[coreboot] VGA doesn't work on Mohon Peak

[Kevin O'Connor]

Just to be clear, it's fine to try initializing the video card in
SeaBIOS, it's fine to try initializing the video card in coreboot, and
it's fine to try and hold off initialization until Linux starts.  But,
definitely don't try booting with two or more points trying to
initialize the video hardware - that's known to cause problems.

When attempting to initialize the video hardware in SeaBIOS, make sure
coreboot has CONFIG_VGA_ROM_RUN, CONFIG_ON_DEVICE_ROM_RUN,
CONFIG_VGA_BIOS, and CONFIG_PXE_ROM all disabled.  If attempting to
initialize the video in coreboot or Linux, then one must force SeaBIOS
to not attempt to run the vga option rom - the easiest way to do this
is to use the latest development seabios code and set
/etc/pci-optionrom-exec to 0 (see
http://www.coreboot.org/SeaBIOS#Other_Configuration_items ).

-Kevin


On Sun, Mar 22, 2015 at 05:32:32PM +0000, ron minnich wrote:
> A good first pass is to enable YABEL instead of native execution and watch
> what it does. That's how I've had to debug graphics before.
> 
> Also, if you can do a serial console only setup, you can run the VBIOS once
> linux is booted and try to debug it that way.
> 
> It's very hard to debug a VBIOS issue as you are doing it now, however. It
> will take years off of your life :-)
> 
> ron
> 
> On Sun, Mar 22, 2015 at 9:07 AM Martin Roth <gaumless at gmail.com> wrote:
> 
> > 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 <kevin at koconnor.net>
> > 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
> >>
> >> --
> >> coreboot mailing list: coreboot at coreboot.org
> >> http://www.coreboot.org/mailman/listinfo/coreboot
> >>
> >
> > --
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