I've made a script that builds an SD card for ArchlinuxARM on the Banana Pi R64.
https://github.com/ericwoud/buildR64arch
It basically installs and configures all necessary packages.
Bpir64 specific packages are in the AUR:
* bpir64-atf-git
* bpir64-mkimage
* linux-bpir64-git
They are pre-build available in my repo, the script takes care of installing it.
My pre-build linux-bpir64-git is in sync with linux-rolling-stable.
A readily downloadable image is available:
https://github.com/ericwoud/buildR64arch/releases/download/v1.1/bpir64-sdmmc.img.xz
Enjoy