Maybe these helps as a start: https://gitlab.com/baylibre/amlogic/atv/u-boot/-/wikis/home https://u-boot.readthedocs.io/en/latest/board/amlogic/sei610.html But it looks like the u-boot.ext Balbes uses is one without de binaries from Amlogic, since he is chaining his bootloader after the boards own u-boot, so memory initialization and soc initialization is already done.
In the meantime the Armbian forums have a separate (very lifely, I might add) 'TV Boxes' part. I can't blame people for thinking that it is part of Armbian. Which it is not. It's not fair to have a TV Boxes section and a special build for them (Oleg's build) and than ranting on all those cheap Chinese TV boxes. Close the whole thing before the good name of Armbian is damaged. In my opinion it is not bad to use open source projects without contributing; I'm a developer myself. But I'm not an expert in all fields. So I contribute to some open source projects (the one I u