tree 9a4c733db8ec3b99444a5ff9177aeb709459ad07
parent c4f5738e690487dc59c8234782e792e57dac9a22
author Sean Anderson <sean.anderson@seco.com> 1670872331 -0500
committer Tom Rini <trini@konsulko.com> 1672511719 -0500

cmd: source: Support specifying config name

As discussed previously [1,2], the source command is not safe to use with
verified boot unless there is a key with required = "images" (which has its
own problems). This is because if such a key is absent, signatures are
verified but not required. It is assumed that configuration nodes will
provide the signature. Because the source command does not use
configurations to determine the image to source, effectively no
verification takes place.

To address this, allow specifying configuration nodes. We use the same
syntax as the bootm command (helpfully provided for us by fit_parse_conf).
By default, we first try the default config and then the default image. To
force using a config, # must be present in the command (e.g. `source
$loadaddr#my-conf`). For convenience, the config may be omitted, just like
the address may be (e.g. `source \#`). This also works for images
(`source :` behaves exactly like `source` currently does).

[1] https://lore.kernel.org/u-boot/7d711133-d513-5bcb-52f2-a9dbaa9eeded@prevas.dk/
[2] https://lore.kernel.org/u-boot/042dcb34-f85f-351e-1b0e-513f89005fdd@gmail.com/

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>