Setting Exit Status in NASM for Windows

Question

I'm currently trying to learn some basic x86 assembly and running into some difficulties running it on Windows. All I'm trying to do is set the exit status. I'm aware of how to do this if I was on Linux:

global _start
_start:
    mov eax,1
    mov ebx, 52
    int 0x80

Obviously this will give exit status 52. How do I do this on Windows? I looked all over but couldn't find a clear answer.

You can't use `int 0x80` on Windows. Instead, you call the library function ExitProcess and pass the exit status as a parameter. — David Wohlferd, Dec 28 '21 at 19:02
Every nasm program for Windows is going to use ExitProcess, so [google](https://www.davidgrantham.com/nasm-console32/) should be able to turn something up for you. — David Wohlferd, Dec 28 '21 at 20:10

score 1 · Accepted Answer · answered Dec 29 '21 at 22:45

How do I do this on Windows? I looked all over but couldn't find a clear answer.

That is the issue here: There is no clear answer. Windoze is a mess. Use Linux and be happy. :−)

As it’s already been mentioned, there is no universal method to interface with the OS. On WinD0S, for instance, it would’ve been int 21h:

segment code

start:
    mov ah, 0x4C   ; function `exit – terminate with return code`
    mov al, 52     ; return code
    int 0x21       ; DOS kernel interrupt

What you probably wanna do is, as David Wohlferd already pointed out, use ExitProcess:

global start

extern _ExitProcess@4

section .text

start:
    push 52
    call _ExitProcess@4

On a GNU/Linux Debian(-like) system with a wine(1) installation the steps look like:

nasm -f win32 -o exitdemo.obj exitdemo.asm
i686-w64-mingw32-ld exitdemo.obj -lkernel32 -o exitdemo.exe
wine ./exitdemo.exe; echo $?

thanks, but "be happy" is not a concept while programming assembly — Krusty the Clown, Jan 03 '22 at 18:30

Setting Exit Status in NASM for Windows

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