[PATCH v2 5/5] doc: board: document support for USB DFU boot on AM62Px SoC

[Roger Quadros]

On 18/12/2024 14:45, Siddharth Vadapalli wrote:
> Since USB DFU boot is supported on AM62Px SoC, document the steps
> required to build the image for USB DFU boot along with the steps to
> send images using the "dfu-util" tool.
> 
> Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
> ---
> This patch has been newly introduced in this series based on the
> discussion at:
> https://patchwork.ozlabs.org/project/uboot/patch/20241217131658.2920799-3-s-vadapalli@ti.com/#3432702
> 
> NOTE: This patch should only be merged if all other patches in this
> series will also be merged, in order to ensure that the feature is
> documented only if it is supported (i.e. all patches in this series
> which are required for the feature to be functional have been merged).
> 
>  doc/board/ti/am62px_sk.rst | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/doc/board/ti/am62px_sk.rst b/doc/board/ti/am62px_sk.rst
> index 99bdc034869..75451ad76b5 100644
> --- a/doc/board/ti/am62px_sk.rst
> +++ b/doc/board/ti/am62px_sk.rst
> @@ -124,6 +124,18 @@ Set the variables corresponding to this platform:
>      :start-after: .. k3_rst_include_start_build_steps_spl_r5
>      :end-before: .. k3_rst_include_end_build_steps_spl_r5
>  
> +* 3.1.1 Alternative build of R5 for DFU boot:
> +
> +  As the SPL size can exceed the limit when building it with support for
> +  booting from both local storage *and* DFU, in order to disable the
> +  configs not required for DFU boot, a config fragment should be used
> +  to not only enable configs for DFU boot, but also disabled the unneeded
> +  configs.
> +
> +.. prompt:: bash $
> +
> +   export UBOOT_CFG_CORTEXR="${UBOOT_CFG_CORTEXR} am62x_r5_usbdfu.config"
> +
>  * 3.2 A53:
>  
>  .. include::  ../ti/k3.rst
> @@ -290,6 +302,25 @@ https://www.ti.com/lit/pdf/spruj83 under the `Boot Mode Pins` section.
>  
>  For SW2 and SW1, the switch state in the "ON" position = 1.
>  
> +DFU based boot
> +--------------
> +
> +To boot the board over DFU, set the switches to DFU mode and connect to the
> +USB type C DRD port on the board. After power-on the build artifacts needs to be
> +uploaded one by one with a tool like dfu-util.
> +
> +The initial ROM will have a DFU alt named `bootloader` for the initial R5 spl
> +upload. The next stages as exposed by U-Boot have target alts matching the name
> +of the artifacts, for these a USB reset has to be done after each upload.
> +
> +When using dfu-util the following commands can be used to boot to a U-Boot shell:
> +
> +.. prompt:: bash $
> +
> +  dfu-util -a bootloader -D tiboot3.bin
> +  dfu-util -R -a tispl -D tispl.bin
> +  dfu-util -R -a u-boot.img -D u-boot.img

Is there a known reason why -R was not used for the first command but required in last two?
What about if -R is not used for all 3 commands?

> +
>  Debugging U-Boot
>  ----------------
>  

-- 
cheers,
-roger