;;
;; helloworld.asm
;;
;; Class "hello world" in x86_64 assembly using NASM and Linux system
;; calls for I/O.
;;
;; by T.Sergeant
;;
;; nasm -f elf64 helloworld.asm
;; ld helloworld.o
;; ./a.out
;;

		global _start
		section .data

message:	db	"Hello, World!",10
message_len:	equ	$-message


		section .text

_start:
		; write(stdout,message,length)
		mov     rax, 1			; system call 1 is write
		mov     rdi, 1			; file handle 1 is stdout
		mov     rsi, message		; address of string to output
		mov     rdx, message_len	; number of bytes in string
		syscall

		; exit(0)
		mov     rax, 60                 ; system call 60 is exit
		xor     rdi, rdi                ; exit code 0
		syscall