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

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

The following figure shows the video miniport driver within the NT-based operating system graphics subsystem.
Diagram illustrating the NT-based operating system graphics architecture

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.
(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。)

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.


A display driver cannot handle device interrupts, and only the miniport driver can set up device memory and map it into a display driver
（显示驱动不能出来设备中断，只有小端口驱动能够处理）