I got my first build up and running (still need to fix audio and WIFI) but now I am stuck with dual boot. I installed Ubuntu on a seperate partition and Linux shows up as an option in Clover (actually as two options: "boot from EFI" and "boot from legacy"). But all I get when I try to boot either of them is a black screen and a blinking cursor. Booting into Sierra works fine. At the same time - and I have no idea whether this is connected - after every time I boot Sierra an additional "boot option" (always my SSD) is added to the BIOS. I have read hundreds of threads and it would be great if someone could point me in the right direction. Thanks!