Re: [coreboot] Error executing VGA ROM with coreboot

[Joseph Smith]

On Fri, 30 Oct 2009 17:32:03 +0530 (IST), [e-mail] wrote:
> > On Fri, 30 Oct 2009 10:11:36 +0530, "Mansoor" 
> > wrote:
> > > > -----Original Message-----
> > > > From: Joe [mailto:[e-mail]]
> > > > Sent: Thursday, October 29, 2009 7:32 PM
> > > > To: Mansoor
> > > > Cc: 'coreboot'
> > > > Subject: Re: [coreboot] Error executing VGA ROM with coreboot
> > > >
> > > > On 10/29/2009 07:38 AM, Mansoor wrote:
> > > > > Hi
> > > > >
> > > > > I keep getting "ILLEGAL EXTENDED X86 OPCODE!" from my VGA ROM while
> > > > > trying run VGA ROM in coreboot.
> > > > >
> > > > > I tried x86emu, yabel and real mode for running VGA ROM with no

luck.
> > > > > But the same VGA ROM is running with seabios.
> > > > >
> > > > > I am attaching the boot logs with x86emu, real mode and with

seabios.
> > > > > Any help?
> > > > >
> > > > > What is the big difference while executing VGA ROM in coreboot and
> > > >
> > > > seabios?
> > > > > Why coreboot can't run a VGA ROM which seabios can?
> > > >
> > > > Hmm looks like your getting Unexpected Exception errors. Something is
> > > > not initializing correctly. Memory maybe?
> > >
> > > I don't think so, because with seabios I am able to load Linux in GUI
> >
> > mode.
> > > Only with coreboot I am facing these issues for initializing VGA ROM.
> >
> > You could always try Debugging the Unexpected Exception errors with GDB,
> > this may give you a clue on what the problem is.
> >
> > http://www.coreboot.org/Debugging
>
> Actually i tried GDB and failed to build the image.. I got  section
> overlap error and was not able to solve it.
>
> What i didnt understand is
>
> Why coreboot can't run a VGA ROM which seabios can?
> What is the big difference while executing VGA ROM in coreboot and
> seabios?
>
> From the log you can see seabios emits some warning messages(fail
> handle_155fXX) but still it continues to run the VGA ROM, where x86emu or
> realmode hangs with error messages
>
> in seabios
> fail handle_155fXX:23(86):
>
> a=a0005f38  b=000008c1  c=00000003  d=0000c000 ds=a000 es=c000 ss=a000
>
> si=00000000 di=00000003 bp=000077cc sp=000077be cs=c000 ip=3115  f=0002
>
> Real mode
>
> Real mode stub @00000500: 422 bytes
>
> Calling Option ROM...
>
> oprom: INT# 0x8e41a854
>
> oprom: eax: 8a000885 ebx: 0e21e039 ecx: 00028101 edx: 2989b606
>
> oprom: ebp: 58000a58 esp: c0010004 edi: c668404c esi: c2650304
>
> oprom:  ip: e6b0      cs: 8831   flags: 00002900
>
> Unexpected Exception: 6 @ 10:f6fdd07d - Halting
>
> Code: 0 eflags: 00010012
>
> eax: 00007776 ebx: 00008831 ecx: 0010ef73 edx: 001059b1
>
> edi: c0010004 esi: 8e41a854 ebp: 00002900 esp: 0000774a

well lets see,
The coreboot rom emulators are completely different beasts than seabios.
Perhaps you take a look at the differences in the interrupt handlers to
find out the differences?

I would suggest running YABEL in full DEBUG mode, YABEL is able to output
rom PCI accesses, io accesses, interrupt calls etc. I would also suggest if
you do this to output your bootlog to a text file in minicom, because it
may run for several hours and get quite large. I would be glad to take a
look at it and see if I can see what is going on.