Hi all!
Working a little on $SUBJECT, I found a few patches to be necessary to get it all running. It's far from perfect yet, but I wanted to share with you what I found so far.
I had to make the config change to Open Firmware similar to that on the openbios wiki, and change 4 things in the LinuxBIOS source. I'll post these to the individual lists now.
Thanks a lot for the work I could build upon!
Torsten