OpenBSD manual page server

Manual Page Search Parameters

ASMC(4) Device Drivers Manual ASMC(4)

asmcApple System Management Controller (SMC)

asmc0 at isa? port 0x300

The asmc driver provides support for the Apple System Management Controller (SMC), as found in Intel based Apple devices.

The driver possesses a collection of temperature, fan, light, and acceleration sensor values which are made available through the sysctl(8) interface.

If available, the keyboard backlight is enabled by the driver and can be adjusted using the wsconsctl(8) variable keyboard.backlight.

intro(4), isa(4), sensorsd(8), sysctl(8), wsconsctl(8)

The asmc driver first appeared in OpenBSD 5.9.

The asmc driver was written by Joerg Jung <>.

Light sensor values may not be available on older products.

Acceleration sensors are not available and the associated interrupt handling is not implemented.

Besides the sensors, the huge amount of other functions and information available from the SMC is not supported.

December 12, 2015 OpenBSD-6.4