AMDTEMP(4) BSD Kernel Interfaces Manual AMDTEMP(4)
NAME
amdtemp -- device driver for AMD processor on-die digital thermal sensor
SYNOPSIS
To compile this driver into the kernel, place the following line in your kernel configuration file:
device amdtemp
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
amdtemp_load="YES"
DESCRIPTION
The amdtemp driver provides support for the on-die digital thermal sensor present in AMD Family 0Fh, 10h, 11h, 12h, 14h, and 15h processors.
For Family 0Fh processors, the amdtemp driver reports each core's temperature through sysctl nodes, named
dev.amdtemp.%d.core{0,1}.sensor{0,1}. The driver also creates dev.cpu.%d.temperature in the corresponding CPU device's sysctl tree, display-
ing the maximum temperature of the two sensors located in each CPU core.
For Family 10h, 11h, 12h, 14h, and 15h processors, the driver reports each package's temperature through a sysctl node, named
dev.amdtemp.%d.core0.sensor0. The driver also creates dev.cpu.%d.temperature in the corresponding CPU device's sysctl tree, displaying the
temperature of the shared sensor located in each CPU package.
SYSCTL VARIABLES
The following variable is available as both sysctl(8) variable and loader(8) tunable:
dev.amdtemp.%d.sensor_offset
Add the given offset to the temperature of the sensor. Default is 0.
SEE ALSO
loader(8), sysctl(8)
HISTORY
The amdtemp driver first appeared in FreeBSD 7.1.
AUTHORS
Rui Paulo <rpaulo@FreeBSD.org>
Norikatsu Shigemura <nork@FreeBSD.org>
Jung-uk Kim <jkim@FreeBSD.org>
CAVEATS
For Family 10h and later processors, ``(the reported temperature) is a non-physical temperature measured on an arbitrary scale and it does
not represent an actual physical temperature like die or case temperature. Instead, it specifies the processor temperature relative to the
point at which the system must supply the maximum cooling for the processor's specified maximum case temperature and maximum thermal power
dissipation'' according to BIOS and Kernel Developer's Guide (BKDG) for AMD Processors,
http://developer.amd.com/documentation/guides/Pages/default.aspx.
BSD
February 23, 2012 BSD