MRFIXIT Rockchip Kernel:

This is a fork of Rockchip's BSP kernel, located here: https://github.com/rockchip-linux/kernel

This fork has lots of patches, mainline backports, and custom fixes.

All work has specifically been to support these boards in MrFixIt's releases (found in his other GitHub repositories): RockPi4, Rock64, Rockbox, and Rockpro64