33 lines
606 B
NASM
33 lines
606 B
NASM
|
SECTION .text
|
||
|
|
USE16
|
||
|
|
;Generate a memory map at 0x500 to 0x5000 (available memory not used for kernel or bootloader)
|
||
|
|
memory_map:
|
||
|
|
.start equ 0x0500
|
||
|
|
.end equ 0x5000
|
||
|
|
.length equ .end - .start
|
||
|
|
|
||
|
|
xor eax, eax
|
||
|
|
mov di, .start
|
||
|
|
mov ecx, .length / 4 ; moving 4 Bytes at once
|
||
|
|
cld
|
||
|
|
rep stosd
|
||
|
|
|
||
|
|
mov di, .start
|
||
|
|
mov edx, 0x534D4150
|
||
|
|
xor ebx, ebx
|
||
|
|
.lp:
|
||
|
|
mov eax, 0xE820
|
||
|
|
mov ecx, 24
|
||
|
|
|
||
|
|
int 0x15
|
||
|
|
jc .done ; Error or finished
|
||
|
|
|
||
|
|
cmp ebx, 0
|
||
|
|
je .done ; Finished
|
||
|
|
|
||
|
|
add di, 24
|
||
|
|
cmp di, .end
|
||
|
|
jb .lp ; Still have buffer space
|
||
|
|
.done:
|
||
|
|
ret
|