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, displaying 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.