CSC231 Crash Course Solution 7

--D. Thiebaut 15:10, 4 March 2011 (EST)

---

;;; prog7.asm
;;; D. Thiebaut
;;; solution for Exercise #7
;;; 
;;; Assemble, link and run as follows:
;;;   nasm -f elf asm_io.asm        (do this only once)
;;;   nasm -f elf prog7.asm
;;;   gcc -o prog7 driver.c prog7.o asm_io.o
;;;   ./prog7
;;; 
%include "asm_io.inc"
        
%assign SYS_EXIT        1

        ;; -------------------------
        ;; data segment
        ;; -------------------------
        section .data
A       dd      1, 0, 2, 0, 5
B       dd      1, 0, 0, 3, 1, 2, 0, 0, 9, 7

        ;; -------------------------
        ;; code area
        ;; -------------------------
        section .text
        global  asm_main
;;; ----------------------------------------------------------------
;;; printNotZero: receives the address of an array in esi, and the
;;;               number of items in ecx, and prints only the
;;;               items that are not 0
;;; ----------------------------------------------------------------
printNotZero:

for:    mov     eax, [esi]
        cmp     eax, 0
        je      done
        call    print_int
        call    print_nl
done:   add     esi, 4
        loop    for
        ret
        
        
;;; ----------------------------------------------------------------
;;;                M A I N   P R O G R A M
;;; ----------------------------------------------------------------
asm_main:
        mov     esi, A
        mov     ecx, 5
        call    printNotZero

        mov     ecx, 3
for2:   call    print_nl              ; print 3 blank lines
        loop    for2
        
        mov     esi, B
        mov     ecx, 10
        call    printNotZero

        ;; return to C program

        ret