Custom database with EF

I've researched trying to figure out how I can implement DBProvider

to build DBContext

for a fully customizable database to no avail. Now this database uses standard SQL for communication, but the backend is incompatible with these providers, for example. SQL Server, Oracle, etc.

I want to be able to use Entity Framework to model and execute commands on this database, and also I want to use LINQ based queries directly from the created DBContext.

This database is divided and organized into several sub-modules that deal with different areas of schema and design.

How can I integrate current objects into a usable provider?

Any help is appreciated.