Hello World in GNU Assembly (OpenBSD 7.9, x86-64)

helloworld.s

# cc -nostdlib -no-pie -static helloworld.s -o helloworld && strip helloworld

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

        .text
        .globl  _start

_start:
        mov     $4, %eax
        mov     $1, %edi
        mov     $msg, %rsi
        mov     $len, %rdx
addr_write:
        syscall

        mov     $1, %eax
        xor     %edi, %edi
addr_exit:
        syscall

        .section        .openbsd.syscalls, "a"
        .long   addr_write, 4
        .long   addr_exit, 1

        .section        .note.openbsd.ident, "a"
        .long   8, 4, 1
        .ascii  "OpenBSD\0"
        .long   0

I'm revisiting amd64 Assembly programming on OpenBSD and this is a great example. Thank you!