Which service creates the /dev/ttyOX symlinks for UARTs?

Hi!

Which systemd unit initializes the ttyOX symlinks to UARTs (/dev/ttyO1,...) during boot? In the 2017-01-15 seeed-iot image.

I wish to start my service which expects those links to be there, so I'd need to pass to it the correct "After" dependency. Until now I thought "capemgr" service created the links, but apparently it doesn't. Maybe udev then?

Switched to /dev/ttySX after discovering that the /dev/ttyOX devices are for backwards compatibility and not needed.

Somehow systemd manages those as well, so I had to add this line to my unit to wait for /dev/ttyS2 to be “ready” (which, in this case, means adding read-write permissions for group “dialout”)
After=dev-ttyS2.device