[PATCH] Documentation: i.MX8M: add EVK barebox installation documentation

[Sascha Hauer]

On Tue, Jan 03, 2023 at 10:54:48PM +0100, Ahmad Fatoum wrote:
> The barebox i.MX images have a preamble that pads the i.MX header to the
> offset expected by the BootROM. This allows writing barebox images
> directly to offset 0 on SD-Cards and eMMC user area. For some i.MX8M,
> these images can't be directly written to eMMC boot partitions and
> instead require special handling. Add a note about this to the
> documentation.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  Documentation/boards/imx/nxp-imx8mm-evk.rst | 18 ++++++++++++++++
>  Documentation/boards/imx/nxp-imx8mn-evk.rst | 24 +++++++++++++++++++++
>  Documentation/boards/imx/nxp-imx8mp-evk.rst | 24 +++++++++++++++++++++
>  3 files changed, 66 insertions(+)
> 
> diff --git a/Documentation/boards/imx/nxp-imx8mm-evk.rst b/Documentation/boards/imx/nxp-imx8mm-evk.rst
> index c3cd35ae38a2..7ed7459c08a6 100644
> --- a/Documentation/boards/imx/nxp-imx8mm-evk.rst
> +++ b/Documentation/boards/imx/nxp-imx8mm-evk.rst
> @@ -69,3 +69,21 @@ board for serial download mode as printed on the PCB. You can start barebox with
>  the imx-usb-loader tool that comes with barebox like this:
>  
>  ./scripts/imx/imx-usb-loader images/barebox-nxp-imx8mm-evk.img
> +
> +Installing barebox
> +==================
> +
> +When the EVK is strapped to boot from eMMC, the i.MX8M bootrom will
> +consult the eMMC ext_csd register to determine whether to boot
> +from the active eMMC boot partition or from the user area.
> +
> +The same barebox image written to the start of the SD-Card can
> +be written to the start of the eMMC user area. Power-fail installation
> +to the eMMC boot partition requires special handling:

"Power-fail installation" sounds strange. What you mean is an
installation into the boot partitions which can be updated power fail
safely.

I don't know how to put that into two words, maybe just drop the
"Power-fail" part.

Sascha


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