Espressif ESP32-S2 User Manual

Chapter 2. API Reference
App version
Application version is stored in esp_app_desc_t structure. It is located in DROM sector and has a fixed
offset from the beginning of the binary file. The structure is located after esp_image_header_t and
esp_image_segment_header_t structures. The field version has string type and max length 32 chars.
To set version in your project manually you need to set PROJECT_VER variable in your project CMake-
Lists.txt/Makefile:
• In application CMakeLists.txt put set(PROJECT_VER "0.1.0.1") before including project.
cmake.
(For legacy GNU Make build system: in application Makefile put PROJECT_VER = "0.1.0.1" before including
project.mk.)
If CONFIG_APP_PROJECT_VER_FROM_CONFIG option is set, the value of CONFIG_APP_PROJECT_VER will
be used. Otherwise if PROJECT_VER variable is not set in the project then it will be retrieved from ei-
ther $(PROJECT_PATH)/version.txt file (if present) else using git command git describe. If
neither is available then PROJECT_VER will be set to “1”. Application can make use of this by calling
esp_ota_get_app_description() or esp_ota_get_partition_description() functions.
API Reference
Header File
• components/esp_system/include/esp_system.h
Functions
esp_err_t esp_register_shutdown_handler(shutdown_handler_t handle)
Register shutdown handler.
This function allows you to register a handler that gets invoked before the application is restarted using
esp_restart function.
Return
• ESP_OK on success
• ESP_ERR_INVALID_STATE if the handler has already been registered
• ESP_ERR_NO_MEM if no more shutdown handler slots are available
Parameters
• handle: function to execute on restart
esp_err_t esp_unregister_shutdown_handler(shutdown_handler_t handle)
Unregister shutdown handler.
This function allows you to unregister a handler which was previously registered using
esp_register_shutdown_handler function.
• ESP_OK on success
• ESP_ERR_INVALID_STATE if the given handler hasn’t been registered before
void esp_restart(void)
Restart PRO and APP CPUs.
This function can be called both from PRO and APP CPUs. After successful restart, CPU reset reason will be
SW_CPU_RESET. Peripherals (except for WiFi, BT, UART0, SPI1, and legacy timers) are not reset. This
function does not return.
esp_reset_reason_t esp_reset_reason(void)
Get reason of last reset.
Return See description of esp_reset_reason_t for explanation of each value.
uint32_t esp_get_free_heap_size(void)
Get the size of available heap.
Espressif Systems 1014
Submit Document Feedback
Release v4.4

Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English