +646,9 @@ do_send:
                    dev->buf_len = 512;

                    dev->state = STATE_RECV;
-                    /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+                    [[fallthrough]];
+#endif

                case STATE_RECV:
                    /* Activate the status icon. */
@@ -1098,8 +1104,8 @@ xta_init(const device_t *info)
 static void
 xta_close(void *priv)
 {
-    hdc_t   *dev = (hdc_t *) priv;
-    drive_t *drive;
+    hdc_t         *dev = (hdc_t *) priv;
+    const drive_t *drive;

    /* Remove the I/O handler. */
    io_removehandler(dev->base, 4,
--- a/src/disk/hdd.c
+++ b/src/disk/hdd.c
@@ -160,7 +160,7 @@ hdd_seek_get_time(hard_disk_t *hdd, uint32_t dst_addr, uint8_t operation, uint8_
    if (!hdd->speed_preset)
        return HDD_OVERHEAD_TIME;

-    hdd_zone_t *zone = NULL;
+    const hdd_zone_t *zone = NULL;
    if (hdd->num_zones <= 0) {
        fatal("hdd_seek_get_time(): hdd->num_zones < 0)\n");
        return 0.0;
@@ -486,7 +486,7 @@ hdd_preset_apply(int hdd_id)
    if (hd->speed_preset >= hdd_preset_get_num())
        hd->speed_preset = 0;

-    hdd_preset_t *preset = &hdd_speed_presets[hd->speed_preset];
+    const hdd_preset_t *preset = &hdd_speed_presets[hd->speed_preset];

    hd->cache.num_segments = preset->rcache_num_seg;
    hd->cache.segment_size = preset->rcache_seg_size;
--- a/src/disk/hdd_image.c
+++ b/src/disk/hdd_image.c
@@ -450,7 +450,7 @@ retry_vhd:
                else
                    fatal("hdd_image_load(): VHD: Error opening VHD file '%s': %s\n", fn, mvhd_strerr(vhd_error));
            } else if (vhd_error == MVHD_ERR_TIMESTAMP) {
-                fatal("hdd_image_load(): VHD: Parent/child timestamp mismatch for VHD file '%s'\n", fn);
+                pclog("hdd_image_load(): VHD: Parent/child timestamp mismatch for VHD file '%s'\n", fn);
            }

            hdd[id].tracks        = hdd_images[id].vhd->footer.geom.cyl;
--- a/src/disk/mo.c
+++ b/src/disk/mo.c
@@ -655,7 +655,9 @@ mo_update_request_length(mo_t *dev, int len, int block_len)
                    break;
                }
            }
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        default:
            dev->packet_len = len;
            break;
@@ -1342,7 +1344,9 @@ mo_command(scsi_common_t *sc, uint8_t *cdb)
                mo_invalid_field(dev);
                return;
            }
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case GPCMD_SCSI_RESERVE:
        case GPCMD_SCSI_RELEASE:
        case GPCMD_TEST_UNIT_READY:
@@ -2051,7 +2055,7 @@ mo_do_identify(ide_t *ide, int ide_has_dma)
 {
    char model[40];

-    mo_t *mo = (mo_t *) ide->sc;
+    const mo_t *mo = (mo_t *) ide->sc;

    memset(model, 0, 40);

--- a/src/disk/zip.c
+++ b/src/disk/zip.c
@@ -821,7 +821,10 @@ zip_update_request_length(zip_t *dev, int len, int block_len)
                    break;
                }
            }
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
+
        default:
            dev->packet_len = len;
            break;
@@ -1408,7 +1411,9 @@ zip_command(scsi_common_t *sc, uint8_t *cdb)
                zip_invalid_field(dev);
                return;
            }
-            /*FALLTHROUGH*/
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case GPCMD_SCSI_RESERVE:
        case GPCMD_SCSI_RELEASE:
        case GPCMD_TEST_UNIT_READY:
@@ -1571,6 +1576,9 @@ zip_command(scsi_common_t *sc, uint8_t *cdb)
                zip_command_complete(dev);
                break;
            }
+#ifdef FALLTHROUGH_ANNOTATION
+            [[fallthrough]];
+#endif
        case GPCMD_WRITE_6:
        case GPCMD_WRITE_10:
        case GPCMD_WRITE_AND_VERIFY_10:
@@ -2280,7 +2288,7 @@ zip_250_identify(ide_t *ide, int ide_has_dma)
 static void
 zip_identify(ide_t *ide, int ide_has_dma)
 {
-    zip_t *zip;
+    const zip_t *zip;

