All I did was edit the SHEEVAPLUG kernel a little bit with the advice of others.
My main concern is Ethernet driver but it seems to be there (mvgbe).
If you can get to the firmware and netboot it, there might be an evbarm kernel which is pretty close.
I need to do some soldering to get access to the com port. If I get it up and running I will report back with kernel config options.
Carsten