vesafb console scrollback

[Neale Banks <neale@lowendale.com.au>]

Greetings all,

I've been scrounging around the source looking for clues in relation to
a minor but annoying anomally with vesafb (at least with a 128x48[1] fb
console under linux 2.2) and console scrollback - and just can't get a
handle on this.

The anomally is that when the logo is displayed at boot time (i.e. the
Tux in the top left) console scrollback doesn't work quite correctly[2].
Anything that makes Tux disappear also makes this anomally go away.

The bits of code I am (so far unsuccesfully) looking for include:

* basic scrollback (i.e. shift-PgUp)

* the logic/variables that deal with if the logo is displayed (and
  presumably that the console is a few lines smaller).

The code I've loked through so far includes linux/drivers/video
(specifically vesafb.c and fbcon.c) - but something just didn't click
here {:-(

Any hints/pointers/etc gratefully accepted.

Thanks,
Neale.


[1] To be more accurate:
vesafb: framebuffer at 0xfc000000, mapped to 0xcf000000, size 16384k
vesafb: mode is 1024x768x16, linelength=2048, pages=9
vesafb: protected mode interface info at c000:77f8
vesafb: scrolling: redraw
vesafb: directcolor: size=0:5:6:5, shift=0:11:5:0
Console: switching to colour frame buffer device 128x48
fb0: VESA VGA frame buffer device

[2] It's quite "odd" - some characters get left behind.  I haven't been
able to identify any patterns in the particular character positions, but
it is consistent (i.e. with each boot the same characters get left
behind on initial scrollback).

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