vgabios: Framebuffer fixes for CGA and planar graphics modes.

Fix missing divide by 2 in CGA mode scroll.  Consistently use
cheight/2 for all uses.

Planar graphics character write has a read to video memory with a side
effect - mark that as volatile so the compiler doesn't optimize it
away.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
1 file changed
tree: 41889ca152166985f32c6d25fee1ee8b4a5cb574
  1. src/
  2. tools/
  3. vgasrc/
  4. .gitignore
  5. COPYING
  6. COPYING.LESSER
  7. Makefile
  8. README
  9. TODO