Re: [PATCH v11 13/22] gpu: nova-core: Hopper/Blackwell: add FMC signature extraction

[Eliot Courtney]

On Sat May 30, 2026 at 12:09 PM JST, John Hubbard wrote:
> Extract the SHA-384 hash, RSA public key, and RSA signature from the
> FMC ELF32 firmware sections. FSP Chain of Trust verification needs
> these to validate the FMC image during boot.
>
> Co-developed-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> ---
>  drivers/gpu/nova-core/firmware.rs     |  2 +-
>  drivers/gpu/nova-core/firmware/fsp.rs | 90 ++++++++++++++++++++++++++-
>  2 files changed, 88 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
> index 6edb50b83a29..569efee0d4ac 100644
> --- a/drivers/gpu/nova-core/firmware.rs
> +++ b/drivers/gpu/nova-core/firmware.rs
> @@ -641,7 +641,7 @@ fn elf32_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {
>      }
>  
>      /// Automatically detects ELF32 vs ELF64 based on the ELF header.
> -    pub(super) fn elf_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {
> +    pub(crate) fn elf_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {

I think we don't need to widen visibility here.

>          // Check ELF magic.
>          if elf.len() < 5 || elf.get(0..4)? != b"\x7fELF" {
>              return None;
> diff --git a/drivers/gpu/nova-core/firmware/fsp.rs b/drivers/gpu/nova-core/firmware/fsp.rs
> index 011be1e571c2..dc28d0cc2d03 100644
> --- a/drivers/gpu/nova-core/firmware/fsp.rs
> +++ b/drivers/gpu/nova-core/firmware/fsp.rs
> @@ -15,13 +15,35 @@
>      gpu::Chipset, //
>  };
>  
> +/// Size of the FSP SHA-384 hash, in bytes.
> +pub(crate) const FSP_HASH_SIZE: usize = 48;
> +/// Maximum size of the FSP public key (RSA-3072), in bytes.
> +///
> +/// The FMC ELF `publickey` section may be shorter, so the remaining bytes are zero-padded.
> +pub(crate) const FSP_PKEY_SIZE: usize = 384;
> +/// Maximum size of the FSP signature (RSA-3072), in bytes.
> +///
> +/// The FMC ELF `signature` section may be shorter, so the remaining bytes are zero-padded.
> +pub(crate) const FSP_SIG_SIZE: usize = 384;

These constants look unused outside of this file to me so we can keep
them private.