Dobrica Pavlinušić's random unstructured stuff
M8S PRO: Revision 4
Board sticker: M8S PRO R4 S912 3G 32G DDR4 DQ

probably: https://www.geekbuying.com/item/MECOOL-M8S-PRO-S912-KODI-17-0-4K-HDR10-3GB-DDR4-32GB-eMMC-TV-Box-380737.html

^ recovery sd

https://www.cnx-software.com/2016/11/19/how-to-create-a-bootable-recovery-sd-card-for-amlogic-tv-boxes/

^ amlogic info

http://www.linux-meson.com/doku.php

^ armbian

https://yadi.sk/d/5_32km_EsCV2A/ARMBIAN

^ u-boot

https://github.com/endlessm/u-boot-meson