Process startup with serial port as console
I have an Arm CPU board, which boots with a serial port as the default console. It also has a few other serial ports, and I would like to use one of them as the console for an interactive & perpetually running text-mode application. Ideally, this could be started as a system service from /etc/init.d/.... or from something like rc.local. Right now, init spawns a getty on each of the serial ports, so I'm guessing I have to cancel that for the port I would use. The application I want to run just reads and writes its standard input & output, and doesn't, itself, know how to attach to any particular type of console. I just don't know how to start up an application in a serial console, without logging into that console.
An alternative, actually a preference, would be a recipe for cross-building Gnu screen to run on the arm CPU. I could then start it up at boot time, and launch the application inside of that.
Anyone know how to accomplish either of these things?