System API
- App Image Format
 - Application Level Tracing
 - Call function with external stack
 - Console
 - eFuse Manager
 - Error Codes and Helper Functions
 - ESP HTTPS OTA
 - Event Loop Library
 - FreeRTOS
 - FreeRTOS Supplemental Features
 - Heap Memory Allocation
 - Heap Memory Debugging
 - High Resolution Timer (ESP Timer)
 - Internal and Unstable APIs
 - Interrupt allocation
 - Logging library
 - Miscellaneous System APIs
 - Over The Air Updates (OTA)
 - Power Management
 - POSIX Threads Support
 - Random Number Generation
 - Sleep Modes
 - SoC Capabilities
 - System Time
 - The Async memcpy API
 - Watchdogs
 
Code examples for this API section are provided in the system directory of ESP-IDF examples.