Highly optimized minimal Debian OS
DietPi is extremely lightweight at its core, our images start at 400MB in size (3x lighter than 'Raspbian Lite'). With features of low process/memory footprint and DietPi-RAMlog installed by default, DietPi allows you to get the maximum performance from your device.
Now it support banana pi BPI-M1
more please see DietPi official:
Source code on github: