Re: [Qemu-devel] Boot failure with MS-Dos 6.22 (due to bad BIOS build?)

[Jan Kiszka]

On 2012-02-27 10:51, Daniel P. Berrange wrote:
> I'm seeing current QEMU GIT fail to boot MS-Dos 6.22 with the following
> crash:
> 
> # qemu-system-x86_64 -fda ~/MS-DOS\ 6.22.img  -m 1 -curses
> iPXE v1.0.0-591-g7aee315
>                                  iPXE (http://ipxe.org) 00:03.0 C900 PCI2.10 
> PnP PMM+00000000+00000000 C900
> 
>                                  Booting from Floppy..
> .                                qemu: fatal: Trying to execute code outside 
> RAM or ROM at 0x00000001000effff
> 
> EAX=ffffffff EBX=ffffffff ECX=0000c934 EDX=00000068
> ESI=00006801 EDI=00000000 EBP=0000002b ESP=0000fff5
> EIP=ffffffff EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =0040 00000400 0000ffff 00009300
> CS =f000 000f0000 0000ffff 00009b00
> SS =9ec4 0009ec40 0000ffff 00009300
> DS =9ec4 0009ec40 0000ffff 00009300
> FS =0000 00000000 0000ffff 00009300
> GS =0000 00000000 0000ffff 00009300
> LDT=0000 00000000 0000ffff 00008200
> TR =0000 00000000 0000ffff 00008b00
> GDT=     000fcd78 00000037
> IDT=     00000000 000003ff
> CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 
> DR3=0000000000000000 
> DR6=00000000ffff0ff0 DR7=0000000000000400
> CCS=000000d0 CCD=00000068 CCO=SARL    
> EFER=0000000000000000
> FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
> FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
> FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
> FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
> FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
> XMM00=00000000000000000000000000000000 XMM01=00000000000000000000000000000000
> XMM02=00000000000000000000000000000000 XMM03=00000000000000000000000000000000
> XMM04=00000000000000000000000000000000 XMM05=00000000000000000000000000000000
> XMM06=00000000000000000000000000000000 XMM07=00000000000000000000000000000000
> Aborted
> 
> 
> Git bisect blames this
> 
>   commit 41bd360325168b3c1db78eb7311420a1607d521f
>   Author: Jan Kiszka <address@hidden>
>   Date:   Sun Jan 15 17:48:25 2012 +0100
> 
>     seabios: Update to release 1.6.3.1
>     
>     User visible changes in seabios:
>      - Probe HPET existence (fix for -no-hpet)
>      - Probe PCI existence (fix for -machine isapc)
>      - usb: fix boot paths
>     
>     Signed-off-by: Jan Kiszka <address@hidden>
> 
> 
> I tried to bisect Seabios, but every revision in Seabios upstream works
> fine.
> 
> Then I noticed, that if I rebuild the BIOS, from the exact same revision
> 1.6.3.1 revision that is committed in 'seabios' submodule in QEMU, then
> it works fine. So AFAICT, it is not the Seabios source code at fault,
> but rather the binary build we have commited to GIT. Should/can we rebuild
> the bios.bin in GIT ?

Probably not without understanding what causes this strange
inconsistency. If Seabios builds without errors and then later on fails,
this is also a bug.

Kevin, what information do you need to assess my tool chain?

Jan

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