we given command Poweroff its shown below messages
root@beaglebone:~# poweroff
Broadcast message from root@beaglebone (ttyO0) (Wed Apr 23 20:35:20 2014):
The system is going down for system halt NOW!
root@beaglebone:~# Sending SIGTERM to remaining processes...
Sending SIGKILL to remaining processes...
Unmounting file systems.
Unmounted /sys/fs/fuse/connections.
Unmounted /sys/kernel/debug.
Unmounted /sys/kernel/security.
Unmounted /dev/mqueue.
Disabling swaps.
Detaching loop devices.
Detaching DM devices.
[ 937.229621] (NULL device *): gadget not registered.
[ 937.243410] Power down.
[ 937.248426] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000
[ 937.248426]
[ 937.258145] [] (unwind_backtrace+0x1/0x8a) from [] (panic+0x51/0x148)
[ 937.266809] [] (panic+0x51/0x148) from [] (do_exit+0x345/0x618)
[ 937.274932] [] (do_exit+0x345/0x618) from [] (sys_reboot+0xcb/0x13e)
[ 937.283499] [] (sys_reboot+0xcb/0x13e) from [] (ret_fast_syscall+0x1/0x46)
[ 937.292607] drm_kms_helper: panic occurred, switching back to text console