global gets 

section .text
gets:
	push	rbp
	mov	rbp,rsp

	push	rbx
	push	rcx
	push	rdx
	push	rsi
	push	rdi

	mov	rax,3		; sys_read
	mov	rbx,1		; stdin
	mov	rcx,[rbp+16]	; buffer
	mov	rdx,4 		; buffer_size
	int	0x80

	xor	bl,bl
	xor	ax,ax
	xor	rcx,rcx
	xor	rdx,rdx

	mov	cx,4
	mov	rdi,[rbp+16]
strtobin:	
	mov	al, byte [rdi+rcx-1]
	cmp	al, 0xa
	je	loend	
	cmp	al, 'A'
	jl	digit
	cmp	al, 'F'
	jg	ferror	
	sub	al, 'A'-10
	jmp	addd
digit:	
	cmp 	al, '0'
	jl	ferror
	cmp	al, '9'
	jg	ferror
	sub	al, '0'	
addd:	
	mov	si, cx
	mov	cl, bl
	shl	ax, cl
	mov	cx, si

	add	bl, 4
	add	dx, ax
loend:		
	loop	strtobin	
	mov	rax,[rbp+24]
	mov	[rax],dx
	mov	rax, 0
	jmp	fend
ferror:
	mov	rax, 1
fend:	
	pop	rdi
	pop	rsi
	pop	rdx
	pop	rcx
	pop	rbx
	pop	rbp
	ret	16