kernfs on the sparc64 port has started not working for rootdev & rrootdev:
   
   # mount -t kernfs /kern /kern
   # ls -l /kern/rootdev
   ls: /kern/rootdev: Bad file descriptor
   # ls -l /kern/rrootdev
   ls: /kern/rrootdev: No such file or directory


this works if one does "ls -l /dev/*wd0b", if booted from wd0b, before
"ls -l /kern/*rootdev"... thanks to a tip from matthias@netbsd.org.


.mrg.