System

Inter-Processor Call

IPC (Inter-Processor Call) feature is no longer a stand-alone component and has been integrated into the esp_system component.

Thus, any project presenting a CMakeLists.txt file with the parameters PRIV_REQUIRES esp_ipc or REQUIRES esp_ipc should be modified to simply remove these options as the esp_system component is included by default.

ESP Clock

The ESP Clock API (functions/types/macros prefixed with esp_clk) has been made into a private API. Thus, the previous include paths #include "ESP32-C2/clk.h" and #include "esp_clk.h" have been removed. If users still require usage of the ESP Clock API (though this is not recommended), it can be included via #include "esp_private/esp_clk.h".

Note

Private APIs are not stable and no are longer subject to the ESP-IDF versioning scheme's breaking change rules. Thus, it is not recommended for users to continue calling private APIs in their applications.

Cache Error Interrupt

The Cache Error Interrupt API (functions/types/macros prefixed with esp_cache_err) has been made into a private API. Thus, the previous include path #include "ESP32-C2/cache_err_int.h" has been removed. If users still require usage of the Cache Error Interrupt API (though this is not recommended), it can be included via #include "esp_private/cache_err_int.h".

bootloader_support

The function bootloader_common_get_reset_reason() has been removed. Please use the function esp_rom_get_reset_reason() in the ROM component.
The functions esp_secure_boot_verify_sbv2_signature_block() and esp_secure_boot_verify_rsa_signature_block() have been removed without replacement. We do not expect users to use these directly. If they are indeed still neccessary, please open a feature request on GitHub explaining why these functions are necessary to you.

Brownout

The Brownout API (functions/types/macros prefixed with esp_brownout) has been made into a private API. Thus, the previous include path #include "brownout.h" has been removed. If users still require usage of the Brownout API (though this is not recommended), it can be included via #include "esp_private/brownout.h".

Trax

The Trax API (functions/types/macros prefixed with trax_) has been made into a private API. Thus, the previous include path #include "trax.h" has been removed. If users still require usage of the Trax API (though this is not recommended), it can be included via #include "esp_private/trax.h".

ROM

The previously deprecated ROM-related header files located in components/esp32/rom/ (old include path: rom/*.h) have been moved. Please use the new target-specific path from components/esp_rom/include/ESP32-C2/ (new include path: ESP32-C2/rom/*.h).

esp_hw_support

The header files soc/cpu.h have been deleted and deprecated CPU util functions have been removed. ESP-IDF developers should include esp_cpu.h instead for equivalent functions.
The header files hal/cpu_ll.h, hal/cpu_hal.h, hal/soc_ll.h, hal/soc_hal.h and interrupt_controller_hal.h CPU API functions have been deprecated. ESP-IDF developers should include esp_cpu.h instead for equivalent functions.
The header file compare_set.h have been deleted. ESP-IDF developers should use esp_cpu_compare_and_set() function provided in esp_cpu.h instead.
esp_cpu_get_ccount(), esp_cpu_set_ccount() and esp_cpu_in_ocd_debug_mode() were removed from esp_cpu.h. ESP-IDF developers should use respectively esp_cpu_get_cycle_count(), esp_cpu_set_cycle_count() and esp_cpu_dbgr_is_attached() instead.
The header file esp_intr.h has been deleted. Please include esp_intr_alloc.h to allocate and manipulate interrupts.
The Panic API (functions/types/macros prefixed with esp_panic) has been made into a private API. Thus, the previous include path #include "esp_panic.h" has been removed. If users still require usage of the Trax API (though this is not recommended), it can be included via #include "esp_private/panic_reason.h". Besides, developers should include esp_debug_helpers.h instead to use any debug-related helper functions, e.g., print backtrace.
The header file soc_log.h is now renamed to esp_hw_log.h and has been made private. Users are encouraged to use logging APIs provided under esp_log.h instead.
The header files spinlock.h, clk_ctrl_os.h, and rtc_wdt.h must now be included without the soc prefix. For example, #include "spinlock.h".
esp_chip_info() returns the chip version in the format = 100 * major eFuse version + minor eFuse version. Thus, the revision in the esp_chip_info_t structure is expanded to uint16_t to fit the new format.

PSRAM

The target-specific header file spiram.h and the header file esp_spiram.h have been removed. A new component esp_psram is created instead. For PSRAM/SPIRAM-related functions, users now include esp_psram.h and set the esp_psram component as a component requirement in their CMakeLists.txt project files.
esp_spiram_get_chip_size and esp_spiram_get_size have been deleted. You should use esp_psram_get_size instead.

eFuse

The parameter type of function esp_secure_boot_read_key_digests() changed from ets_secure_boot_key_digests_t* to esp_secure_boot_key_digests_t*. The new type is the same as the old one, except that the allow_key_revoke flag has been removed. The latter was always set to true in current code, not providing additional information.
Added eFuse wafer revisions: major and minor. The esp_efuse_get_chip_ver() API is not compatible with these changes, so it was removed. Instead, please use the following APIs: efuse_hal_get_major_chip_version(), efuse_hal_get_minor_chip_version() or efuse_hal_chip_revision().

esp_common

EXT_RAM_ATTR is deprecated. Use the new macro EXT_RAM_BSS_ATTR to put .bss on PSRAM.

esp_system

The header files esp_random.h, esp_mac.h, and esp_chip_info.h, which were all previously indirectly included via the header file esp_system.h, must now be included directly. These indirect inclusions from esp_system.h have been removed.
The Backtrace Parser API (functions/types/macros prefixed with esp_eh_frame_) has been made into a private API. Thus, the previous include path #include "eh_frame_parser.h" has been removed. If users still require usage of the Backtrace Parser API (though this is not recommended), it can be included via #include "esp_private/eh_frame_parser.h".
The Interrupt Watchdog API (functions/types/macros prefixed with esp_int_wdt_) has been made into a private API. Thus, the previous include path #include "esp_int_wdt.h" has been removed. If users still require usage of the Interrupt Watchdog API (though this is not recommended), it can be included via #include "esp_private/esp_int_wdt.h".

