Unix news is nothing but opensourse - this site features general information about Linux/Unix/Perl programming language.
Sunday, February 03, 2008
IO Memory Access
Unlike on most typical embedded systems, accessing I/O memory on Linux cannot be done directly. This is due to the wide range of different memory types and maps present on the wide range of processors on which Linux runs. To access I/O memory in a portable manner, you must call ioremap() to gain access to a memory region and iounmap() to release access.read more.