section .data
hello_world db "Hello World from RJM Programming and wonderful advice of http://thexploit.com/secdev/mac-os-x-64-bit-assembly-system-calls/ ... thanks!", 0x0a
 
section .text
global start
 
start:
mov rax, 0x2000004      ; System call write = 4
mov rdi, 1              ; Write to standard out = 1
mov rsi, hello_world    ; The address of hello_world string
mov rdx, 136            ; The size to write
syscall                 ; Invoke the kernel
mov rax, 0x2000001      ; System call number for exit = 1
mov rdi, 0              ; Exit success = 0
syscall                 ; Invoke the kernel