A hello world program in ARM64 Linux

build.sh

as hello_world.asm -o tmp
ld tmp -o program
./program

hello_world.asm

.section .data
    msg:
        .ascii "Hello world\n"
        len = . - msg

.section .text
    .globl _start

_start:
    mov x0, 1
    ldr x1, =msg
    ldr x2, =len
    mov x8, 64
    svc 0
    mov x8, 93
    mov x0, 0
    svc 0