;run on Linux with: nasm -felf64 decrement.asm && ld decrement.o && ./a.out

global _start

section .text

_start:
  mov rax, 0xDEADBEEF
  call decrement
  call exit

decrement:
  dec rax
  cmp rax, 0
  jg decrement
  ret

exit:
  mov rax, 60
  syscall
``