hello_2.asm

;; hello_2.asm ;;
;; prints 5 strings 'hello' with one syscall ;;

global _start				;should ALWAYS be global, or ld upsets

section .bss				;non-initialized but reserved memory
string	resb 30		   		;reserve 30 bytes

section	.text		   		;executive code section
msg		db "hello",10  		;our message + \r
msglen	equ $-msg			;length of msg, $ - current memory address

_start:						;main()
		xor ebx, ebx		;ebx := 0, start of next msg
		mov eax, 5			;eax := 5, counter of msg amount
loop:						;cycle - put msg 5 times in memory
		mov esi, msg   		;adress of msg start
		mov edi, string		;adress of string start
		add edi, ebx   		;start of string + msg's
		mov ecx, msglen		;tell what length of msg to copy
		cld			   		;set direction
		rep movsb	   		;start copy byte-to-byte ecx times
		add ebx, msglen		;calculate start point for next iteration
		dec eax				;decrease counter
		cmp eax, 0			;if it != 0
		jnz loop			;	do again

;; print and exit section ;;
		mov eax, 4			;write
		mov ebx, 1			;	to standard output
		mov ecx, string		;	our string's start
		mov edx, 30			;	30 bytes long
		int 80h				;	syscall (do it)
		
		mov eax, 1			;exit
		mov ebx, 1			;	all ok
		int 80h				;	do it