[korse]

This may help you.

https://dji.retroroms.info

Check out the faq/start. I haven't looked into minis, but the larger mavics are well supported.

If you want to really have some fun with your current drone, check out a program called Litchi. It costs lunch to get a copy but it gives you a full ground station with mission planning capabilities, a Google Cardboard compatible FPV function (a bit laggy for precision flying but if you pick you lines through obstacles you will be fine), limited head tracking that moves the camera gimbal as you look around and a heads up display / audio feedback.

All in all, modified dji + litchi + google cardboard headset + burner android phone is a surprisingly capable package that can be repaired, tweaked and has a very low price point if you can navigate the used goods market.