dev/nasm/lnxhello/lnxhello.asm

50 lines
635 B
NASM

;
; Assembly "Hello, World!" for Linux
;
; Properly defined in <sys/syscall.h>
%define SYS_exit 1
%define SYS_write 4
section .text
global _start
_start:
; gdb doesn't like to stop at the entry point address, so
; we put a nop here for pure convenience
nop
write_hello:
mov edx, hello_len
mov ecx, hello
.loop:
mov eax, SYS_write
mov ebx, 1 ; stdout
int 80h
cmp eax, -4096
ja error
add ecx, eax
sub edx, eax
jnz .loop
ok:
mov eax, SYS_exit
xor ebx, ebx
int 80h
hlt
error:
mov eax, SYS_exit
mov ebx, 1 ; Error
int 80h
hlt
section .rodata
hello: db "Hello, World!", 10
hello_len equ $-hello