    zip = (zip_t *) ide->sc;

--- a/src/dma.c
+++ b/src/dma.c
@@ -118,7 +118,7 @@ dma_sg_next_addr(dma_t *dev)
    dev->eot = dev->count >> 31;
    dev->count &= 0xfffe;
    dev->cb = (uint16_t) dev->count;
-    dev->cc = (int) dev->count;
+    dev->cc = dev->count;
    if (!dev->count)
        dev->count = 65536;
    if (ts == 2)
@@ -133,9 +133,7 @@ dma_sg_next_addr(dma_t *dev)
 static void
 dma_block_transfer(int channel)
 {
-    int bit16;
-
-    bit16 = (channel >= 4);
+    int bit16 = (channel >= 4);

    if (dma_advanced)
        bit16 = !!(dma_transfer_size(&(dma[channel])) == 2);
@@ -300,7 +298,7 @@ dma_sg_writel(uint16_t port, uint32_t val, void *priv)
 static uint8_t
 dma_sg_read(uint16_t port, void *priv)
 {
-    dma_t *dev = (dma_t *) priv;
+    const dma_t *dev = (dma_t *) priv;

    uint8_t ret = 0xff;

@@ -348,7 +346,7 @@ dma_sg_read(uint16_t port, void *priv)
 static uint16_t
 dma_sg_readw(uint16_t port, void *priv)
 {
-    dma_t *dev = (dma_t *) priv;
+    const dma_t *dev = (dma_t *) priv;

    uint16_t ret = 0xffff;

@@ -382,7 +380,7 @@ dma_sg_readw(uint16_t port, void *priv)
 static uint32_t
 dma_sg_readl(uint16_t port, void *priv)
 {
-    dma_t *dev = (dma_t *) priv;
+    const dma_t *dev = (dma_t *) priv;

    uint32_t ret = 0xffffffff;

@@ -596,7 +594,7 @@ dma_write(uint16_t addr, uint8_t val, UNUSED(void *priv))
 static uint8_t
 dma_ps2_read(uint16_t addr, UNUSED(void *priv))
 {
-    dma_t  *dma_c = &dma[dma_ps2.xfr_channel];
+    const dma_t  *dma_c = &dma[dma_ps2.xfr_channel];
    uint8_t temp  = 0xff;

    switch (addr) {
@@ -1280,7 +1278,7 @@ dma_sg(uint8_t *data, int transfer_length, int out, void *priv)
 uint8_t
 _dma_read(uint32_t addr, dma_t *dma_c)
 {
-    uint8_t temp;
+    uint8_t temp = 0;

    if (dma_advanced) {
        if (dma_c->sg_status & 1)
@@ -1296,7 +1294,7 @@ _dma_read(uint32_t addr, dma_t *dma_c)
 static uint16_t
 _dma_readw(uint32_t addr, dma_t *dma_c)
 {
-    uint16_t temp;
+    uint16_t temp = 0;

    if (dma_advanced) {
        if (dma_c->sg_status & 1)
--- a/src/fifo8.c
+++ b/src/fifo8.c
@@ -84,7 +84,7 @@ fifo8_pop(Fifo8 *fifo)
 const uint8_t *
 fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num)
 {
-    uint8_t *ret;
+    const uint8_t *ret;

    assert(max > 0 && max <= fifo->num);
    *num = MIN(fifo->capacity - fifo->head, max);
--- a/Show More
+++ b/Show More