coreboot

Does EDK2 MrChromebox 26.09.2 load a VBIOS bin file from CBFS added with CONFIG_VGA_BIOS and runs it like SeaBIOS does for laptops with dGPU? Tried it with and without the CONFIG_EDK2_LOAD_OPTION_ROMS:y setting?

For a while EDK2 MrChromeBox payload caries support for loading VBIOS from real physical PCIe dGPU's using CONFIG_EDK2_LOAD_OPTION_ROMS:y if they have a matching 64-bit EFI GOP. This has worked fine for me on real desktop boards with PCIe dGPU's from sandybridge to coffeelake both with AMD and NVIDIA dGPU's even combined with libgfxinit intel iGPU's.

Currently on coreboot 26.09-14-ge0eec9336f54 for the macbookpro10,1 CB:32673 it works fine with SeaBIOS 1.17. Switching from only Intel to only NVIDIA keeps SeaBIOS bootscreen and makes built-in display, both miniDP and HDMI output work if using NVIDIA. While only using CONFIG_VGA_BIOS with 10de,0fd5 a uefiextract supplied VBIOS bin and not even using the Kconfig 2nd or discrete VGA options (since the Intel iGPU uses libgfxinit).

When using EDK2 MrChromebox 26.09.2 forced to only NVIDIA the built-in display remains off during post/boot (no bunny neither on both miniDP ports nor HDMI port). However the OS nouveau driver detects the VBIOS in its CBFS/ACPI table and all video outputs start working fine including sound output. Currently only Intel iGPU output works fine with EDK2 bootscreen.

Any thoughts how to debug or even research if my VBIOS file has a correct EFI GOP in it?

By default both EDK2 and SeaBIOS builds are build with libgfxinit support and not using the coreboot way of running the VBIOS from CBFS but let the payload do it which works for SeaBIOS.