AMD Family 15tn/16: What is `…HookGfxGetVbiosImage` needed for?

[Paul Menzel]

Dear coreboot folks,

why does AGESA need the Video BIOS hook for Family 15tn (Trinity) and
Family 16 (Kabini)?

$ more src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c
        […]
        AGESA_STATUS fam15tn_HookGfxGetVbiosImage(UINT32 Func, UINT32 FchData, VOID *ConfigPrt)
        {
        	GFX_VBIOS_IMAGE_INFO  *pVbiosImageInfo = (GFX_VBIOS_IMAGE_INFO *)ConfigPrt;
        	pVbiosImageInfo->ImagePtr = cbfs_get_file_content(
        			CBFS_DEFAULT_MEDIA, "pci"CONFIG_VGA_BIOS_ID".rom",
        			CBFS_TYPE_OPTIONROM);
        	/* printk(BIOS_DEBUG, "IMGptr=%x\n", pVbiosImageInfo->ImagePtr); */
        	return pVbiosImageInfo->ImagePtr == NULL ? AGESA_WARNING : AGESA_SUCCESS;
        }

Looking through

src/vendorcode/amd/agesa/f15tn/Legacy/Proc/agesaCallouts.c

I do not see what this is needed for.

Thanks,

Paul

[Martin Roth]

AGESA will disable the onboard graphics device if a pointer to the 
videobios isn't passed in.
Martin

On 11/06/2013 03:48 PM, Paul Menzel wrote:
> Dear coreboot folks,
>
> why does AGESA need the Video BIOS hook for Family 15tn (Trinity) and
> Family 16 (Kabini)?
>      $ more src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c
>      […]
>      AGESA_STATUS fam15tn_HookGfxGetVbiosImage(UINT32 Func, UINT32 FchData, VOID *ConfigPrt)
>      {
>      	GFX_VBIOS_IMAGE_INFO  *pVbiosImageInfo = (GFX_VBIOS_IMAGE_INFO *)ConfigPrt;
>      	pVbiosImageInfo->ImagePtr = cbfs_get_file_content(
>      			CBFS_DEFAULT_MEDIA, "pci"CONFIG_VGA_BIOS_ID".rom",
>      			CBFS_TYPE_OPTIONROM);
>      	/* printk(BIOS_DEBUG, "IMGptr=%x\n", pVbiosImageInfo->ImagePtr); */
>      	return pVbiosImageInfo->ImagePtr == NULL ? AGESA_WARNING : AGESA_SUCCESS;
>      }
>
> Looking through
>      src/vendorcode/amd/agesa/f15tn/Legacy/Proc/agesaCallouts.c
>
> I do not see what this is needed for.
>
> Thanks,
>
> Paul