ExASM

ex.asm

section .text
	global _start

_start:  ; program entry point
	mov eax, 0x04	; system_call sys_write
	mov ebx, 0x01	; stdout
	mov ecx, msg	; assign msg to ecx
	mov edx, msglen ; assign edx to msglen
	int 0x80		; call kernel
	mov eax, 0x01	; sys_call sys_exit
	mov ebx, 0x05	;
	int 0x80		; call kernel

section .data
	msg	db		"I'm going to do this!", 0xa
	msglen	equ		$ - msg

Makefile

all:
	nasm -f elf64 foo.asm -o foo.o
	ld -o foo foo.o