Hi,
I'm having issues to use an Ati x600se 128mb GPU (OEM DELL) with my KGPE-D16. With ASUS BIOS, the card works fine (either in first or second pcie-x16 slot) With coreboot, no video output. The board still boots but the card isn't detected at all. (either in first or second pcie-x16 slot) I don't know what is the issue since I was using a GTX660 before without issue.
It seems like you are not using SeaBIOS. Normally, Seabios initializes PCI devices. Are you sure you are using the same coreboot configuration that worked fine for your GTX660 with this ATI card or did you rebuild/reflash coreboot inbetween?
Do I need to embed the VGA rom in cbfs for this card ?
No, afaik the VGA rom is only needed for native gfx init on (some) devices with embedded graphics but not for add-on pci(e) cards.
Cheers, Daniel