[ixp1200] How to get rid of Intel's MicroACE?

Hi, I just have an ixp1200 to develope some applications. Through Intel provides its MicroACE as an default framework for the development, there's some thing that can not fitted into it well; then, following MicorACE becomes painful. Yet, Intel doesn't provide any documents on how to get rid of MicroACE. There's not a clear document on the APIes, which can be used by the application to directly inject microcodes into microengines, and trigger the operation. Would anyone with such experiences give some hints? Regards. Irvin