[coreboot] 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