Subject: Re: debug
To: S Dobson <sd20@york.ac.uk>
From: Matthew Orgass <darkstar@city-net.com>
List: port-hpcmips
Date: 08/16/2004 15:46:45
On 2004-08-16 sd20@york.ac.uk wrote:

> Ok, my z50 crashed again today, I was connected to the network, but just
> looking at my local files with 'cd' and 'ls' - It didn't put me into
> debug it just froze after spitting out this message:
>
> Trap: reserved instruction in kernel mode status=0x120782, cause=0x28,
> epc=0x8028f448,
> Vaddr=0xc3311f8 pid=7 cmd=ioflush usp=0x0 ksp=0x80001450
> Stopped in pid7 (ioflush) at 0x8028f448: spec12 zero,zero,zero

  If I am reading the disassembly code right, this is movz zero,zero,zero
which is a Mips IV instruction.  It's encoding contains only a single one
bit, so it might be a hardware problem.  If you have built cross tools (or
installed the compiler natively) you can do:
/usr/mtools/bin/mipsel--netbsd-objdump -D netbsd | grep "^8028f448" to see
what your kernel says (mtools = your too directory; for native objdump
just use objdump).  This should be done on the kernel you are actually
using, as it might be a disk error, and if that shows the same instruction
(objdump might also consider it to be "ffs zero, zero" or not disassemble
it; the code should be 0xA)  then check, if possible, the same kernel that
has not been copied to that disk.  If the instruction is different in the
kernel file, it is most likely memory I would guess, although there are a
few other possibilities as well (such as compiler error or kernel memory
being overwritten).

> 1> win CE often complains about my 1gb IBM microdrive  - sometimes I
> need to take it out and put it back in for it to be readable.  Don't
> know if that's normal but could netbsd also have these problems causing
> kernel errors?

  A disk error might be able cause this, but I have found CE to often be
upset at disks for no apparant reason.

> 2> Don't know if this was right, but after installing netbsd onto the CF
> card using boot.exe in win CE the boot loader would complain saying that
> it can't find \storage card\netbsd-GENERIC.  So I copied (and renamed)
> netbsd-GENERIC to root (/netbsd) and altered /etc/rc.d/sysdb to contain
> the line: kvm_mkdb "/netbsd" - don't know if that's ok or not but it
> seemed to stop it from complaining ;-)

  I think what you did is the right thing to do.

Matthew Orgass
darkstar@city-net.com