If something like console=ttyS0 is on the command line, the getty generator kicks in, creating the particular "wants" link: /run/systemd/generator/getty.target.wants/serial-getty@ttyS0.service This ought to work similarly when having console=hvc0 on the line, and that is what it does, at least, the last time I checked with xvc0 (xen) on systemd-210.