Documentation about How to write Display Drivers for JNode

Can someone put up an explanation of how to write display drivers for JNode. Maybe explaining one of the already existing drivers like nvidia. Many more people can contribute to this if there are some instructions or guidelines.

To me someone has to fill

To me someone has to fill in the missing parts of FrameBuffer devices. I'm just trying to add the nVidia Gefore4 4200 Go, but haven't yet the overview to fill in the parts my self.