other tools/implementations

- https://github.com/collabora/rockchiprs
- https://github.com/xboot/xrock
- https://github.com/rockchip-linux/rkdeveloptool/blob/master/RKDevice.cpp
- https://github.com/linux-rockchip/rkflashtool/blob/master/rkflashtool.c
- https://opensource.rock-chips.com/wiki_Upgradetool
- https://opensource.rock-chips.com/wiki_Rockusb