gcc -o arraytest.exe arraytest.c arrayinc.obj

// File: arraytest.c
//
// C program to test arrayinc.asm
//

#include <stdio.h>

void arrayinc(int A[], int n) ;

main() {

int A[7] = {2, 7, 19, 45, 3, 42, 9} ;
int i ;

   printf ("sizeof(int) = %d\n", sizeof(int)) ;

   printf("\nOriginal array:\n") ;
   for (i = 0 ; i < 7 ; i++) {
      printf("A[%d] = %d  ", i, A[i]) ;
   }
   printf("\n") ;

   arrayinc(A,7) ;

   printf("\nModified array:\n") ;
   for (i = 0 ; i < 7 ; i++) {
      printf("A[%d] = %d  ", i, A[i]) ;
   }
   printf("\n") ;
   
}


-----------------------------------

; File: arrayinc.asm
;
; A subroutine to be called from C programs.
; Parameters: int A[], int n
; Result: A[0], ... A[n-1] are each incremented by 1


        SECTION .text
        global _arrayinc

_arrayinc:
        push    ebp                     ; set up stack frame
        mov     ebp, esp

        ; registers ebx, esi and edi must be saved, if used
        push    ebx
        push    edi

        mov     edi, [ebp+8]            ; get address of A
        mov     ecx, [ebp+12]           ; get num of elts
        mov     ebx, 0                  ; initialize count

for_loop:
        mov     eax, [edi+4*ebx]        ; get array element
        inc     eax                     ; add 1
        mov     [edi+4*ebx], eax        ; put it back
        inc     ebx                     ; update counter
        loop    for_loop

        pop     edi                     ; restore registers
        pop     ebx
       
        mov     esp, ebp                ; take down stack frame
        pop     ebp

        ret
----------------------------------------

nasm -f obj arrayinc.asm