esp32s3/
Everything that knows about the chip. A program includes board.h and never touches a register directly.
- board.cboard_init() — zero .bss, disable watchdogs, raise the clock
- clock.cCPU clock: read it, switch to 160 MHz, ungate peripherals
- console.cText over USB-Serial-JTAG
- delay.cBusy-wait timing
- gpio.cDigital pins, and the GPIO matrix peripherals reach them through
- uart.cHardware serial ports
- i2c.cI2C master
- spi.cSPI master on GP-SPI2
- pwm.cPWM on the LEDC peripheral
- adc.cADC1 one-shot conversions: one call, one 12-bit reading
- watchdog.cDisable the ROM's watchdogs
- led.cAddressable RGB LED (WS2812) bit-banging driver
- linker.ldWhere the two segments land in SRAM