Kernel-level General Memory-mapping Device Driver

Kernel-level General Memory-mapping Device Driver

If you want to write a driver that lets users access the VME device as memory in user space and also supports DMA and interrupts, you cannot use the general-purpose VME device driver. Instead, you must write a kernel-level device driver of the general memory-mapping model. Likewise, if you need an efficient way to share main memory between a kernel driver and a user program, you must write a device driver of the general memory-mapping model.

The general memory-mapping model is a kernel-level device driver similar to the user-level memory-mapped device driver described above. See Chapter 2, "Writing a Device Driver," for a general description of kernel-level device drivers. See Chapter 7, "Writing Kernel-level General Memory-mapping Device Drivers," for a description of the memory mapping facilities.