vern@2007-03-06:/var% ls tags

video=vesa:option[,options]

FROM: http://lists.debian.org/debian-user-spanish/2003/12/msg00433.html

Accepted options:

invers  no comment...

ypan    enable display panning using the VESA protected mode  
    interface.  The visible screen is just a window of the
    video memory, console scrolling is done by changing the
    start of the window.
    pro:    * scrolling (fullscreen) is fast, because there is
          no need to copy around data. 
        * You'll get scrollback (the Shift-PgUp thing),
          the video memory can be used as scrollback buffer
    kontra: * scrolling only parts of the screen causes some
          ugly flicker effects (boot logo flickers for 
          example).

ywrap   Same as ypan, but assumes your gfx board can wrap-around 
    the video memory (i.e. starts reading from top if it
    reaches the end of video memory).  Faster than ypan.

redraw  scroll by redrawing the affected part of the screen, this 
    is the safe (and slow) default.

vgapal  Use the standard vga registers for palette changes.
    This is the default.
pmipal  Use the protected mode interface for palette changes.

mtrr    setup memory type range registers for the vesafb framebuffer. 

vram:n  remap 'n' MiB of video RAM. If 0 or not specified, remap memory
        according to video mode. (2.5.66 patch/idea by Antonino Daplas
    reversed to give override possibility (allocate more fb memory 
    than the kernel would) to 2.4 by tmb@iki.fi)