DESCRIPTION
 The 
gpiolock driver allows connecting of multi-position keylocks over GPIO pins. The keylock driver registers with an in-kernel keylock supporting system and provides 
kauth(9) support through an experimental security model. The keylock state can be queried using the hw.keylock sysctl variables. Only locks with 2-4 positions are currently supported. The pin number is specified in the kernel configuration with the 
offset locator. The 
mask locator denotes the pins used for the lock (minimum 2, maximum 4 pins are used). The 
offset and 
mask can also be specified when 
gpiolock is attached at runtime using the 
GPIOATTACH ioctl(2) on the 
gpio(4) device.