Extension documentation and manual

[kgf]

I am not very sure what it is you want. Note that various different PULP projects make use of available custom extension encoding space and use them differently. Are you talking about a specific core, specific instructions? Are you interested in porting a compiler to run with one of our cores? are you designing your own extensions and want to see what we did?

You mention cv32e40p, that is one of our earlier cores that is now being maintained by OpenHW with much better documentation and verification, we also frequently use this core.