Sorry... I just did the instructions on the first post on this thread. Burned image to SD card, updated through the Update app, etc. I used Armbian_5.67_Aml-s9xxx_Debian_stretch_default_4.19.7_20181218. For Armbian everything worked fine, and I'm also able to boot other things from SD card (LibreElec works) but it won't boot from internal flash when I take the SD card out, and I can't get it into recovery mode. I didn't have to change the dtb file...default worked fine. Thanks!