[PATCH 1/2] Documentation: boards: stm32mp: document USB bootstrap via DFU

[Sascha Hauer]

On Fri, May 20, 2022 at 01:14:28PM +0200, Ahmad Fatoum wrote:
> 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 at pengutronix.de>
> ---
>  Documentation/boards/stm32mp.rst | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)

Applied, thanks

Sascha

> 
> 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 at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 

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