NSA320: how to manually flash UBoot 2016.09?

[summers]

Lets see, my /etc/fstab has:
$this->bbcode_second_pass_code('', '/dev/sda1 / ext4 defaults,noatime 0 1
/dev/sda3 none swap sw 0 0
/dev/sda4 /home btrfs noatime,autodefrag,compress=zlib,space_cache 0 2
tmpfs /tmp tmpfs nodev,nosuid 0 0
')