How to create your board device tree

1. Article purpose

This article will help you to create a first TF-A device tree with STM32CubeMX, to bring up your board.

2. TF-A setup to get the serial log and USB boot

• In STM32CubeMX:
  • Create a new project from the MCU selector
  • Select the STM32MP1 part number that is mounted on your board
  • In Pinout & Configuration:
    • RCC: enable the HSE according to your board setup. The HSE is needed for various PLL (USB, DDR).
    • UARTx: setup the serial console.
      • Assign UARTx to the "Cortex-A7 non-secure" and the "Boot loader" contexts
      • Select the "Asynchronous" mode
      • In the pinout view, change the RX and TX lines (if STM32CubeMX default proposal is not good)

Information

UARTx instance is gotten from the device tree for the console but it is hard coded to UART4 with TX on GPIOG11 for the crash console, in plat/st/stm32mp1/stm32mp1_def.h

Trusted Firmware for Arm Cortex-A

Microcontroller Unit (MCUs have internal flash memory and are intended to operate with a minimum amount of external support ICs. They commonly are a self-contained, system-on-chip (SoC) designs.)

Reset and Clock Control

High Speed External oscillator (STM32 clock source)

Doubledata rate (memory domain)

Receive

Transmit