[PATCH v2 1/3] doc: usage: Add general rule for `$?`

[Quentin Schulz]

Hi Tom,

On 10/24/25 6:02 PM, Tom Rini wrote:
> For nearly all commands in U-Boot the '?' variable is handled the same
> way with 0 meaning success, 1 meaning any failure.  Explain this in the
> general rules section of the cmdline documentation (with a link to a
> counter example) and then remove the redundant wording from most
> commands. We retain a section about the return value in a number of
> places where we are doing something such as always returning a specific
> value or we have useful additional information to go along with the
> normal return codes.
> 
> Signed-off-by: Tom Rini <trini at konsulko.com>
> ---
> Changes in v2:
> - Rewordings suggested by Quentin
> - After confirming that invalid syntax also always returns 1 and not -1,

For example cmd/scmi.c do_scmi_set_proto() can return CMD_RET_USAGE 
which is a -1 enum and the function returns an int, so I assume this 
would be propagated properly?

I don't have time today to check the cmd function call stack to see if 
it is, but this seems odd to me.

Cheers,
Quentin