[coreboot] Need help with VGA on epia-m

bari bari at onelabs.com
Mon May 26 18:30:24 CEST 2008

The Epia-CN (C7+cn700+vt8237r) is having the exact same issue even 
though it is using a more recent VIA chipset. Epia-M9000 (C3 + CLE266 + 
vt8235). This lack of Console VGA issue was next on the list after I 
clear up some IRQ issues with the CN.

What are we missing for VIA chipsets with integrated video to bring up 
Console VGA?

Config.lb in targets/via/epia-cn has:

cat vgabios bochsbios coreboot.rom > coreboot.rom.final
option ROM_SIZE=512*1024 - 64*1024 - 64*1024

Yet I get the same results with VGA if BOCHS is not included. BOCHS does 
not seem to have an effect on X sever and VGA.

cat vgabios coreboot.rom > coreboot.rom.final
option ROM_SIZE=512*1024 - 64*1024


Kevin O'Connor wrote:
> Hi,
> I've been trying to boot my epia-m9000 with coreboot-v2 (rev 3348) and
> filo-0.5 (rev 48).
> I can not get the normal Linux VGA text console to work.  I also don't
> see any VGA output from filo, nor via int 0x10 calls if I use
> "legacybios" as a payload.  The monitor attached seems to think there
> is no signal present at all.
> Interestingly, the machine boots into the OS with no problems.  The
> hard drive has Fedora Core 9 installed on it.  I instructed filo to
> use the FC9 grub file (MENULST_FILE = "hda1:/grub/grub.conf").  I was
> very impressed at how filo was able to boot the system seamlessly once
> it was given the grub config file.
> Ironically, I can even start the X server, and get vga output with
> it.  However, I still don't get VGA text output if I switch between
> the X server and a text console.
> Here is what I did to get to this point.
> * Use coreboot-v2 (rev 3348)
> * Obtain the VGA option rom pci1106,3122.rom from:
>   http://www.coreboot.org/viewvc/trunk/optionroms/?root=optionroms
> * Change targets/via/epia-m/Config.lb to only have a single "fallback"
>   image, and make enough room in the rom for the VGA bios.
>   Specifically I changed lines to:
> option ROM_SIZE=256*1024 - 57344
> buildrom ./coreboot.rom ROM_SIZE "fallback"
> * After every build, prepend the vga bios to the coreboot.rom to make
>   the full 256KiB rom:
>   cat pci1106,3122.rom coreboot.rom > coreboot.final.rom
> Again, the X server works, but I don't get normal bootup VGA text
> output.  I've tried many different combinations with the vga bios
> without luck (using dd to extract vga bios, padding OptionsRom bios to
> 64K, adding explicit pci entry to mainboard Config.lb).
> It's clear that the vga bios is running - the logs show lots of
> interaction with int15.
> Any ideas?

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