[PATCH] cmd: fdt: Add support for reading stringlist property values

[Simon Glass]

Hi Marek,

On Fri, 8 Jul 2022 at 15:50, Marek Vasut <marex at denx.de> wrote:
>
> The fdt command currently handles stringlists as strings in 'fdt get value'
> subcommand. Since strings in FDT stringlists are separated by '\0', only
> the first value gets inserted into the environment variable passed to the
> 'fdt get value' command.
>
> Example, consider the following DT snippet:
>
> / { compatible = "foo", "bar" };
>
> The following command only reports the first string in stringlist:
> => fdt get value var / compatible ; print var
> foo
>
> It is not possible to assign list of null-terminated strings into U-Boot
> environment variable. Add optional 'index' parameter to the subcommand
> 'fdt get value <var> <path> <prop> [<index>]' which lets user specify which
> string within the stringlist should be assigned into the 'var' variable.
> The default value of 'index' is 0 in case it is not present. This way the
> 'fdt' command API does not change and existing scripts are not broken.
>
> The following command now reports the Nth string in stringlist, counting
> from zero:
> => fdt get value var / compatible 1 ; print var
> bar
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Tom Rini <trini at konsulko.com>
> ---
>  cmd/fdt.c | 34 ++++++++++++++++++++++++++++------
>  1 file changed, 28 insertions(+), 6 deletions(-)

Can you please add docs and a test?

I am happy to do a starting point for a test if you like.

Regards,
Simon