title: How is the default LED blinking implemented on the beaglebone black
body: <p>Are there any beaglebone or embedded linux experts here? 
  A general question on something I can't understand regarding the board when it is powered-on initially.</p>
  
  <p>The LEDs have a default blinking sequence. It is of course possible to change the behavior of the LEDs after startup by software, but on start-up , how is this default blinking sequence implemented?, and how could this be modified to be different on startup for example?</p>
  
  <p>Is this a process that gets started when Debian starts up?<br>
  If so, I can't see it when I type command "ps".<br>
  Thanks in advance</p>