This, along with the fact that there is no power LED on the board, leads people to believe boards they purchased are dead. Until some software starts up, and writes to the GPIO to turn on the status LED, the board will appear dead.
My board runs amazingly cool (with just one core active). I do have a heat sink mounted on the CPU.
The board I experiment with is difficult to get to the U-boot prompt. It tells you to type space, and apparently that is the only key that gets you in (unlike "normal" U-boot builds).
I have edited the file /boot/boot.scr to make this board do what I want (boot via DHCP). This means that there is no way to interrupt U-boot using the space and then tell it to boot linux. To do that, you will have to pull the card, put it into a card reader, and change boot.scr. It also means that my change to "bootdelay" in that script is useless. The script doesn't run until bootcmd performs the "boot_mmc" command.
The boot announces itself as:
U-Boot 2020.04-armbian (Jun 03 2020 - 07:47:47 +0200) Allwinner TechnologySo presumably this would run Armbian "Buster" if I did ask it to boot linux for me. I have another card set up to just boot Armbian, and by far just using it would be the easiest way (at this time) to get linux running on this board.
Tom's electronics pages / tom@mmto.org