PC bootsector string spewer in NASM

pcbooter.s

; vi:ft=nasm

cpu 8086
org 0x0

	jmp start
	rulz db 'seg rulz ok ',0

start:	cli ; disable interrupts because lolbugs
	mov ax,0x7c0 ; BIOS loads code at 0000:7C00
	mov ds,ax
	mov es,ax
	; set up stack
	xor ax,ax
	mov ss,ax
	mov sp,0xffff
	sti

	xor	bx,bx	; attrib
	mov	cx,1	; just one thanks

.again:	inc	bx	; next attrib
	and	bl,0x7F	; no flashing please
	mov	si,rulz

.loop:	lodsb 		; load next char
	test	al,al
	jz	.again

	mov	ah,09h	; write char with attrib
	int	10h	; BIOS
	mov	ah,0Eh	; write char and advance
	int	10h	; BIOS
	jmp	.loop

times 510-($-$$) db 0
	dw 0xAA55