Re: [Nasm-users] can't write argv[0] on stdout

[Holger H. <ha...@gm...>]

On Tue, 18 Aug 2009 23:33:46 -0700
"H. Peter Anvin" <hp...@zy...> wrote:

> On 08/18/2009 07:34 AM, Holger Hanrath wrote:
> > Hi all,
> > 
> > i want to write 3 bytes of argv[0] on stdout but it doesn't work. 
> > Return code -14 (EFAULT Bad address). Am i missing something here? 
> > 
> > System is archlinux 2009.08 x86_64 kernel 2.6.31-rc6 
> > nasm 2.05.01 Binutils 2.19.1.20090418
> > 
> > 
> > 
> > stdout	equ	1
> > write	equ	4
> > exit	equ	1
> > 
> > section .text
> > 	global	_start
> > _start:	
> > 	pop	rax		; rax = argc
> > 	pop	rax		; rax = argv[0]
> > 
> > 	mov	rdx,	3	; write 3 bytes
> > 	mov	rcx,	rax	; rcx = rax = argv[0]
> > 	mov	rbx,	stdout	
> > 	mov	rax,	write	
> > 	int	0x80
> > 	
> > 	mov	rbx,	0
> > 	mov	rax,	exit
> > 	int	0x80
> > 
> 
> int 0x80 is used for 32-bit system calls.  64 bits uses syscall, and
> entirely different system call numbers and a different calling convention.

i see that now thanks for pointing out

Holger