Commit | Line | Data |
---|---|---|
1b5de69d WJ |
1 | .\" Copyright (c) 1990, 1991 Regents of the University of California. |
2 | .\" All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 3. All advertising materials mentioning features or use of this software | |
13 | .\" must display the following acknowledgement: | |
14 | .\" This product includes software developed by the University of | |
15 | .\" California, Berkeley and its contributors. | |
16 | .\" 4. Neither the name of the University nor the names of its contributors | |
17 | .\" may be used to endorse or promote products derived from this software | |
18 | .\" without specific prior written permission. | |
19 | .\" | |
20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | .\" SUCH DAMAGE. | |
31 | .\" | |
32 | .\" @(#)mem.4 5.2 (Berkeley) 3/27/91 | |
33 | .\" | |
34 | .Dd March 27, 1991 | |
35 | .Dt MEM 4 hp300 | |
36 | .Os | |
37 | .Sh NAME | |
38 | .Nm mem , | |
39 | .Nm kmem | |
40 | .Nd main memory | |
41 | .Sh DESCRIPTION | |
42 | The file | |
43 | .Nm /dev/mem | |
44 | is an interface to the physical memory of the | |
45 | computer. | |
46 | Byte offsets in this file are interpreted as physical memory addresses. | |
47 | Reading and writing this file is equivalent to reading and writing | |
48 | memory itself. | |
49 | An error will be returned if an attempt is made to reference | |
50 | an offset outside of | |
51 | .Nm /dev/mem . | |
52 | .Pp | |
53 | Kernel virtual memory is accessed via the file | |
54 | .Nm /dev/kmem | |
55 | in the same manner as | |
56 | .Nm /dev/mem . | |
57 | Only kernel virtual addresses that are currently mapped to memory are allowed. | |
58 | .Sh HP300 | |
59 | On the | |
60 | .Tn HP300 , | |
61 | the last byte of physical memory is always | |
62 | .Li 0xFFFFFFFF . | |
63 | Therefore, on an | |
64 | .Tn HP300 | |
65 | with | |
66 | 8Mb of memory, physical memory would start | |
67 | at | |
68 | .Li 0xFF800000 . | |
69 | On the | |
70 | .Tn HP300 , | |
71 | kernel virtual memory runs from | |
72 | .Li 0 | |
73 | to about | |
74 | .Li 0x2400000 . | |
75 | .Sh FILES | |
76 | .Bl -tag -width /dev/kmem -compact | |
77 | .It Pa /dev/mem | |
78 | .It Pa /dev/kmem | |
79 | .El | |
80 | .Sh HISTORY | |
81 | The files | |
82 | .Nm mem | |
83 | and | |
84 | .Nm kmem | |
85 | appeared in | |
86 | .At v6 . |