84 lines
2.8 KiB
Groff
84 lines
2.8 KiB
Groff
.\" Copyright (c) 1991 The Regents of the University of California.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" from: @(#)mem.4 5.3 (Berkeley) 5/2/91
|
|
.\" $Id: mem.4,v 1.2 1993/08/01 07:37:00 mycroft Exp $
|
|
.\"
|
|
.Dd May 2, 1991
|
|
.Dt MEM 4 i386
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mem ,
|
|
.Nm kmem
|
|
.Nd memory files
|
|
.Sh DESCRIPTION
|
|
The special file
|
|
.Nm /dev/mem
|
|
is an interface to the physical memory of the computer.
|
|
Byte offsets in this file are interpreted as physical memory addresses.
|
|
Reading and writing this file is equivalent to reading and writing
|
|
memory itself.
|
|
Only offsets within the bounds of
|
|
.Nm /dev/mem
|
|
are allowed.
|
|
.Pp
|
|
Kernel virtual memory is accessed through the interface
|
|
.Nm /dev/kmem
|
|
in the same manner as
|
|
.Nm /dev/mem .
|
|
Only kernel virtual addresses that are currently mapped to memory are allowed.
|
|
.Pp
|
|
On
|
|
.Tn ISA
|
|
the
|
|
.Tn I/O
|
|
memory space begins at physical address 0x000a0000
|
|
and runs to 0x00100000.
|
|
The
|
|
per-process data
|
|
size
|
|
for the current process
|
|
is
|
|
.Dv UPAGES
|
|
long, and ends at virtual
|
|
address 0xfe000000.
|
|
.Sh FILES
|
|
.Bl -tag -width Pa -compact
|
|
.It Pa /dev/mem
|
|
.It Pa /dev/kmem
|
|
.El
|
|
.Sh HISTORY
|
|
The
|
|
.Nm mem ,
|
|
.Nm kmem
|
|
files appeared in
|
|
.At v6 .
|