OS Dev

• Resources
  • University of Utah CS5…
  • osdev
• Steps:
  • install a cross compiler
  • use freestanding flag (to make code os independent; e.g. mallocs, …)
  • simulator:
    • qemu: no debugging support
    • boch: has good debuggin support.

• Real Mode: Can use BIOS functions but can use only 1MB
• Protected Mode: Now has access to 32 bit memory but can't use BIOS
• Extended Mode: Now has access to 64 bit memory but can't use BIOS