Today I received my BPI-M7 (ArmSoM-Sige7).
So I can now introduce my buildscript for the BPI-M7. Still in Alfa phase, but the boards boots. Should even be able to boot from nvme 
It boots mainline U-Boot and mainline linux (collabora version).
For now, only input/output on UART2 (on 40pin header). Be carefull, 3.3V only!
So only booting until command prompt tested, the rest all still have to test.
1 of the two ethernet ports should be setup to have an ip number (still have to figure out which one). Should be ssh access to it.