I have done some interesting test. I plug one display adapter to the MB, and let linuxbios excute onboard vga option rom at first, and then option rom in addon card. Then power down and I unplug the add on card At last boot the system, after linuxbios, it works well.
The option rom in Adapter init the Font Mem and it can last some time even power off the MB....Funny.....
YH