asm_write_syscall.s

.data
msg:
        .ascii  "hello, world\n"
len = . - msg

.text

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

        mov x0, #0
        mov x8, #93
 
; In Makefile

; default: main
;         ./main
;
; main: main.s
;         as -o main.o main.s
;         ld -o main main.o
;
; clean:
;         rm main.o
;         rm main
        svc #0