mmap_alloc

Example of Linux kernel driver that allows a user-space program to mmap a
buffer of contiguous non-cached physical memory.

Usage from user-level:

1. Find the major number assigned to the driver:

   grep mmap_alloc /proc/devices'

2. Create the special file (assuming major number 254)
   
   mknod /dev/mmap_alloc c 254 0