Michael Thompson writes:
 > In PCspeak the plug-and-play BIOS enumerates the PCI bus when it
 > pokes at known addresses to see if a board is installed and to
 > figure out what is installed there.
 > 
 > A UNIX kernel does the same thing when it boots by looking for
 > onboard I/O and VMEbus I/O at known addresses.
 > 
 > It is also called a discovery process.

The relevant messages are:

vme0 at mainbus0: (A16/D16)
vme1 at mainbus0: (A16/D32)
vme2 at mainbus0: (A24/D16)
vme3 at mainbus0: (A24/D32)
vme4 at mainbus0: (A32/D16)
vme5 at mainbus0: (A32/D32)

But, looking at this and thinking back over what I've heard about VME, 
I would guess these are the VME address spaces that devices can appear 
in and I've just misinterpreted them, haven't I...

Anyway, the 'spurious level 2 interrupt' answer would appear to have
to do with the VME backplane's jumpers.  I now have a vague idea about 
what they do, and I assume that one of the cards I removed should have 
been replaced by a jumper.  Replacing the original cards makes it work 
with the SunOS 3.5 install.

By the way, whoever said I should have a P2 bridge between the memory
and the processor is wrong.  In fact, the memory is there for the use
of the dedicated hardware, and is used over the VME bus.  It's not
part of the Sun's core memory.

Anyway: does NetBSD support a Sun3/E SCSI controller by default?  The
address is 310000, which, admittedly, isn't the same as usual, but is
exactly right for a Sun3/E, according to my manual.  If it doesn't,
then it would be since if the sun3 page mentioned it.  I should point
out I haven't tried a sun3 + netbsd boot yet, so I can't say if the
jumper/card fix has changed matters.


-- 
Ian.