Re: [PATCH v12 13/22] gpu: nova-core: Hopper/Blackwell: add FMC signature extraction

[John Hubbard]

On 6/2/26 8:09 PM, Timur Tabi wrote:
> On Wed, 2026-06-03 at 09:20 +0900, Alexandre Courbot wrote:
> > > How can we be certain that these lengths are really fixed?  I can add these length
> > > restrictions to
> > > the script that generates the files, but I want to be really certain that they will be
> > > correct for
> > > all time.
> >
> > These are RSA-3072 keys/signatures, which are by convention 384 bytes
> > (or 3072 bits), so I think we can rely on that assumption as long as the
> > content type doesn't change. I am actually surprised that the comment
> > says the section can be shorter - that doesn't sound possible with
> > RSA-30272 .

I recall repeatedly hitting cases on one of the GPU architectures that
used a shorter length, but I should go back and verify that it wasn't
just a bringup "conclusion" that doesn't hold up after the dust settled.

> I'm assuming that maybe they could be RSA-2048.
>
> > Does the script have a way to validate the length? If so, I agree it is
> > a good idea to do so, to flag the problem before it shows up in the
> > driver.
>
> Yes, I will add these length checks.

thanks,
--
John Hubbard