show framebuffer console modes to use in grub vga option

look at /boot/grub/menu.lst for somethig like:

## additional options to use with the default boot option, but not with the

## alternatives

## e.g. defoptions=vga=791 resume=/dev/hda5

## defoptions=vga=795

# defoptions=vga=873

## altoption boot targets option

## multiple altoptions lines are allowed

## e.g. altoptions=(extra menu suffix) extra boot options

## altoptions=(recovery) single

# altoptions=(verbose mode) vga=775 debug

# altoptions=(console mode) vga=ask

# altoptions=(graphic mode) quiet splash

# altoptions=(recovery mode) single

vga=(decimal value) is framebuffer mode