|MEM(4)||Linux Programmer's Manual||MEM(4)|
NAME¶mem, kmem, port - system memory, kernel memory and system ports
DESCRIPTION¶mem is a character device file that is an image of the main memory of the computer. It may be used, for example, to examine (and even patch) the system. Byte addresses in mem are interpreted as physical memory addresses. References to nonexistent locations cause errors to be returned. Examining and patching is likely to lead to unexpected results when read-only or write-only bits are present. It is typically created by:
mknod -m 660 /dev/mem c 1 1chown root:kmem /dev/memThe file kmem is the same as mem, except that the kernel virtual memory rather than physical memory is accessed. It is typically created by:
mknod -m 640 /dev/kmem c 1 2chown root:kmem /dev/kmemport is similar to mem, but the I/O ports are accessed. It is typically created by:
mknod -m 660 /dev/port c 1 4chown root:mem /dev/port
SEE ALSO¶chown(1), mknod(1), ioperm(2)
COLOPHON¶This page is part of release 3.74 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.