Re: [9fans] exception/interrupt 14 bug - fixed

[Artem Letko <aletko@iname.com>]

Russ is right - after getting the floppy again everything looks good.

Art.

----- Original Message -----
From: "Russ Cox" <rsc@plan9.bell-labs.com>
To: <9fans@cse.psu.edu>
Sent: Monday, May 13, 2002 9:18 PM
Subject: Re: [9fans] exception/interrupt 14 bug


> > The fix doesn't seem to be related to my problem though -
> > exception/interrupt 14 happens much earlier in my case, before the
kernel is
> > fully loaded. The new floppy still panics.
>
> It was the same problem, though.  Here's your register
> dump:
>
> apm ax=f000 cx=f000 dx=0 di=1200 ebx=57a0 esi=c03e6
> using fd0!dos!plan9.ini
> dev A0 port 1F0 config 0C5A capabilities 2F00 mwdma 0007 udma 043F
> pcirouting: 8086/7112 at pin 4 irq 7
> found 9PCFLOP .GZ attr 0x0 start 0xf0 len 1168843
> ...FLAGS=10246 TRAP=e ECODE=0 PC=80015b87
> AX a48003b7 BX 8003b784 CX 00000800 DX 00000000
> SI 8002dcc0 DI 8003b7a4 BP 8003b780
> CS 0010 DS 0008 ES 0008 FS 0008 CS 0008
> CR0 80000011 CR2 a48003b9 CR3 0000c000
> panic: exception/interrupt 14
>
> 57a0+03e6 is 5b86.  Toss in the segment register and
> you've got 80015b86.  Note that you died at 80015b87.
>
> bootpass+0x5fc 0x80015b84 MOVL 0x24(BP),AX
> bootpass+0x5ff 0x80015b87 MOVBSX 0x2(AX),AX
>
> The magic increment turned the first instruction
> into
>
> bootpass+0x5fc 0x80015b84 MOVL 0x25(BP),AX
>
> and you died dereferencing the shifted value.
>
> As for why the disk didn't work, well, let's just
> say that caches are not my friend this week.
>
> If you download a disk now, it should work.
>
> Russ