STM32 Flashing

Flashing the Board Using OpenOCD

The ST Nucleo32, 64 and 144 boards include an on-board ST-LINK programmer and can be flashed using OpenOCD (use version 0.11.0 at least). OpenOCD is the standard programmer for all Nucleo boards, so no explicit PROGRAMMER environment variable has to be set.

To flash this board, just use the following command (replace the xxxxx with your Nucleo variant):

make BOARD=nucleo-xxxxx flash -C examples/basic/hello-world

If your board does not have OpenOCD set as the default programmer, you can select it by explicitly setting the PROGRAMMER variable:

make BOARD=xxxxx PROGARMMER=openocd flash

Flashing the Board Using the ST-LINK Mass Storage Device

The on-board ST-Link programmer found on all Nucleo32, 64 and 144 boards will show up as a mass storage device when plugged in via USB. Copying a HEX file to the mass storage device will trigger the flashing sequence of the ST-Link. This can either be done manually or with the cpy2remed (copy to removable media) PROGRAMMER script. To use this programmer, you can use the following command:

make BOARD=nucleo-xxxx PROGRAMMER=cpy2remed flash

Note

If the flash operation fails for some reason, it is possible that the embedded ST-Link firmware is either too old or has bugs that have been fixed in the meantime. You can find updates for the ST-Link on this STM webpage.

Flashing the Board using stm32flash

It is possible to automatically boot the STM32 board into the in-ROM bootloader that stm32flash communicates with for flashing by connecting the RST pin to DTR and the BOOT pin (or BOOT0 for STM32 MCU families with BOOT0 and BOOT1 pins) to RTS of the TTL adapter. In addition, set STM32FLASH_RESET to 1 via environment or command line to actually issue a reset with BOOT (or BOOT0) pulled high prior flashing to enter the bootloader, and a second reset with BOOT (or BOOT0) pulled low to reboot into the application. STM32FLASH_RESET defaults to 0 as of know, as with PROGRAMMER=stm32flash STM32FLASH_RESET=1 additional terminal flags are set, so that make term doesn’t accidentally keep the reset signal pulled low or boots the board into the bootloader.

make BOARD=xxxx PROGRAMMER=stm32flash STM32FLASH_RESET=1 flash

The TTL adapter this was tested with had inverted RTS and DTR signal. By setting STM32FLASH_RESET_INVERT to 1 RIOT will assume RTS and DTR signals to be inverted, by setting it to 0 non-inverted signals will be generated. As of now, STM32FLASH_RESET_INVERT is by default 1. This may change if it becomes evident that non-inverted TTL adapters are in fact more common than inverted adapters.