Anybody help shed any lite on this??

I have previously successfully run NetBSD on this MacIIx, but now it
hangs at this point early in the boot process:

adb: bus subsystem

......forever!

I've tried my original 1.2 installation, and also have tried the 1.2.1
that I've recently installed on an external SCSI for my IIci's.  Both
fail exactly the same way, at exactly that point in the boot.  Nothing
else, the machine is dead, and must be shut down totally to get it to
come back to life.  Have tried different keyboard, mouse, etc, with no
change.....All is fine under MacOS 7.1.

Paul