xref: /netbsd-src/share/man/man4/spdmem.4 (revision 68e94d49dda1e61280355acca6e0518deee7dcad)
1.\"	$NetBSD: spdmem.4,v 1.8 2016/07/27 08:38:25 wiz Exp $
2.\"
3.\"Copyright (c) 2007 Nicolas Joly
4.\"Copyright (c) 2007 Paul Goyette
5.\"All rights reserved.
6.\"
7.\"Redistribution and use in source and binary forms, with or without
8.\"modification, are permitted provided that the following conditions
9.\"are met:
10.\"1. Redistributions of source code must retain the above copyright
11.\"   notice, this list of conditions and the following disclaimer.
12.\"2. Redistributions in binary form must reproduce the above copyright
13.\"   notice, this list of conditions and the following disclaimer in the
14.\"   documentation and/or other materials provided with the distribution.
15.\"3. The name of the author may not be used to endorse or promote products
16.\"   derived from this software without specific prior written permission.
17.\"
18.\"THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
19.\"``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20.\"TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21.\"PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22.\"BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23.\"CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24.\"SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25.\"INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26.\"CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27.\"ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28.\"POSSIBILITY OF SUCH DAMAGE.
29.\"
30.Dd July 27, 2016
31.Dt SPDMEM 4
32.Os
33.Sh NAME
34.Nm spdmem
35.Nd Generic Memory Module Serial Presence Detect
36.Sh SYNOPSIS
37.Cd "spdmem* at iic? addr 0x50"
38.Cd "spdmem* at iic? addr 0x51"
39.Cd "spdmem* at iic? addr 0x52"
40.Cd "spdmem* at iic? addr 0x53"
41.Cd "spdmem* at iic? addr 0x54"
42.Cd "spdmem* at iic? addr 0x55"
43.Cd "spdmem* at iic? addr 0x56"
44.Cd "spdmem* at iic? addr 0x57"
45.Sh DESCRIPTION
46The
47.Nm
48driver provides support for generic memory module Serial Presence Detect.
49During kernel boot it displays module type, and where possible, the size and
50rated speed of the memory module.
51Additional information such as bank configuration and width is
52printed if the kernel is booted in verbose mode.
53.Pp
54The Serial Presence Detect data for each memory module is also made accessible
55to user mode via
56.Xr sysctl 8 .
57An entry for each
58.Nm
59device is created under the
60.Dv hw
61top-level MIB.
62.Pp
63Some SPD ROMs also have a temperature sensor.
64It's supported by
65.Xr sdtemp 4 .
66.Sh SEE ALSO
67.Xr iic 4 ,
68.Xr intro 4 ,
69.Xr sdtemp 4
70.Sh HISTORY
71The
72.Nm
73driver first appeared in
74.Nx 5.0 .
75.Sh AUTHORS
76.An -nosplit
77The
78.Nm
79driver was written by
80.An Nicolas Joly Aq Mt njoly@pasteur.fr
81with additional work by
82.An Paul Goyette Aq Mt paul@whooppee.com .
83