Re: [PATCH v2 1/2] common: misc: add soc_uid_hex to globalvar

[Sascha Hauer <s.hauer@pengutronix.de>]

On Wed, Apr 15, 2026 at 01:10:21PM +0200, Fabian Pflug wrote:
> uidstr and uidbuf could be the same, but don't have to be. This results
> in uncertainty on what exactly is the current UID used for
> machine_set_hashable and to compare against with TLV.
> 
> Add an additional global var, that encodes SoC-UID registers in a
> manner uniform across SoCs/manufacturers.
> 
> This can now be used to feed as data for bound-soc-uid into
> `bareboxtlv-generator.py` or as the value for
> `CONFIG_HABV4_CSF_UNLOCK_UID`
> 
> Signed-off-by: Fabian Pflug <f.pflug@pengutronix.de>
> ---
>  common/misc.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/common/misc.c b/common/misc.c
> index ecf9574f7a..be896706d6 100644
> --- a/common/misc.c
> +++ b/common/misc.c
> @@ -268,6 +268,7 @@ const uuid_t *barebox_get_product_uuid(void)
>  BAREBOX_MAGICVAR(global.product.uuid, "SMBIOS-reported product UUID");
>  
>  static char *soc_uid_str;
> +static char *soc_uid_bin_str;
>  static void *soc_uid;
>  static size_t soc_uid_len;
>  
> @@ -295,18 +296,22 @@ void barebox_set_soc_uid(const char *uidstr, const void *uidbuf, size_t len)
>  	soc_uid = xmemdup(uidbuf, len);
>  	soc_uid_len = len;
>  
> +	soc_uid_bin_str = xzalloc(len * 2 + 1);
> +	bin2hex(soc_uid_bin_str, uidbuf, len);
> +
>  	if (uidstr) {
>  		soc_uid_str = xstrdup(uidstr);
>  	} else {
> -		soc_uid_str = xzalloc(len * 2 + 1);
> -		bin2hex(soc_uid_str, uidbuf, len);
> +		soc_uid_str = soc_uid_bin_str;
>  	}
>  
>  	machine_id_set_hashable(uidbuf, len);
>  
>  	globalvar_add_simple_string("soc_uid", &soc_uid_str);
> +	globalvar_add_simple_string("soc_uid_hex", &soc_uid_bin_str);

barebox_set_soc_uid() takes two arguments, the raw SoC UID data and a
SoC specific string representation of that data. It's unfortunate that
you need two different interpretations of the raw data on i.MX, one to
match the Linux /sys/ format and one to put into the CSF file.

Anyway, just adding a second string representation not only for i.MX,
but also for all other SoCs is rather confusing. For the i.MX field
return case we could also add a hab command option or a i.MX specific
globalvar which is exactly described as "SoC UID in the format the CSF
needs"

Sascha

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