ARM: rpi_b: detect board revision
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.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
3 files changed