https://bugs.freedesktop.org/show_bug.cgi?id=64850
--- Comment #17 from Jakob Nixdorf flocke@shadowice.org --- Created attachment 79737 --> https://bugs.freedesktop.org/attachment.cgi?id=79737&action=edit ROM Dump
I played around some more. I compiled my kernel with UMS enabled and booted with 'radeon.modeset=0' which resultet in the 'radeon' module beeing loaded successful and without the 'Invalid ROM contents' error. Also both screens are active in the TTY. After running 'rmmod radeon && modprobe -v radeon modeset=1' the DVI-0 screen goes black again and the TTY is only shown on HDMI-0. Also the 'Invalid ROM contents' error shows up again.
Additionally I made a dump of the ROM ('echo 1 > /sys/bus/pci/devices/0000:01:00.0/rom && cat /sys/bus/pci/devices/0000:01:00.0/rom > rom-dump'), because this error somehow bugs me ;) maybe it can help.