RTD1186

Looks to be a 750mhz MIPS developed by Realtek

Pricing from various sources varies between $1.90 and $3.80 for 10k quantities which is still absolutely stunning and justifies a rather urgent push to get hold of the datasheet. More information on pricing shows that the actual price direct from Realtek is $11.

Source code, software and firmware links

GPU

Unpacking the firmware from one of the source code links shows that the GPU is a PowerVR SGX 531.