[Craneboard] how to show anything on DVI display

Can anybody tell how to configure Craneboard to show anything on a DVI
display? I've compiled kernel using instructions from here:
http://processors.wiki.ti.com/index.php/Building_images_for_CraneBoard
and a display turns blank during boot but remains active. I suppose I
need to set some arguments in bootargs but the crane-uboot does not
contain any default arguments sufficient to turn the display on.

BTW the strangest thing is that I turned on the Penguin logo during
kernel boot and it did not appear..

Please assist.

Max