[Haskell] Building a library for C users

Hiya all, I'm trying to build a library that can be called from C code. The ghc manual implies that this can be done, but does not specify the compiler options that I need to throw at it, and into which files I should put initialisation/end routines. Does anyone know the magic I need to invoke to get ghc to produce for me (a) a header file, (b) preferably a dynamic library, put a static one if all else fails. Thanks Tom Davie