SOC Dependency

Public API headers listed in the Doxyfiles will not expose unstable and unnecessary soc header files, such as soc/soc.h and soc/rtc.h. That means the user has to explicitly include them in their code if these "missing" header files are still wanted.
Kconfig option LEGACY_INCLUDE_COMMON_HEADERS is also removed.
The header file soc/soc_memory_types.h has been deprecated. Users should use the esp_memory_utils.h instead. Including soc/soc_memory_types.h will bring a build warning like soc_memory_types.h is deprecated, please migrate to esp_memory_utils.h

APP Trace

One of the timestamp sources has changed from the legacy timer group driver to the new GPTimer. Kconfig choices like APPTRACE_SV_TS_SOURCE_TIMER00 has been changed to APPTRACE_SV_TS_SOURCE_GPTIMER. User no longer need to choose the group and timer ID.

esp_timer

The FRC2-based legacy implementation of esp_timer available on ESP32 has been removed. The simpler and more efficient implementation based on the LAC timer is now the only option.

ESP Image

The image SPI speed enum definitions have been renamed.

Enum ESP_IMAGE_SPI_SPEED_80M has been renamed to ESP_IMAGE_SPI_SPEED_DIV_1.
Enum ESP_IMAGE_SPI_SPEED_40M has been renamed to ESP_IMAGE_SPI_SPEED_DIV_2.
Enum ESP_IMAGE_SPI_SPEED_26M has been renamed to ESP_IMAGE_SPI_SPEED_DIV_3.
Enum ESP_IMAGE_SPI_SPEED_20M has been renamed to ESP_IMAGE_SPI_SPEED_DIV_4.

Task Watchdog Timers

The API for esp_task_wdt_init() has changed as follows:
- Configuration is now passed as a configuration structure.
- The function will now handle subscribing of the idle tasks if configured to do so.
The former CONFIG_ESP_TASK_WDT configuration option has been renamed to CONFIG_ESP_TASK_WDT_INIT and a new CONFIG_ESP_TASK_WDT_EN option has been introduced.

FreeRTOS

Legacy API and Data Types

Previously, the configENABLE_BACKWARD_COMPATIBILITY option was set by default, thus allowing pre FreeRTOS v8.0.0 function names and data types to be used. The configENABLE_BACKWARD_COMPATIBILITY is now disabled by default, thus legacy FreeRTOS names/types are no longer supportd by default. Users should do one of the followings:

Update their code to remove usage of legacy FreeRTOS names/types.
Enable the CONFIG_FREERTOS_ENABLE_BACKWARD_COMPATIBILITY to explicitly allow the usage of legacy names/types.

Tasks Snapshot

The header task_snapshot.h has been removed from freertos/task.h. ESP-IDF developers should include freertos/task_snapshot.h if they need tasks snapshot API.

The function vTaskGetSnapshot() now returns BaseType_t. Return value shall be pdTRUE on success and pdFALSE otherwise.

FreeRTOS Asserts

Previously, FreeRTOS asserts were configured separately from the rest of the system using the FREERTOS_ASSERT kconfig option. This option has now been removed and the configuration is now done through COMPILER_OPTIMIZATION_ASSERTION_LEVEL.

Port Macro API

The file portmacro_deprecated.h which was added to maintain backward compatibility for deprecated APIs is removed. Users are advised to use the alternate functions for the deprecated APIs as listed below:

portENTER_CRITICAL_NESTED() is removed. Users should use the portSET_INTERRUPT_MASK_FROM_ISR() macro instead.
portEXIT_CRITICAL_NESTED() is removed. Users should use the portCLEAR_INTERRUPT_MASK_FROM_ISR() macro instead.
vPortCPUInitializeMutex() is removed. Users should use the spinlock_initialize() function instead.
vPortCPUAcquireMutex() is removed. Users should use the spinlock_acquire() function instead.
vPortCPUAcquireMutexTimeout() is removed. Users should use the spinlock_acquire() function instead.
vPortCPUReleaseMutex() is removed. Users should use the spinlock_release() function instead.

App Update

The functions esp_ota_get_app_description() and esp_ota_get_app_elf_sha256() have been termed as deprecated. Please use the alternative functions esp_app_get_description() and esp_app_get_elf_sha256() respectively. These functions have now been moved to a new component esp_app_format. Please refer to the header file esp_app_desc.h .

Bootloader Support

The esp_app_desc_t structure, which used to be declared in esp_app_format.h , is now declared in esp_app_desc.h .
The function bootloader_common_get_partition_description() has now been made private. Please use the alternative function esp_ota_get_partition_description(). Note that this function takes esp_partition_t as its first argument instead of esp_partition_pos_t.

Chip Revision

The bootloader checks the chip revision at the beginning of the application loading. The application can only be loaded if the version is >= CONFIG_ESP32C2_REV_MIN and < CONFIG_ESP32C2_REV_MAX_FULL.

During the OTA upgrade, the version requirements and chip revision in the application header are checked for compatibility. The application can only be updated if the version is >= CONFIG_ESP32C2_REV_MIN and < CONFIG_ESP32C2_REV_MAX_FULL.

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