>>       kernel crashes after determining root filesystem type:
>>       run NetBSD/current on a decstation5000/260.
>
> This is a known problem - it's been discussed a little on the pmax list
> over the last week or so.  I guess this doesn't help you (or me!) much,
> but people are looking into it...

According to simonb's report of May 29, DS5000/260 is boggled down as; 

        boot device: rz2
        root on rz2a dumps on rz2b
        root file system type: ffs
        trap: TLB miss (load or instr. fetch) in kernel mode
        status=0x7c02, cause=0x808, epc=0x80032990, vaddr=0x3ff000
        pid=1 cmd=init usp=0x7ffffdf8 ksp=0xc5ad9d30
        Stopped in init at      0x80032990:     cache   zero,a0,0

Assuming the 'vaddr' shows a correct value, it's a very weird result
because statically linked '/sbin/init' has no text address range of
0x3ff000 (around 4MB).  If mips3_FlushICache() really tries to flush
processor's I-cache searching 0x3ff000, it's an expected behaviour for
kernel to post an exception.  Hint, hint?

Tohru Nishimura