9.4. Using I/O Memory9.4. Using I/O Memory Despite the popularity of I/O ports in the x86 world, the main mechanism used to communicate with devices is through memory-mapped registers and device memory. Both are called I/O memory because the difference between registers and memory is transparent to software. I/O memory is simply a region of RAM-like locations that the device makes available to the processor over the b
http://www.makelinux.net/kernel_map/
http://www.makelinux.net/books/ulk3/
