# strlen
#
# gcc xstrlen.s -o xstrlen
#
# $ ./xstrlen foobar
#
	
.section .data
	.equ LINUX_SYSCALL, 0x80
	.equ SYS_EXIT, 1

output:
	.asciz "%d\n"

debug:
	.asciz ":%s:\n"
	
.section .text
	.globl main

main:
	movl 8(%esp), %eax
	movl 4(%eax), %eax
	
	pushl %eax
	call strlen
	addl $4, %esp	
	
	pushl %eax
	pushl $output
	call printf
	addl $8, %esp
	
	movl $0, %ebx
	movl $SYS_EXIT, %eax
	int $LINUX_SYSCALL

strlen:
	pushl %ebp
	movl %esp, %ebp
	movl $0, %ebx
	movl 8(%ebp), %eax
	pushl %eax
	
strlen_loop:
	movl (%esp), %eax
	addl %ebx, %eax
	cmpb $0, (%eax)
	je strlen_end
	addl $1, %ebx
	jmp strlen_loop

strlen_end:
	movl %ebx, %eax
	movl %ebp, %esp
	popl %ebp
	ret