[LinuxBIOS] linuxbios + xf86-video-unichrome: no VGA BIOS needed.

Luc Verhaegen. libv at skynet.be
Sun Mar 18 03:42:16 CET 2007

On Sat, Mar 17, 2007 at 04:29:50PM +0100, Stefan Reinauer wrote:
> * Luc Verhaegen. <libv at skynet.be> [070317 15:39]:
> > Are you saying there that, for the likes of filo, grub, etherboot, etc 
> > will be forced to set up a full VGA console themselves? 
> Not more than at the moment. You need functions that write characters to
> 0xb8000, more or less. But you need them in v2 as well. LinuxBIOSv2 does
> not provide a library or anything for console output.

Right, but we do need to provide a working mode, with dac and fonts 

> Noooo! ;-) No worries. This is only for everything up to loading the
> payload. The bootloader (payload) will be able to use an initialized
> VGA console (and, eventually find out via the linuxbios table whether it
> is text mode or framebuffer and what address and resolution it is?)

Ah, right :)
> The idea is just to hide the _LinuxBIOS_ _debug_ messages from VGA
> console, as it is too late for debugging. In my tests FILO would
> immediately start printing the grub menu in text mode, but that is the
> first thing you will see, after a fraction of a second.

Ah, of course, this intention clearly was lost on me :) Yes, this is all 
very sensible indeed.

> It is one thing I found out during the last few days, starting to work
> on vm86/x86emu: In v3 we are so fast again that the need of a bootsplash
> during _LinuxBIOS_ execution might not exist. Maybe the payload should
> do this, or the CMOS setup menu (to be shown while waiting for the
> keypress timeout), that some people talked about,.. or....
> I am not at all negative. I am just thinking out loud where stuff is
> done best.

Ah, you talked about a possible bootsplash _last_ week :)
> It does this, but in v3, it will not use it anymore for printing "all
> devices initialized. looking for payload. etc pp".

> Well, v3 currently knows how to init the VGA console by executing an
> option rom, but we will be changing this soon, I hope (for instance when
> bringing the Epia port over)

Well, i'll soon have rudimentary VGA modesetting + font loading working 
in a userspace app, that, when ported over, will hopefully get every 
VGA compatible device a working console quickly and easily. Well, when 
the hardware gets initialised far enough to allow that.

Luc Verhaegen.

More information about the coreboot mailing list