Anonymous

hellostr:
	.ascii "Hello world!\n"           # 'Hello world!' plus a linefeed character
.equ helloLen, .-hellostr                 # Length of the 'Hello world!' string

.globl _start
_start:
	movq $1, %rax        # The system call for write (sys_write)
	movq $1, %rdi        # File descriptor 1 - standard output
	movq $hellostr, %rsi # Put the offset of hello in ecx
	movq $helloLen, %rdx # helloLen is a constant, so we don't need to say
	                     #  mov edx,[helloLen] to get it's actual value
	syscall              # Call the kernel

	movq $60,  %rax      # The system call for exit (sys_exit)
	xorq %rdi, %rdi      # Exit with return code of 0 (no error)
	syscall