Re: prompt falls out of the screen

[Danilo Segan]

Today at 13:50, sigbj-st <sigbj-st@frisurf.no> wrote:

> I have a problem with one of my pc-machines that the prompt often
> falls below the screen when loading the Hurd. The letters get to
> big. 
>
> In linux I can just on boot enter vga=791 or 794 on the Lilo-prompt
> and that gives me smaller screenletters. 

Linux has some (ugly, if I may say :) hacks to make use of VESA BIOS
Extensions 2 (VBE2) when you request such high graphics modes.  If I
remember correctly, you have to be in real mode (as compared to
protected mode, in which rest of the operating system runs) in order
to be able to switch to a higher video mode (call "int 10h") and set
up VBE2 framebuffer.  That's why Linux has to know that at boot time,
even before it switches to protected mode.

Linux also offers proper framebuffers which depend on graphics
hardware itself (commonly available as kernel modules), where you can
use fbset to change modes in runtime.

> How I do this while grub is loading I do not know.
> Any suggestion out there?

I believe you need to hack on GNU Mach to add such support yourself.
I.e. the answer to your question is probably *you can't*.

OTOH, there're other video modes which are probably supported on GNU
Mach itself, such as 80x50, even though they use the same image width
and height in pixels (aka "resolution", 640x400 for VGA text modes I
think), only smaller glyphs (8x8 vs. 8x16), making them look shitty.
I don't know how to activate them—perhaps someone else can chip in
with some tips?

Cheers,
Danilo