32bit.asm

来自「可在Intel x86上执行的最小OS,完全用组语撰写 可做DISK IO,P」· 汇编 代码 · 共 33 行

[BITS 32]
	align 4
Begin32c:
	mov ax, kernel_data - _GDT
	mov ds, ax
	mov es, ax
	mov fs, ax
	mov gs, ax
	mov ss, ax
	mov esp, 0x2FFFF

	call TestMemory

	mov edi, memMap		;
	mov ecx, 0x100 / 32
	xor eax, eax
	dec eax
	rep stosd

	mov ecx, 0x20000 / 4 - (0x100 / 32)	;
	xor eax,eax
	rep stosd

	; timer set to 1/100 s
	mov al, 0x34	; set to 100Hz
	out 0x43, al
	mov al, 0x9b	; lsb 1193180 / 1193
	out 0x40, al
	mov al, 0x2e	; msb
	out 0x40, al

	call EnableIRQs