title: Error while trying to enter sleep mode in Beagle Bone Black
body: <p>While trying to enter sleep mode on beaglebone black am getting an error
  When i issue the command <code>echo -n "mem" &gt; /sys/power/state</code> am getting 
  <code>-sh: echo: write error: No such device</code>
  The kernel version and os version is as below</p>
  
  <pre><code>root@beaglebone:~# uname -a
  Linux beaglebone 3.8.13 #1 SMP Wed Sep 4 09:09:32 CEST 2013 armv7l GNU/Linux
  root@beaglebone:~# lsb_release -a
  Distributor ID: Angstrom
  Description:    Angstrom GNU/Linux v2012.12 (Core edition)
  Release:        v2012.12
  Codename:       Core edition
  </code></pre>