NetWinder Button

modulename: nwbutton.ko

configname: CONFIG_NWBUTTON

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>NetWinder Button
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
If you say Y here and create a character device node /dev/nwbutton
with major and minor numbers 10 and 158 ("man mknod"), then every
time the orange button is pressed a number of times, the number of
times the button was pressed will be written to that device.

This is most useful for applications, as yet unwritten, which
perform actions based on how many times the button is pressed in a
row.

Do not hold the button down for too long, as the driver does not
alter the behaviour of the hardware reset circuitry attached to the
button; it will still execute a hard reset if the button is held
down for longer than approximately five seconds.

To compile this driver as a module, choose M here: the
module will be called nwbutton.

Most people will answer Y to this question and "Reboot Using Button"
below to be able to initiate a system shutdown from the button.

source code: