The source code of device simulation such as netcard simulation, lcd simulation etc. is located in device directory. Maybe you need to read device/skyeye_device.c and device/skyeye_device.h in detail to konw about the whole architecture of device simulation. You can refer to some existing implementation.
Now the device simulation architecture of SkyEye is a kind of module-register mechinism. We try to make the device simulation machine-independent and arch-independent. But it seems not implemented completely.