Cleanup a20 code.

Fix two apparent bugs - set_a20() returned new status instead of old
    status and handle_152402() checked wrong bit.
Add bit definition for the a20 enable bit: A20_ENABLE_BIT
Allow ioport.h #defines to be used in romlayout.S.
4 files changed
tree: fe2d6c446ef22c1d0d51b6828d20dd6f9ea12b9f
  1. .gitignore
  2. COPYING
  3. Makefile
  4. README
  5. TODO
  6. src/
  7. tools/