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

Luc Verhaegen. libv at skynet.be
Sat Mar 17 15:39:40 CET 2007

On Sat, Mar 17, 2007 at 03:03:37PM +0100, Stefan Reinauer wrote:
> * Luc Verhaegen. <libv at skynet.be> [070317 14:04]:
> > > I want it to go into a nice picture/or solid color
> > > within less a second after press the ON button.
> > 
> > Yes, people do seem to want to have a pretty bootsplash. This 
> > possibility will be given.
> I remember we had some bootsplash in LinuxBIOSv1, but it was never
> ported over. 
> There's two things that are potentially time consuming in hw startup:
> * dram init (ie. on large machines)
> * compression (on small machines)
> In LinuxBIOSv2 the code that does PCI init (and thus initializes the
> graphics hardware) is compressed if CONFIG_COMPRESS is set. This means
> time is wasted before there is any chance to actually init VGA and show
> a splash screen.
> In v3 we completely dropped the VGA console code (NOT the VGA init
> code!) and leave everything graphical or textual to the payload.
> LinuxBIOS _console_ will only be on serial or usb debug. This makes the
> code smaller and the bootup look a lot nicer. VGA output is of no use
> for debugging because the critical stuff in LinuxBIOS happens before 
> we have it.
> Stefan

Are you saying there that, for the likes of filo, grub, etherboot, etc 
will be forced to set up a full VGA console themselves? Or are you for 
forcing everybody to use a serial console to:
* instruct the bootloader on what to do, what kernel to load from where.
* manually fsck your root filesystem after a bad reboot.
* or in the most insane case: alter your X setup when X gives up?

I'm sure that there are tons of examples here.

What the unichrome needs for getting a VGA text console will well make 
up for the space taken by the VGA ROM. And if it wasn't for the font, 
then this would all take less space than the code used currently in 
northbridge/via/vt8236/ that's used for running the VGA BIOS.

I understand that this is all happening too late for debugging 
linuxbios, but this isn't about debugging linuxbios. For me it is about 
being able to do something useful when it jumps to the bootloader or the 
kernel. When you force everybody to have serial for this, linuxbios will 
not be accepted by the masses, even when their full board is directly 

Now i'm not overly keen on spending time on a bootsplash myself, it is 
something everyone can quite easily live without. But in previous 
conversations i don't remember you being negative towards it :)

I fully understand that you want to push this as far down the linuxbios 
line as possible. But it would be nice if linuxbios presented a working 
vga console to the actual payload. Setting up VGA and loading the font 
could of course be delayed until right before the actual payload. At 
which time it should be easy to tell users that they have been using 
linuxbios :)

Luc Verhaegen.

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