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Ben Collver wrote:
> The confusing part is in query_pcbios(), at line 730 of head.S
>         xorl    %eax, %eax
>=20
> At this point in the function, bochs is in real mode.  I expected the xorl
> to cause eax to be zeroed out, but instead it zeroes cs and sets eip to 2.
> Can someone advise me if this is a quirk of the 80386 in real mode, or if
> it looks like a bug in bochs?

There's definately no such side-effect of "xor eax,eax". You can use all 32=
-bit
registers in real-mode just like in protected mode. I'd even say to enter
the latter successfully you have to use them. However, it's unlikely that t=
he
emulation is buggy here because a lot of DOS apps use 32-bit registers etc.
Though I haven't used bochs in quite a while. I'd guess it's rather a probl=
em
of the debugger. Maybe it damaged the stack or an interrupt got in-between.

--=20
Christian

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