plugins/modelbase/org.eclipse.datatools.modelbase.derby/plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>

<plugin>

  <extension point="org.eclipse.emf.ecore.generated_package">
    <package 
       uri = "http:///org/eclipse/datatools/modelbase/derby/derby.ecore" 
       class = "org.eclipse.datatools.modelbase.derby.DerbyModelPackage"
       genModel = "model/derby.genmodel" /> 
  </extension>

</plugin>