This is how I got Armory (etotheipi/BitcoinArmory; http://bitcoinarmory.com/) cross-compiled for the Raspberry Pi.
This is a great way to keep an air-gapped offline wallet for only $30 dollars for the RPi (that you can also use for other things; experiment, it's awesome) and $7 for a Class 10 4GB SD card, really easy to keep in a safe and secret place.