Intel has been the leading graphic card manufacturer to OpenSource the graphic drivers. Now the fully documentaion is released:
The PRM describes the architectural behavior and programming environment of the chipset and graphics devices. The GMCH’s Graphics Controller (GC) contains an extensive set of registers and instructions for configuration, 2D, 3D, and Video systems. The PRM describes the register, instruction, and memory interfaces and the device behaviors as controlled and observed through those interfaces. The PRM also describes the registers and instructions and provides detailed bit/field descriptions. This information is critical to the development and maintenance of Intel graphics drivers for this hardware.
Take a look at: http://intellinuxgraphics.org/index.html
