TF-A v2.6 now supports DFU for USB bootstrap on the STM32MP1. This is normally exercised by the STM32CubeProgrammer, but is easily usable with just dfu-util as well. Document how to. Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- Documentation/boards/stm32mp.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/Documentation/boards/stm32mp.rst b/Documentation/boards/stm32mp.rst index 0c9615b290a5..4cdd281a9e14 100644 --- a/Documentation/boards/stm32mp.rst +++ b/Documentation/boards/stm32mp.rst @@ -49,6 +49,8 @@ In the above output, images with a ``.stm32`` extension feature the (legacy) stm32image header. ``barebox-dt-2nd.img`` and ``barebox-stm32mp-generic-bl33.img`` are board-generic barebox images that receive an external device tree. +.. _stm32mp_fip: + Flashing barebox (FIP) ---------------------- @@ -137,6 +139,34 @@ Assuming ``CONFIG_CMD_MMC_EXTCSD`` is enabled and the board shall boot from The STM32MP1 BootROM does *not* support booting from eMMC without fast boot acknowledge. +USB Bootstrap (DFU) +------------------- + +The STM32MP1 can be strapped to boot from USB. After Power-On reset, it +should be detectable as ``STMicroelectronics STM Device in DFU Mode`` +and can be uploaded to with ``dfu-util(1)``:: + + dfu-util --alt 1 -D tf-a-stm32mp157c-my-board.stm32 + dfu-util --alt 3 -D bl3-firmware.fip + dfu-util --alt 0 -e + +The first command will talk to the BootROM and upload the first stage +bootloader (ARM Trusted Firmware-A) into on-chip SRAM. + +When compiled with ``STM32MP_USB_PROGRAMMER=1``, TF-A v2.6 or higher +will seamlessly continue operation of the DFU gadget. The second +command will talk to TF-A to upload a Firmware Image Package, which +is a format bundling further firmware including barebox. + +The final command will instruct TF-A to boot the loaded images. +This all happens in volatile memory. To persist images, use +normal barebox functionality like creating a DFU-gadget in barebox, +Fastboot/USB mass storage ... etc. + +The FIP image containing barebox can be generated as described in +137::ref:`stm32mp_fip`. Upstream TF-A doesn't support DFU for +SSBLs using the legacy stm32image format. + Boot source selection --------------------- -- 2.30.2 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
