xref: /freebsd/share/man/man4/amdtemp.4 (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
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26.\" $FreeBSD$
27.\"
28.Dd September 5, 2017
29.Dt AMDTEMP 4
30.Os
31.Sh NAME
32.Nm amdtemp
33.Nd device driver for
34.Tn AMD
35processor on-die digital thermal sensor
36.Sh SYNOPSIS
37To compile this driver into the kernel,
38place the following line in your
39kernel configuration file:
40.Bd -ragged -offset indent
41.Cd "device amdtemp"
42.Ed
43.Pp
44Alternatively, to load the driver as a
45module at boot time, place the following line in
46.Xr loader.conf 5 :
47.Bd -literal -offset indent
48amdtemp_load="YES"
49.Ed
50.Sh DESCRIPTION
51The
52.Nm
53driver provides support for the on-die digital thermal sensor present
54in
55.Tn AMD
56Family 0Fh, 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors.
57.Pp
58For Family 0Fh processors, the
59.Nm
60driver reports each core's temperature through sysctl nodes, named
61.Va dev.amdtemp.%d.core{0,1}.sensor{0,1} .
62The driver also creates
63.Va dev.cpu.%d.temperature
64in the corresponding CPU device's sysctl tree, displaying the maximum
65temperature of the two sensors located in each CPU core.
66.Pp
67For Family 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors, the driver reports
68each package's temperature through a sysctl node, named
69.Va dev.amdtemp.%d.core0.sensor0 .
70The driver also creates
71.Va dev.cpu.%d.temperature
72in the corresponding CPU device's sysctl tree, displaying the temperature
73of the shared sensor located in each CPU package.
74.Sh SYSCTL VARIABLES
75The following variable is available as both
76.Xr sysctl 8
77variable and
78.Xr loader 8
79tunable:
80.Bl -tag -width indent
81.It Va dev.amdtemp.%d.sensor_offset
82.El
83Add the given offset to the temperature of the sensor.
84Default is 0.
85.Sh SEE ALSO
86.Xr coretemp 4 ,
87.Xr loader 8 ,
88.Xr sysctl 8
89.Sh HISTORY
90The
91.Nm
92driver first appeared in
93.Fx 7.1 .
94.Sh AUTHORS
95.An Rui Paulo Aq Mt rpaulo@FreeBSD.org
96.An Norikatsu Shigemura Aq Mt nork@FreeBSD.org
97.An Jung-uk Kim Aq Mt jkim@FreeBSD.org
98.Sh CAVEATS
99For Family 10h and later processors,
100.Do
101(the reported temperature) is a non-physical temperature measured on
102an arbitrary scale and it does not represent an actual physical
103temperature like die or case temperature.
104Instead, it specifies the processor temperature relative to the point
105at which the system must supply the maximum cooling for the processor's
106specified maximum case temperature and maximum thermal power dissipation
107.Dc
108according to
109.Rs
110.%T BIOS and Kernel Developer's Guide (BKDG) for AMD Processors
111.%U http://developer.amd.com/resources/developer-guides-manuals/
112.Re
113