1) Is this build hardcoded to speak to Videostrong hardware, or does it contain the full DTB tree for the tons of rk3399 variants, such that if I threw it on my pine rockpro64, it would figure itself out?
2) What kernel version is it? ( if it's not exactly 4.4.138 I will be unable to use it, because my designware/synposis "i2s"/bridge driver goes bad past 4.4.138 which is what my rockpro64 uses for HDMI-carried audio I think?; anyway >4.4.138 floods dmesg with 'fail to clear' errors and audio goes -1,000x speed, sounds like a demon when you play a file if using >4.4.138). How would I even begin getting help with that?
This build was never intended to drive anything but vs-rk3399. Even if SoCs are same, vendors pick and choose what features to implement and how to implement them. So you might get lucky if this build works on your board, but no guarantee.
Also this build uses kernel v4.4.154.