[SeaBIOS] [PATCH] src/bootsplash.c: Fix displaying VGA bootsplash

Kevin O'Connor kevin at koconnor.net
Tue Feb 14 14:40:20 CET 2012

On Tue, Feb 14, 2012 at 06:37:18AM +0100, Gerhard Wiesinger wrote:
> On Mon, 13 Feb 2012, Kevin O'Connor wrote:
> >On Mon, Feb 13, 2012 at 07:42:52AM +0100, Gerhard Wiesinger wrote:
> >>VGA bootsplash isn't displayed because video mode is set
> >>which clears the display. Video mode has already been set
> >>by the VGA BIOS.
> >
> >The experience from running on real hardware has indicated that a real
> >off-the-shelf BIOS will init the display and clear the screen at
> >startup.  We've seen real off-the-shelf vgabios do weird things if the
> >BIOS doesn't init and clear the screen.
> But on real hardware one CAN SEE init string display of e.g. NVIDIA
> and AMD cards (some do also a beep after VGA display or on BIOS
> init). Also screen is cleared afterwards. Maybe there is a short
> delay in VGA BIOS/BIOS.

This would be for the vgabios to do.  I certainly wouldn't encourage
it though, as I don't much like boot delays.

> Another possibility would be to add it as option in the build
> process. I've already defined an #ifdef therefore.
> Maybe an optional delay (config option) before setting video mode
> would also be fine.

I would really prefer to have one code path for all platforms.  I
don't see much value in seeing the vgabios screen - certainly not
enough to add delays to the boot.


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