I have an image for rockchip boxes in my drive, that I think can help rockchip tv users a bit more.
https://drive.google.com/drive/folders/13o1S4G5Z3QSoWHrFcC_WPkcFDihUului?usp=sharing
It has uboot for nanopc t4 but this can be changed with others included in RK_uboot. Which u-boot works with your box is your task. Making the trials is easy because the flash is made in seconds. So in order to get an install on sd card:
1.- Burn manjaro image with balena etcher.
2.- Burn boot image (e.g. u-boot-rk3399-renegade-elite.img) in the same card with balena etcher. Try booting and if it fails you can do this flash again with another boot image.
3.- Add a dtb file to extlinux.conf that can work with your box.
The roc_pc image remains because uboot is different.
With SD card in the unpowered box press reset and power on. The reset button in the sound jack must be pressed with a toothpick while powering. Wait 10 seconds and release the reset. I don’t have to do that. anymore, because I think after first botting is enabled the sd-booting…
Good luck!
Working on superpow MXQ max leelbox q4