Vulnerability hunting
From MILEDROPEDIA
This is a very hard way. you need to do reverse engineering of all Motorola boot loaders
For more information see here:
Security in Motorola Android Phones family
Here you can find useful things for the IDA Pro for droid reverse engineering: http://gitorious.org/droid/ida
Here you can find latest IDA databases of these boot loaders http://gitorious.org/droid/reversed