Assembly HelloWorld, binary size 392 bytes

hello.s

.global _start
.intel_syntax noprefix

_start:
	mov rax, 1
	mov rdi, 1
	lea rsi, [hellomsg]
	mov rdx, 13
	syscall

	mov rax, 60
	mov rdi, 0
	syscall

hellomsg:
	.asciz "Hello World\n"

Makefile

hello: hello.o
	ld hello.o -o hello -s -n

hello.o: hello.s
	as hello.s -o hello.o