Datasheet: http://opensource.rock-chips.com/images/4/4e/Rockchip_RK3288...
Technical Reference Manual: http://rockchip.fr/RK3288%20TRM/
This is on par with what TI offers for its OMAP series, and a great deal better than anything Broadcom has ever released for its RPi SoCs.
I remember around a decade or so ago, Rockchip was one of the main producers of PMP SoCs, mainly the RK26xx and RK27xx series (Actions was the other popular one), and there was a community around firmware-modding those PMPs, including, appropriately enough, porting RockBox to run on them. It's interesting to see them "growing up" in the market.