Subject: Re: memtest86 in bochs
To: None <port-i386@netbsd.org>
From: Ben Collver <collver1@comcast.net>
List: port-i386
Date: 01/05/2004 10:20:42
On Mon, Jan 05, 2004 at 05:41:34PM +0100, Christian Biere wrote:
> > 0000265d: sti                       ; fb
> 
> Here you allow interrupts (unless the PIC is programmed to disable them)
> and a few instructions later something goes haywire. Suspicious.
> 
> > 0000265e: xor EAX, EAX              ; 6631c0
> > 00002661: mov [DS:0000], EAX        ; 66a30000
> > 00002665: mov [DS:0004], EAX        ; 66a30400
> > 00002669: mov [DS:0008], EAX        ; 66a30800
> > 0000266d: xor EBX, EBX              ; 6631db

If I make a breakpoint at the first instruction after 'cli' ni
query_pcbios(), bochs never gets there.  It gets stuck in a loop of:

00006130453i[CPU  ] BxError: instruction with op1=0xfe
00006130453i[CPU  ] nnn was 7
00006130453i[CPU  ] WARNING: Encountered an unknown instruction (signalling illegal instruction):

When I break out of it, I find CS:IP is at 0:0.  Something's going on in
there that shouldn't be, I'll see if I can narrow it down a bit.

Cheers,

Ben
-- 
A hacker does for love what others would not do for money.