array_test.asm

;; array.asm ;;
;;

global _start

section .bss
array	resb 256			
array2	resb 8			

section .text
;;it is very convinient to write functions before _start

;fill memory (edi=address, ecx = length, al = value)
fill_memory:
		jecxz fm_q		;if ecx = 0 => jump
fm_lp:	mov [edi],al	;put value to array element
		inc edi			;next element
		loop fm_lp		;repeat
fm_q:	ret				;exit function

;;START
_start:					
		mov ecx, 256	;counter
		mov edi, array	;array start
		mov al, '@'		;filling

again:	mov [edi], al	;filling to array element
		inc edi			;next el
		dec ecx			;dec counter
		jnz again		;again if not 0

		mov edi, array2	;prepare to call function
		mov ecx, 8	;
		mov al, 'a'		;
		call fill_memory;call function

;; xor test. fun, but I cant enc inside %rep
		mov ecx, 0				;position in array
%rep 2							;do 2 times - array length
		mov eax, [array2+ecx]	;portion of 4 bytes to eax
		xor eax, [array+ecx]	;xor with 4 bytes from other string
		mov [array2+ecx], eax	;put xored data back
		add ecx, 4				;next portion
%endrep
		mov eax, 10				;breakline code char
		mov [array2+8], eax		;put just after array2 in memory

;; print and exit section ;;
		mov eax, 4		;write
		mov ebx, 1		;	to standard output
		mov ecx, array2	;	our string's start
		mov edx, 9		;	bytes long
		int 80h			;	syscall (do it)
		
		mov eax, 1		;exit
		mov ebx, 1		;	all ok
		int 80h			;	do it