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 non-existent
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 1
chown root:kmem /dev/mem
The 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 2
chown root:kmem /dev/kmem
port
is similar
to mem
, but the I/O
ports are accessed.
It is typically created by:
mknod −m 660 /dev/port c 1 4
chown root:mem /dev/port
SEE ALSO
chown(1), mknod(1), ioperm(2)
Copyright (c) 1993 Michael Haardt (michael@moria.de), Fri Apr 2 11:32:09 MET DST 1993
This is free documentation; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The GNU General Public License's references to "object code"
and "executables" are to be interpreted as the output of any
document formatting or typesetting system, including
intermediate and printed output.
This manual is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public
License along with this manual; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
USA.
Modified Sat Jul 24 16:59:10 1993 by Rik Faith (faith@cs.unc.edu)
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