https://bugs.freedesktop.org/show_bug.cgi?id=79773
--- Comment #2 from Alex Deucher agd5f@yahoo.com --- looks like the vbios didn't get dumped properly. Try this:
(as root) (use lspci to get the bus id) cd /sys/bus/pci/devices/<pci bus id> echo 1 > rom cat rom > /tmp/vbios.rom echo 0 > rom