The board is powered via USB and your are warned that it requires 2 amps. In theory this means that powering from a plain old USB port will not do. (nonetheless, see below) For my initial tests I used a 2 amp "Samsung" branded wall module intended for my cell phone that was laying around and it seemed to work just fine.
As it turns out, a plain old USB cable from my computer (restricted to 500 mA) seems to work just fine for everything I have done thus far. It even works to boot unix, though I am certain that problems will crop up if I get the board busy doing things with all the cores running.
I downloaded the 64 bit image s5p6818-friendly-core-xenial-4.4-arm64-20180615.img (provided as a zip file, but just unzip it to get the plain image). I used "dd" to copy it onto a 8G micro SD card and it booted right up. While I was at it, I grabbed a copy of the linux sources in the manner instructed in the Friendly ARM Wiki.
The system comes up running user "pi". You need to su to root with password "fa" to do a clean shutdown. Use halt or "shutdown now".
pi@NanoPi-Fire3:~$ uname -a Linux NanoPi-Fire3 4.4.49-s5p6818 #1 SMP PREEMPT Wed May 9 14:01:02 CST 2018 aarch64 aarch64 aarch64 GNU/Linux pi@NanoPi-Fire3:~$ df Filesystem 1K-blocks Used Available Use% Mounted on udev 383552 0 383552 0% /dev tmpfs 96812 3244 93568 4% /run /dev/mmcblk0p2 7517744 4585644 2915716 62% / tmpfs 488152 0 488152 0% /dev/shm tmpfs 5120 4 5116 1% /run/lock tmpfs 488152 0 488152 0% /sys/fs/cgroup tmpfs 97632 0 97632 0% /run/user/1000No heat sink yet. No telling what the clock rate is. Chip gets noticeably but not alarmingly hot, but it is just idling.
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