vgabios: Split vgafb_scroll() into separate move and clear functions.

Rewrite the low-level scroll code so that it is implemented using two
basic operations: move text and clear text.  This simplifies the
low-level code as it no longer needs to handle up scrolling vs down
scrolling.  Determining the direction of the scroll is now done in the
higher level (vgabios.c) code.

Signed-off-by: Kevin O'Connor <>
3 files changed