Just FYI: By simply exchanging U-Boot and the board's .dtb file Armbian is able to run on a Banana Pi M2 which is based on the A31s SoC: http://www.bananapi.com/index.php/forum/general-discussion-for-bpi-m2/995-working-wifi-on-modern-kernels-4-1-tested?start=6 (comprehensive instructions for Arch Linux on the M2 available there)