[nSLUG] Problems with console text

Jack Warkentin jwark at bellaliant.net
Tue Jun 4 16:49:47 ADT 2013

Hi Mike

A couple of other related documents to read would be fb/vesafb.txt.gz 
and svga.txt.gz, both in the Documentation directory hierarchy (at least 
that's where they are on my Debian system).

First of all, there must be no spaces around the "=" sign in the 
vga=<mode> parameter.

Second, if this parameter is omitted entirely, you won't enter 
framebuffer mode until the video card's driver is loaded, further along 
in the boot process. In that case, I *believe* you will get large fonts 
on the console, like what those old 14" 640X480 terminals had.

Third, AFAIK, people use vga=791 (for example) to get smaller, but not 
tiny, fonts on their consoles. I use vga=0x3E3 and that works well for 
me on my 24" 1920x1200 screen.

I also ascertained that the fbcon=<options> that can be included on the 
kernel boot command line only apply to the vesa framebuffer created very 
early in the boot process by the vga=<mode> parameter. Once the video 
card's driver is loaded, and that driver's framebuffer is started, the 
fbcon=<options> from the kernel boot command line no longer apply. To 
get around this problem, the video card's driver module must be compiled 
right into the kernel, instead of being loaded as a module later in the 
boot process, in which case the fbcon=<options> will apply as long as 
the system is not rebooted.

If you don't want a framebuffer at all ever, you need to recompile the 
kernel, omitting the fbcon module. If fbcon is compiled into the kernel, 
you will get the video card driver's framebuffer as soon as that driver 
module is loaded, whether you want it or not.

The above is my understanding and I hope it helps. If I am wrong I would 
very much like to be corrected, because I have struggled with these 
sorts of problems off and on for years.



Mike Spencer wrote:
> My son dropped off his new/used laptop for consultation.  He's ++good
> with Windoes but a Linux novice.  I solved some problems for him but I'm
> stumped by one:
>      He mistakenly chose the wrong option at install time and now has
>      consoles with teeny-tiny text. ([VESA?] frame buffer mode?)  I don't
>      know how to revert it to the default, much larger, console text.
>      His lilo.conf has "vga = normal" and I re-ran lilo.  Still comes
>      up with teeny text.
>      cat /sys/devices/virtual/vtconsole/vtcon0/name
>      (S) VGA+
>      cat /sys/devices/virtual/vtconsole/vtcon0/name
>      (M) frame buffer device
>      There *must* be a way to fix this short of re-installing
>      Slackware.
>      Yes, I've read:
>        /usr/src/linux-3.2.29/Documentation/fb/fbcon.txt
>      Is that the only way to do this?  I don't want to switch back and
>      forth.  I just want his box to boot into plain VGA console.
> FWIW, this is an eMachines 64-bit AMD laptop with Slack 14 and KDE
> installed. Son uses KDE because he's used to the Win environment.
> (I'm reminded how very much I hate GUI desktops.)
> I'm hoping to be at the meet on Monday, LWATCDR.
> - Mike

Jack Warkentin, phone 902-404-0457, email jwark at bellaliant.net
39 Inverness Avenue, Halifax, Nova Scotia, Canada, B3P 1X6

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