Re: vga16fb: blank screen with Intel GM965/GL960 on HP 2510p notebook

[Geert Uytterhoeven <geert@linux-m68k.org>]

On Sun, 23 Mar 2008, Frans Pop wrote:
> The problem here is that /proc/fb doesn't show VESA when the regular 
> installer is booted, AFAICT because we boot with vga=normal. vesafb seems 
> to only be actually activated by the kernel during boot if you boot with a 
> vga mode that requires it.

That's true. Vesafb uses the linear graphics mode as programmed by the
BIOS _before_ starting the kernel, and doesn't contain code to switch graphics
mode itselfs.

> The installer then runs its init scripts, specifically
> /lib/debian-installer-startup.d/S40framebuffer-module-linux-x86, and that 
> ends up loading vga16fb because loading vesafb fails (as it's compiled in).
> And thus you end up with vga16fb, basically because it's the only 
> framebuffer available _despite_ the fact that vesafb is compiled in...
> 
> Is there is a way to activate vesafb post-boot even when the system was 
> booted with vga=normal? If there is this could probably be avoided.

No, as it relies on the BIOS.

Uvesafb can, but it relies on a userspace helper daemon.

> Also, does anyone know a way to test whether fbcon is compiled in or not?
> We can of course test if fbcon is available as a module and assume it's 
> compiled in if not, but that's not a proper test that it _is_ present.

If /sys/class/graphics/fbcon exists but lsmod doesn't show fbcon?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

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