Re: [PATCH v2 2/2] cmd/part.c: implement "part name" subcommand

[Rasmus Villemoes <ravi@prevas.dk>]

On Mon, Nov 03 2025, Quentin Schulz <quentin.schulz@cherry.de> wrote:

> Hi Rasmus,
>
> On 10/20/25 2:11 PM, Rasmus Villemoes wrote:
>> This is a natural buddy to the existing "part number", allowing one to
>> get the partition name for a given partition number.
>> 
>
> Acked-by: Quentin Schuloz <quentin.schulz@cherry.de>
>

Thanks.

> 
> Reading the code, it seems the part command tries to auto-detect the
> base of the part number as passed by the user, which isn't that usual
> I believe in U-Boot (usually either forced hex or dec?), so maybe it's
> worth mentioning in the docs.

Fun story: I started doing this because I have a legacy stand-alone app
which is involved in the bootflow, and it communicates the partition to
load the kernel from by setting an env variable via

  sprintf(buf, "%d", kernel_part);
  env_set("kernel_part", buf);

and on the U-Boot side, that $kernel_part is/was used with various "read
mmc ..." or "mmc read ..." commands. Guess how well that works when
kernel_part ends up being >= 10 and the U-Boot commands unconditionally
interprets the partition argument as hex...

So what I wanted to do on the U-Boot side is to translate that
$kernel_part into a name ASAP and then use that name exclusively, and
for that the sane semantics of the "part" command came in handy. Except
it lacked the ability to do the translation.

As for the "[not] that usual", `git grep strto -- cmd/` says that the
base argument can be 0, 10 or 16 depending on the phase of the moon -
it's a constant source of pain to figure out how numeric arguments
to commands will be interpreted.

Rasmus