[PATCH 4/5] tools: Add dumpfwumdata tool for FWU metadata image

[Kory Maincent]

On Mon, 12 Jan 2026 10:05:50 +0100
Michal Simek <monstr at monstr.eu> wrote:

> On 1/11/26 16:17, Dario Binacchi wrote:
> > Hello Michal,
> > 
> > On Mon, Jan 5, 2026 at 4:40 PM Michal Simek <monstr at monstr.eu> wrote:  
> >>
> >> ne 28. 12. 2025 v 16:19 odesílatel Dario Binacchi
> >> <dario.binacchi at amarulasolutions.com> napsal:  
> >>>
> >>> Allow reading FWU metadata from userspace.
> >>>
> >>> According to [1], after updating the software on bank B, setting
> >>> active_index to point to it (i. e. 1) and marking it as a Valid bank, it
> >>> must be possible to read this information from userspace on the next
> >>> boot to verify whether the boot chain of bank B succeeded.
> >>>
> >>> The metadata must then be updated again, marking the bank as INVALID if
> >>> the active_index points to bank A (i. e. 0) or as VALID if the boot was
> >>> successful.
> >>>
> >>> To allow reading the active_index and bank state, this new tool has been
> >>> added.
> >>>
> >>> Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>

...

> >>> +}
> >>> +
> >>> +static int fwu_read_mdata(struct fwu_mdata *mdata, const char
> >>> *mdata_file) +{
> >>> +       FILE *mfile = NULL;
> >>> +       size_t ret, size = sizeof(struct fwu_mdata);
> >>> +
> >>> +       mfile = fopen(mdata_file, "r");
> >>> +       if (!mfile) {
> >>> +               fprintf(stderr, "Error: Failed to open %s\n",
> >>> +                       mdata_file);
> >>> +               return -1;
> >>> +       }
> >>> +
> >>> +       ret = fread(mdata, 1, size, mfile);
> >>> +       fclose(mfile);
> >>> +       if (ret != size) {
> >>> +               fprintf(stderr, "Error: Failed to read from %s\n",
> >>> +                       mdata_file);
> >>> +               return -1;
> >>> +       }
> >>> +
> >>> +       return 0;
> >>> +}
> >>> +
> >>> +int main(int argc, char *argv[])
> >>> +{
> >>> +       int c, ret;
> >>> +       struct fwu_mdata mdata;
> >>> +
> >>> +       if (argc < 3) {
> >>> +               print_usage();
> >>> +               return -EINVAL;
> >>> +       }  
> >>
> >> above you have only help and here you are asking for 3 args which
> >> seems to me wrong.  
> > 
> > Thank you for your review and the feedback on my patch series.
> > After I sent the series, I realized that this series had previously
> > been posted:
> > https://lore.kernel.org/all/20251212-feature_fwumdata-v2-0-ad51572fbe79@bootlin.com/.
> >  From what I understand, it starts from the same need as mine, namely
> > the implementation of a tool that
> > allows reading FWU metadata from Linux. My version is definitely more
> > minimal compared to what Kory
> > has done.
> > Therefore, before sending a v2, I think it would be useful to
> > understand which of the two makes more sense
> > to move forward with. Could you help me with that? I have also CCed
> > Kory to keep the discussion shared.  
> 
> Kory's version looks more complete. If Kory is happy to send another version
> I think you should test it, review it. If he is not going to send v3 I think
> you should merge your series with his and send another version.

Hello,

I was going to ping reviews on my series.
I will be glad to send a 3rd version but there will be no change from v2 as
nobody reviewed it for now, but if needed I can resend it.
It would be nice if you review and test it on you side to know if it match your
requirements.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com