Video Miniport Driver Within the Graphics Architecture (Windows 2000 Model)

http://msdn.microsoft.com/en-us/library/windows/hardware/ff570519%28v=vs.85%29.aspx

1. Video Miniport Driver Within the Graphics Architecture (Windows 2000 Model)
   
2. 
   
3. The following figure shows the video miniport driver within the NT-based operating system graphics subsystem.
   
4. Diagram illustrating the NT-based operating system graphics architecture
   
5. 
   
6. Each video miniport driver provides hardware-level support for a display driver. The display driver calls the graphics engine EngDeviceIoControl function to request support from the underlying video miniport driver. EngDeviceIoControl, in turn, calls an I/O system service to send the request through the video port driver to the miniport driver.
7. (小端口驱动提供硬件级别的支持给显示驱动。显示驱动调用EngDeviceIoControl函数从底层的视频小端口驱动获得支持。EngDeviceIoControl调用I/O系统服务通过视频端口驱动发送请求给小端口驱动。)
   
8. 
   
9. In most circumstances, the display driver carries out time-critical operations that are visible to the user, while the underlying miniport driver provides support for infrequently requested operations or for truly time-critical operations that cannot be preempted by an interrupt or a context switch to another process.
10. 
    
11. 
    
12. A display driver cannot handle device interrupts, and only the miniport driver can set up device memory and map it into a display driver
13. （显示驱动不能出来设备中断，只有小端口驱动能够处理）