su password for beagle board

Hi all,

  I am running android on beagle board. by default the serial
connection minicom login as "su" and the commands are getting executed
nicely.

  But when I am running the same commands from my android application
and as application runs in the user mode, my commands could not get
executed...

  Is there any way to overcome this problem.....How can we set the
password on the board??

Thanks,
Asif