Re: [PATCH v3 16/19] nova-core: Add support for VBIOS ucode extraction for boot

[Joel Fernandes <joelagnelf@nvidia.com>]

On 5/16/2025 4:38 PM, Timur Tabi wrote:
> n Wed, 2025-05-07 at 22:52 +0900, Alexandre Courbot wrote:
>> +impl FwSecBiosImage {
>> +    fn setup_falcon_data(
>> +        &mut self,
>> +        pdev: &pci::Device,
>> +        pci_at_image: &PciAtBiosImage,
>> +        first_fwsec_image: &FwSecBiosImage,
>> +    ) -> Result<()> {
>> +        let mut offset = pci_at_image.falcon_data_ptr(pdev)? as usize;
>> +
>> +        // The falcon data pointer assumes that the PciAt and FWSEC images
>> +        // are contiguous in memory. However, testing shows the EFI image sits in
>> +        // between them. So calculate the offset from the end of the PciAt image
>> +        // rather than the start of it. Compensate.
>> +        offset -= pci_at_image.base.data.len();
>> +
>> +        // The offset is now from the start of the first Fwsec image, however
>> +        // the offset points to a location in the second Fwsec image. Since
>> +        // the fwsec images are contiguous, subtract the length of the first Fwsec
>> +        // image from the offset to get the offset to the start of the second
>> +        // Fwsec image.
>> +        offset -= first_fwsec_image.base.data.len();
>> +
>> +        self.falcon_data_offset = Some(offset);
>> +
>> +        // The PmuLookupTable starts at the offset of the falcon data pointer
>> +        self.pmu_lookup_table = Some(PmuLookupTable::new(&self.base.data[offset..])?);
>> +
>> +        match self
>> +            .pmu_lookup_table
>> +            .as_ref()
>> +            .ok_or(EINVAL)?
>> +            .find_entry_by_type(FALCON_UCODE_ENTRY_APPID_FWSEC_PROD)
>> +        {
>> +            Ok(entry) => {
>> +                let mut ucode_offset = entry.data as usize;
>> +                ucode_offset -= pci_at_image.base.data.len();
>> +                ucode_offset -= first_fwsec_image.base.data.len();
>> +                self.falcon_ucode_offset = Some(ucode_offset);
>> +                if cfg!(debug_assertions) {
>> +                    // Print the v3_desc header for debugging
>> +                    let v3_desc = self.fwsec_header(pdev.as_ref())?;
>> +                    pr_info!("PmuLookupTableEntry v3_desc: {:#?}\n", v3_desc);
>> +                }
>> +            }
>> +            Err(e) => {
>> +                dev_err!(
>> +                    pdev.as_ref(),
>> +                    "PmuLookupTableEntry not found, error: {:?}\n",
>> +                    e
>> +                );
> Shouldn't you return an error here?
> 
> If not, then maybe this should probably be dev_warn.

Good catch, fixed! Thanks,

 - Joel