ST Nucleo G474RE

This is the page for a port of NuttX to the ST Micro Nucleo G474RE board with STM32G474RE MCU. For more information about this board, see:

Development Environment

Toolchains

An appropriate ARM toolchain is needed, such as the one built with the customized NuttX buildroot or the ready-made GNU Tools for Arm Embedded Processors.

Debugging

The board incorporates a STLINK-V3E programmer/debugger accessible via the Micro-USB Type B connector.

To debug with OpenOCD and arm-nuttx-eabi-gdb:

  • Use ‘make menuconfig’ to set CONFIG_DEBUG_SYMBOLS and CONFIG_DEBUG_NOOPT. To see debug output, e.g., the “ABCDE” printed in __start(), also set CONFIG_DEBUG_FEATURES.

  • Build NuttX.

  • Flash the code using:

    $ openocd -f interface/stlink.cfg -f target/stm32g4x.cfg -c init \
-c "reset halt" -c "flash write_image erase nuttx.bin 0x08000000"

  • Start GDB with:

    $ arm-nuttx-eabi-gdb -tui nuttx

  • In GDB:

    (gdb) target remote localhost:3333
(gdb) monitor reset halt
(gdb) load

Hardware

MCU Clocking

By default, the MCU on this board is clocked from the MCU’s internal HSI clock, and only this option is supported by software at this time.

If software support is added for it, the MCU could be clocked from the following other sources: a 24 MHz oscillator on X2, MCO from STLINK-V3E, or external clock from connector CN9, pin 26.

GPIOs

Buttons

The board has 1 user button.

LEDs

The board has 1 user LED.

Serial Consoles

The MCU’s USART3 is exposed to the pin 1 and 2 of the “Morpho connector” CN7 on the board.

FLASH Bootloader Support

If implementing a FLASH bootloader, turn on Kconfig option CONFIG_STM32_DFU. This option activates an alternate linker script, scripts/ld.script.dfu, which causes NuttX to leave a gap at the start of FLASH, leaving that space for the FLASH bootloader. See scripts/ld.script.dfu for details. It also causes NuttX to relocate its vector table and possibly make other adjustments.

One possible bootloader is STmicro’s OpenBootloader “middleware” supplied with STM32CubeG4 version 1.3.0. On the host (PC), it should be possible to use STmicro’s STM32CubeProgrammer or the stm32loader.py script from https://github.com/jsnyder/stm32loader. That script can be invoked with parameters such as:

stm32loader.py -p /dev/ttyACM0 -a 0x08006000 -e -w -v -g 0x08006000 nuttx.bin

where the given address (0x08006000 in this case) must match the starting address in scripts/ld.script.dfu.