We have an A5 linux box around here that we got it running on, but it’s not something you’ll be able to get running easily on your own right now.
It requires using a custom shell script instead of the service wrapper to start Ignition (not that hard), and an ignition-arm*.so file compiled specifically for that platform (impossible for you to do youself).
KSB has plans to sell an ARM-based data collection box in the near future, maybe Kyle can step in and give you more info.
Edit: I’m talking about running a gateway. Oops. Running a client should be a bit easier, and won’t require the shell script or native binary. We have an A7 tablet here that runs the client like a champ.