http://git.dujemihanovic.i2p?p=nameless-os.git;a=blob;f=boot/x86/a20.s;h=f6a292ba6bd23bbf2e24564b1351d530836930ae;hb=f6a292ba6bd23bbf2e24564b1351d530836930ae
search: re f6a292ba6bd23bbf2e24564b1351d530836930ae [nameless-os.git] / boot / x86 / a20.s 1 ; Some routines for managing the A20 line 2 3 ; Check if A20 is enabled 4 ; Based on <https://wiki.osdev.org/A20_Line#Testing_the_A20_line>, slightly modified 5 check_a20 6 pushf ; save EFLAGS 7 ; save segment and index registers 8 push ds 9 push es 10 push di 11 push si 12 13 cli ; disable interrupts 14 xor ax, ax ; ax = 0 15 mov es, ax ; es = 0 16 17 not ax ; ax = FFFFh 18 mov ds, ax ; ds = FFFFh 19 20 mov di,...