In the Eclipse IDE Arduino Download Manager, I select Add, then I select Arduino AVR Boards as my platform. I then select OK and the platform does not add. I am plugged into the Sparkfun BlackBoard.
I’m afraid we don’t support the Eclipse IDE, but it is possible to program the blackboard with it. You might try the Eclipse forums to see if anyone over there is able to walk you through installing the packages needed to make it work. The link below will take you to those forums.