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

Sascha Hauer
2026-04-22T08:25:35Z

On Wed, Apr 22, 2026 at 10:14:11AM +0200, Fabian Pflug wrote:
> On Wed, 2026-04-22 at 09:56 +0200, Sascha Hauer wrote:
> > 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"
>
> Please don't get confused. This is an additional benefit for the CSF in i.MX. The main focus here is to have a string
> representation, that can be used in TLV generation, with the script in
> https://github.com/barebox/barebox/blob/master/scripts/bareboxtlv-generator/bareboxtlv-generator.py
>
> The value
> 0x0024, bound-soc-uid, "Reject TLV if supplied binary data does not match UID SoC register"
> https://github.com/barebox/barebox/blob/v2026.04.0/common/tlv/barebox.c#L200
>
> Needs this representation for all vendors, not just i.MX.
> And since the values for soc_bin and uidstr can differ greatly, it is very soc specific on what value to use in the
> https://github.com/barebox/barebox/blob/master/scripts/bareboxtlv-generator/data-example.yaml
>
> This patch tries to fix it, by giving a value, that can just be copied to TLC data.yaml

Ok, I can much better buy TLV support as an argument.

Please add a

BAREBOX_MAGICVAR(global.soc_uid_hex,
"byte array representation of the raw SoC UID");

Sascha

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