Is there a canonical list of options for the kernel config file?
   I am trying to compile a kernel with HPIB support and seem to be
   meeting with limited success.  I have an HPIB tape drive as my only
   HPIB device (boot from a scsi disk).  

Did you look in the example config files?  You should be able to:

master		hpib0	at scode?
tape		ct0	at hpib? slave ?

and have it work.

   I also am having trouble with rbootd -- it claims that the bpf is also
   not configured, although I have it listed as a pseudo device in my kernel
   config file.

The major number for bpf in /dev/MAKEDEV used to be wrong.  It should
be 22, not 105.