So I finally have some free time, so I downloaded netbsd-current (1.5R)
and fixed a number of things for the 4000SC/PC, including rewriting the
pica_clkintr code to use the cpu's counter/compare registers since the
R4030 interval timer seems broken on the Magnum (and lack of any documentation
on the Magnum has made pursuing this futile).  Everything seems to working
a-ok so far, only problem is once I get to process 0 (swapper), it just stops.
I can send a hard break and get to DDB just fine, but the stack trace doesn't
show anything unusual.  I can continue and break again at will, so the system
isn't hung.  I just don't seem to be getting beyond the swapper process.
The last thing displayed on the screen is the autoconf of the com ports,
which are obviously working.  The next thing that SHOULD happen is root
device selection, but I'm not getting that far.  The kernel is configured
for NFS/BOOTPARAM/etc for root.  Is there anything broken I should know about
in 1.5R?  And any guesses as to why process 0 just keeps spinning its wheels
but never goes to the next step?

Thanks,
-Mark

P.S.: Once I get this working, I post all my patches so they can be committed.
A number of the patches are actually based on Maki Kato's contributions, with
some cache fixes, etc.