Re: [coreboot] VGA doesn't work on Mohon Peak

[Martin Roth]

My experience is that the aspeed chip based graphics card that comes with
Mohon Peak has a bug in the vbios causing it to hang when run.  If you need
to use this specific card, you'll need to debug it, probably with a jtag
debugger, going through the assembly, and see what's causing the issue.  My
initial guess is that they're looking for some value in the bda or ebda
that isn't present, but I'm not sure what this might be.

Martin

On Sun, Mar 22, 2015 at 8:45 AM, Kevin O'Connor  wrote:
> On Fri, Mar 20, 2015 at 12:30:38PM +0300, Kuzmichev Viktor wrote:
> > I tried not to include any VBIOS file in coreboot ROM much earlier, in my
> > first tests. With 'Run VGA Option ROMs' option checked the board just
>
> hung.
> > And as I mentioned in my previous email VGA works fine with vendor's
>
> BIOS.
> > So the card itself should be fine.
> >
> > Sadly, I don't have another card to try. Even if I had, I still would
>
> need
> > to make this one work somehow as Mohon Peak is just a reference board and
> > the target board will have a similar VGA controller.
> >
> > So please, let me know if there are some other things I could try or if
>
> I am
> > mistaken somewhere.
>
> Hi Viktor,
>
> It seems you've tried a bunch of different configurations.  However,
> this is making your trouble report hard to understand as it becomes
> unclear which config had which results.
>
> If you have an external VGA card, then please build coreboot with
> CONFIG_VGA_ROM_RUN, CONFIG_ON_DEVICE_ROM_RUN, CONFIG_VGA_BIOS, and
> CONFIG_PXE_ROM all disabled.  Please use either the SeaBIOS provided
> by coreboot, or build SeaBIOS with a default config (only
> CONFIG_COREBOOT and if needed CONFIG_DEBUG_SERIAL changed from the
> seabios defaults).  This is described at:
> http://www.coreboot.org/SeaBIOS
>
> In particular, there should be no "pciXXXX,YYYY.rom" or "vgaroms/XXX"
> files in your cbfs rom.
>
> If the above does not work, please use the above config and recompile
> SeaBIOS at debug level 8, and post the full debug log along with the
> output of "cbfstool print".
>
> Cheers,
> -Kevin