# System

[中文]

## 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-S2/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-S2/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 necessary, 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-S2/` (new include path: `ESP32-S2/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 supported by default. Users should do one of the following:

- 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_ESP32S2_REV_MIN and `<` `CONFIG_ESP32S2_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_ESP32S2_REV_MIN and `<` `CONFIG_ESP32S2_REV_MAX_FULL`.

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