Zheng,
From the K8 log:
PCI: 00:02.0: enabled 0, 0 resources PCI: 00:03.0: enabled 0, 0 resources
These devices are enabled for fam10, but disabled for the K8 board. I thought the only difference was supposed to be the processor/northbridge.
Because of that, rs780_gfx_init doesn't get run. UMA is also different.
I'm not sure what's actually breaking it, but it would be easier to tell if you minimize some of those differences.
Thanks, Myles