It's a zsp400 based processor, I have uploaded the technical manual here:-
http://www.mympxplayer.org/zsp400pdf...-am-df930.html
with the complete instruction set.
There is already an assembler and dissassember which just works with "Rock" .rkp games at the moment, uploaded by Benny here:-
http://www.mympxplayer.org/rockchip-sdk-vt11147.html
Same instruction set. so we have a good start.
and datasheet with example code here:-
http://www.mympxplayer.org/rock26xx-...pdf-df609.html