xref: /freebsd/share/man/man4/amdtemp.4 (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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26.Dd September 5, 2017
27.Dt AMDTEMP 4
28.Os
29.Sh NAME
30.Nm amdtemp
31.Nd device driver for
32.Tn AMD
33processor on-die digital thermal sensor
34.Sh SYNOPSIS
35To compile this driver into the kernel,
36place the following line in your
37kernel configuration file:
38.Bd -ragged -offset indent
39.Cd "device amdtemp"
40.Ed
41.Pp
42Alternatively, to load the driver as a
43module at boot time, place the following line in
44.Xr loader.conf 5 :
45.Bd -literal -offset indent
46amdtemp_load="YES"
47.Ed
48.Sh DESCRIPTION
49The
50.Nm
51driver provides support for the on-die digital thermal sensor present
52in
53.Tn AMD
54Family 0Fh, 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors.
55.Pp
56For Family 0Fh processors, the
57.Nm
58driver reports each core's temperature through sysctl nodes, named
59.Va dev.amdtemp.%d.core{0,1}.sensor{0,1} .
60The driver also creates
61.Va dev.cpu.%d.temperature
62in the corresponding CPU device's sysctl tree, displaying the maximum
63temperature of the two sensors located in each CPU core.
64.Pp
65For Family 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors, the driver reports
66each package's temperature through a sysctl node, named
67.Va dev.amdtemp.%d.core0.sensor0 .
68The driver also creates
69.Va dev.cpu.%d.temperature
70in the corresponding CPU device's sysctl tree, displaying the temperature
71of the shared sensor located in each CPU package.
72.Sh SYSCTL VARIABLES
73The following variable is available as both
74.Xr sysctl 8
75variable and
76.Xr loader 8
77tunable:
78.Bl -tag -width indent
79.It Va dev.amdtemp.%d.sensor_offset
80.El
81Add the given offset to the temperature of the sensor.
82Default is 0.
83.Sh SEE ALSO
84.Xr coretemp 4 ,
85.Xr loader 8 ,
86.Xr sysctl 8
87.Sh HISTORY
88The
89.Nm
90driver first appeared in
91.Fx 7.1 .
92.Sh AUTHORS
93.An Rui Paulo Aq Mt rpaulo@FreeBSD.org
94.An Norikatsu Shigemura Aq Mt nork@FreeBSD.org
95.An Jung-uk Kim Aq Mt jkim@FreeBSD.org
96.Sh CAVEATS
97For Family 10h and later processors,
98.Do
99(the reported temperature) is a non-physical temperature measured on
100an arbitrary scale and it does not represent an actual physical
101temperature like die or case temperature.
102Instead, it specifies the processor temperature relative to the point
103at which the system must supply the maximum cooling for the processor's
104specified maximum case temperature and maximum thermal power dissipation
105.Dc
106according to
107.Rs
108.%T BIOS and Kernel Developer's Guide (BKDG) for AMD Processors
109.%U http://developer.amd.com/resources/developer-guides-manuals/
110.Re
111