Grub-legacy graphics issue

[jnqnfe <jnqnfe@gmail.com>]

I am having some graphics issues using grub-legacy, and I'm struggling
to find an answer.

I am currently working on fixing various bootloader issues with Debian
live images generated by the live-build tool (the full list of which can
be found in bug #775322 if you're interested). Today I have managed to
come up with patches for fixing splash loading and other display issues
for grub2, but I'm having trouble with grub-legacy.

Booting the image in a virtualbox VM, grub-legacy displays the boot menu
in what appears to be a 640x480 sized window, however the graphics are
very poor. The default splash is a black image with a yellow
construction worker helmet. What I am seeing is a background of
alternating yellow and grey/black 1px vertical lines, and a blurry
multi-coloured helmet. Multi-line output, e.g. by the vbeprobe is very
slow, taking a couple of seconds per refresh of the output, so taking
several moments to output the list.

I am guessing that the graphics are not in the correct mode.

The menu.lst config file, ignoring the menu entries (which only set
kernel details and menu entry titles), only specifies the following:

default 0
color cyan/blue white/blue
splashimage /boot/grub/splash.xpm.gz

>From within command mode of the running copy of grub-legacy I have tried
setting 'terminal graphics', which did nothing, and I have tried
'testvbe 0x143' (since 800x600x32 mode worked perfectly for me with a
grub2 based image in the same VM), which just results in a load of
flashing colour gradients, and upon that ending, dumps me at a black
screen with a grey underscore character in the top left, where I can't
seem to do anything (typed text does not appear), but playing around I
can eventually get back to the menu as it was before.

So, grub-legacy gurus, how do I fix this?

(Please cc me, I don't subscribe to this mailing list).