I had a 7500 built and otherwise good to go (it would reboot and come up all
pretty).  I was going for closure by putting it all back together and when I
went to boot it, no boot disk.  Alas, openfirmware patch.  It would boot
when I did the power-cycle after the drive had spun up, so my task was
pretty clear.

So I pulled the netbsd disk out (no HFS[+]/Apple partitions) and put in a
beater drive with MacOS 9.1.  Pulled down the "right" SystemDisk, patched it
with the "right" patch just like the web page suggests for the chaos
critters like this.  I populated the Advanced page with:

 scsi-int/sd@0:0
 <boot-file is blank>
 <standard 'boot' command>
 ttya  ttya
 don't boot

Now it appears load the kernel but fails to mount / or exec the kernel.  The
machine stops after writing out to the screen:

>> NetBSD/macppc OpenFirmware Boot, Revision 1.2
>> (matt@duel.local, Sat Aug 18 13:46:09 PDT 2001)
2931828+237444 [100+106512|

And that's where she freezes.  It's still the GENERIC kernel if that's any
help.  What should my next step be?

Virt-base is 600000, do I need to fiddle with these parms like on other
older models?

Is there a signal that I can do to reset the box after it freezes like this
if I'm connected via serial console?  Should I be able to use the built-in
video as a console if I set back to kbd /chaos/control?

Thoughts?