ASMC(4) 						   BSD Kernel Interfaces Manual 						   ASMC(4)

NAME

     asmc -- device driver for the Apple System Management Console (SMC)

SYNOPSIS

     To compile this driver into the kernel, place the following line in your kernel configuration file:

	   device asmc

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   asmc_load="YES"

DESCRIPTION

     The asmc driver controls the Apple System Management Console (SMC for short) found on Intel Apple systems.

     The SMC is known to be found on the following systems:

	   o   MacBook
	   o   MacBook Pro
	   o   Intel MacMini
	   o   Mac Pro
	   o   MacBook Air
	   o   Intel iMac

     With this driver, you can configure your keyboard backlight brightness, check temperatures of several sensors, check the speed of the inter-
     nal fans and check the status of the Sudden Motion Sensor.

     Variables related to the SMC control and inspection are exported via sysctl(3) under the device tree dev.asmc.

KEYBOARD BACKLIGHT

     On MacBook Pro systems, you can control the keyboard brightness by writing a value to the dev.asmc.%d.light.control sysctl MIB.

     The following sysctl MIBs contains the raw value returned by the left and right light sensors: dev.asmc.%d.light.left or
     dev.asmc.%d.light.right.

TEMPERATURES

     The number of temperature sensors and their description varies among systems.  You can inspect the temperature sensors on your system by
     traversing the dev.asmc.temp sysctl MIB.

     All values are in degrees celsius.

SYSTEM FANS

     The dev.asmc.fan.%d sysctl tree contains the leaf nodes speed, safespeed, minspeed, maxspeed and targetspeed.  Each of these leaf nodes rep-
     resent the current fan speed, the safest minimum fan speed, the minimum speed and the maximum speed respectively.

     All values are in RPM.

SUDDEN MOTION SENSOR

     The Sudden Motion Sensor (SMS for short) is a device that detects laptop movement and notifies the operating system via an interrupt.  The
     sysctl MIBs present under dev.asmc.sms all relate to the SMS.

     The most interesting usage of this device is to park the disk heads when the laptop is moved harshly.  First, you need to install ataidle(8)
     (ports/sysutils/ataidle) and then configure devd(8) the following way:

	   notify 0 {
		   match "system"	   "ACPI";
		   match "subsystem"	   "asmc";
		   action		   "/usr/local/sbin/ataidle -s X Y";
	   };

     Do not forget to change the X and Y values in the command above.

     Also, please note that parking the disk heads too many times can dramatically reduce your hard drive's life span.	Do not rely solely on the
     SMS to protect your hard drive: good care and common sense can increase your hard drive's life.

SEE ALSO

     ataidle(8) (ports/sysutils/ataidle), devd(8), sysctl(8)

HISTORY

     The asmc driver first appeared in FreeBSD 8.0.

AUTHORS

     Rui Paulo <rpaulo@FreeBSD.org> (Google Summer of Code project)

BUGS

     Support for the latest models was never tested and is most likely not fully working.

BSD
								   July 27, 2009							       BSD