[OpenBIOS] [Qemu-ppc] MorphOS 4.x on QEMU
BALATON Zoltan
balaton at eik.bme.hu
Tue Mar 4 19:27:09 CET 2014
On Tue, 4 Mar 2014, BALATON Zoltan wrote:
> Raise exception at 00441bcc => 00000002 (00)
> IN:
> 0x00000300: b 0xffffc3a0
>
> invalid/unsupported opcode: 00 - 00 - 00 (00000000) ffffc3a0 0
> IN:
> 0xffffc3a0: .long 0x0
>
> Raise exception at ffffc3a4 => 00000006 (21)
> IN:
> 0x00000700: mtsprg 2,r2
> 0x00000704: li r2,7
> 0x00000708: b 0xffffe0f0
>
> invalid/unsupported opcode: 00 - 00 - 00 (00000000) ffffe0f0 0
> IN:
> 0xffffe0f0: .long 0x0
>
> Raise exception at ffffe0f4 => 00000006 (21)
> Raise exception at ffffe0f4 => 00000006 (21)
>
> Something seems to overwrite the vector at 0x300 (which was set to 0x238c
> before this point) but the new value seems to point to the wrong place.
It seems that this is happening when MorphOS tries to install its own
exception handlers but something is going wrong during this. What I think
it does is copying a block of memory with the exception handler vectors
and then it tries to fix up the jumps in it to point to somewhere but
either the fixup is not correct or the handlers are not where they are
expected to be. I'm currently out of ideas how to debug this further.
Regards,
BALATON Zoltan
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