use ./fel-run-linux.sh to run installer, note that you need usb bus rights for ADB (android debug bridge).
either use sudo ( bad idea ) or follow some guide to setup udev rules
eg: https://askubuntu.com/questions/213874/how-to-configure-adb-access-for-android-devices
Armbian installation is not yet supported, but space reservation can be done then use h3resc to complete task.
fel-installer boot uses mainline u-boot, H3Droid Armbian kernel, busybox, micropython and debian jessie armhf.