[U-Boot] [PATCH U-Boot] ARM: rpi_b: detect board revision

[Stephen Warren]

On 11/18/2014 09:40 PM, Stephen Warren wrote:
> Detect the board revision early during boot, and print the decoded
> model name.
>
> Eventually, this information can be used for tasks such as:
> - Allowing/preventing USB device mode; some models have a USB device on-
>    board so only host mode makes sense. Others connect the SoC directly
>    to the USB connector, so device-mode might make sense.
> - The on-board USB hub/Ethernet requires different GPIOs to enable it,
>    although luckily the default appears to be fine so far.
> - The compute module contains an on-board eMMC device, so we could store
>    the environment there. Other models use an SD card and so don't support
>    saving the environment (unless we store it in a file on the FAT boot
>    partition...)
>
> Set $fdtfile based on this information. At present, the mainline Linux
> kernel doesn't contain a separate DTB for most models, but I hope that
> will change soon.

BTW, I should have mentioned that I'm hoping the kernel people CC'd here 
will take a look at the DTB filenames this patch assumes, and comment on 
whether they seem reasonable. If so, we can formulate a patch for the 
kernel to actually create all those DTs in the nearish future.