System API ********** .. toctree:: :maxdepth: 1 FreeRTOS <freertos> FreeRTOS Additions <freertos_additions> Heap Memory Allocation <mem_alloc> Heap Memory Debugging <heap_debug> Himem (large external SPI RAM) API <himem> Interrupt Allocation <intr_alloc> Watchdogs <wdts> eFuse Manager <efuse> Inter-Processor Call <ipc> High Resolution Timer <esp_timer> Logging <log> Event Loop Library <esp_event> Application Level Tracing <app_trace> Power Management <power_management> Sleep Modes <sleep_modes> Over The Air Updates (OTA) <ota> ESP HTTPS OTA <esp_https_ota> ESP pthread <esp_pthread> Error Codes and Helper Functions <esp_err> App image format <app_image_format> Miscellaneous System APIs <system> Code examples for this API section are provided in the :example:`system` directory of ESP-IDF examples.