While I might have missed or botched something else, I now always
get a:

> mountroot: trying nfs...
> nfs_boot: trying DHCP/BOOTP
> nfs_boot: wrong IP addr 0.0.0.0 (bad reply from 134.94.116.81)
> nfs_boot: wrong IP addr 0.0.0.0panic: pool_get(mbpl): free list modified: magic=
> 0; page 0x201000; item addr 0x201380
> 
> Stopped in swapper at   0x91c76:        unlk    a6
> db>

on boot with current sources; this didn't happen with the last kernel
from 2 weeks ago.

best regards
Matthias