Re: BTX halted during install

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Wed, 22 Jun 2005 11:16:57 -0400
On Wednesday 22 June 2005 05:02 am, Hajimu UMEMOTO wrote:
> Hi,
>
> >>>>> On Tue, 21 Jun 2005 14:43:10 -0400
> >>>>> John Baldwin <jhb_at_FreeBSD.org> said:
>
> jhb> Hmm, well.  First off, try disabling DMA for the hard drive and CD-ROM
> in the jhb> BIOS.  Secondly, you can hack on btx to add a while (1) loop
> ('foo: jmp foo') jhb> and move it around to get it to stop looping after
> the first fault so you can jhb> capture the details.  I can help you with
> that if you aren't familiar with jhb> x86 assembly.  Once that is done, I
> can look at the fault details to try to jhb> figure out what your BIOS is
> doing that is making the machine unhappy.
>
> Unfortunately, it seems there is no such setting in BIOS menu to
> disabling DMA.
>
> I did patch to stop looping and got the message:
>
> 	http://www.imasy.or.jp/~ume/FreeBSD/CF-R4/cf-r4-btx-halted.jpg
>
> I heared from takawata-san that EIP=0x107 indicates runaway.
>
> I could install FreeBSD by PXE boot from
> 6.0-CURRENT-SNAP004-i386-disc1.iso.  It's fine to boot FreeBSD which
> is installed on HDD.
>
> It seems BTX-halted occurs when loading loader or kernel via legacy
> USB.  I heared from Panasonic folks that they improved their legacy
> USB code for their latest series including CF-R4.  It seems there is
> some issue in their improvement, and our BTX hits the weak point of
> their improvement.  However, DOS, Windows and NetBSD are still
> bootable on CF-R4...
>
> Sincerely,

00000000  F065F000F0        gs lock add al,dh
00000005  B182              mov cl,0x82
00000007  00C0              add al,al
00000009  B221              mov dl,0x21
0000000B  00F0              add al,dh
0000000D  B221              mov dl,0x21
0000000F  00F0              add al,dh
00000011  B221              mov dl,0x21
00000013  00F0              add al,dh
00000015  B221              mov dl,0x21
00000017  00F0              add al,dh
00000019  B221              mov dl,0x21
0000001B  00F0              add al,dh
0000001D  B221              mov dl,0x21

That definitely looks like garbage code.  I believe that most other OS's don't 
try to use the BIOS from vm86 mode the way that FreeBSD does.  Windows at 
least doesn't, so BIOS writers tend to break the vm86 case because they don't 
test it or don't care enough to even consider it.

-- 
John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org
Received on Wed Jun 22 2005 - 13:24:20 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:37 UTC