Looking at the cocobase website I find it hard to tell what the product does, so I can only talk about what jboss does.
jboss includes a persistence manager, JAWS, for cmp beans. By default, it can generate tables for your cmp beans, or use predefined tables, and in any case will map the beans to tables automatically. If you need more control over this process you can specify the ejb field - db column name mapping and the db column datatype declaratively in an xml file. There is a free tool xdoclet (formerly ejbdoclet) on sourceforge, developed I believe primarily by some jboss developers, that can generate most of the code and deployment descriptors needed for ejbs.
I don't know of any tools that help much with bmp. Note that ejb 2 support with local interfaces etc is nearing completion in the development version of jboss.