[ORG	0x0000]
[BITS	16]


%define	LOADADDR				  0x7C00

%define Bugged_Version
%define Functionnal_Version

%ifdef Bugged_Version
  %define	laddr(x)				(LOADADDR + x)
%elifdef Functionnal_Version
  %define	laddr(x)				(0x5C00 + x)
%endif
		
		
_start:
		cli						; disable interrupt
		xor ax, ax			; clean AX
		xor bx, bx			; clean BX
		xor cx, cx			; clean CX
		xor dx, dx			; clean DX
		mov ds, ax				; clean DS
		mov es, ax				; clean ES
		mov fs, ax				; clean FS
		mov gs, ax				; clean GS
		mov si, ax			; clean SI
		mov di, ax			; clean DI
		mov ss, ax				; set up stack
		mov sp, LOADADDR		; SS:SP -> 0x0:0x7C00
		mov bp, ax				; clean BP
		sti
		cld
		
		mov ax, cs
		call _put_nb
		mov si, laddr(_lf)
		call _put
		call _addr
		
		mov si, laddr(_hy_man)
		call _put
		mov si, laddr(_lf)
		call _put
		
_loop:
		jmp short _loop



_addr:
		push bp
		mov bp, sp
		add bp, 2
		mov ax, [ss:bp]
		mov cx, 0x10
		call _put_nb
		mov si, laddr(_lf)
		call _put
		pop bp
		ret
			
_hy_man:db 'Hello World', 0x0
_lf:	db 0xA, 0x0


_put:
				pusha					; don't trust the BIOS
		.get_cursor:
				; mov AH, 0x3				; Place dans AH le numéro de fonction.
				; xor BX, BX				; RAZ de BX qui contient la page d'affichage.
				; int 0x10				; Appele de l'interrupteur 0x10
				xor dx, dx
				xor ax, ax
				mov al,  [0x0462]		; page number
				mov cx, 2
				mul cx
				add ax, 0x450			; AX -> cursor position address
				xchg ax, bx
				mov dl, [es:bx]			; DL = column
				mov dh, [es:bx+1]			; DH = row
				xor bx, bx
				mov bh, [0x0462]		; page number
				mov CX, 0X1				; CX contient le nombre d'affichage de chaque caractère
		.write_char:
				lodsb	
				or AL, AL	
				jz short .end	
				cmp AL, 0xA	
				jz short .inc_line	
				pusha
				mov AH, 0xA	
				int 0x10
				popa
				inc DL	
		.set_cursor:
				pusha
				mov AH, 0x2		
				int 0x10	
				popa
				jmp short .write_char
		.inc_line:
				inc DH					
				xor DL, DL				
				jmp short .set_cursor	
		.end:
				popa					; Restauration des registres
				ret
_put_end:

_put_nb:
; IN:	AX = N
;		CX = Base
			push bp
			push word 0x0
			mov bp, sp
			sub sp, 32
	.div:
			dec bp
			xor dx, dx
			div cx
			cmp dx, 10
			jge short .alpha_digit
			add dl, 0x30
			jmp short .push_digit
	.alpha_digit:
			add dl, 0x37
	.push_digit:
			mov byte [ds:bp], dl
			or ax, ax
			jz short .print
			jmp short .div
	.print:
			mov si, bp
			call _put
			add sp, 34
			pop bp
			ret
_put_nb_end:


times 0x1FE-($-$$)	db 0x00
					dw 0xAA55