; ASM implementation of 'loop' command (reverse loop)
;
; sum = 0
; for (i = 10; i > 0; i--)
;     sum += i;
;

; include directives
global asm_main
%include "../lib/asm_io.inc"

segment .data
    ; DX directives (read only, static data)

segment .bss
    ; RESX directives (writable data)

segment .text
asm_main:                   ; entry point (called from driver.c)
    ; instructions

    enter 0,0               ; Initialize register EBP
    pusha                   ; Push register contents to the stack
    ;

    mov   eax, 0            ; eax is the sum
    mov   ecx, 10           ; ecx is i

loop_start:
    add   eax, ecx          ; sum += i
    call  print_int         ; print the values for feedback
    call  print_nl          ;
    loop  loop_start        ; if i > 0 then  go to loop_start

    ;
    popa                    ; Restore register data from the stack
    mov   eax, 0            ; flush EAX of data
    leave                   ; restore the stack
    ret                     ; Return from main back into C library wrapper