... but this is an embedded world. Almost every solution is so specific to the implementation at hand, especially those that have a hardware and/or SFR dependency. Based on that I feel that you are really making a mountain out of something that is rather simple.

Rather than try to save your self from fears of the support that you might have to give maybe your energy would way more well placed in writing a straightforward integration guide for the code you intend to supply and then be done with it. You could go a step further and make up simple configurations that fit to various 8051 families and tell folks if they need hand holding support beyond these examples that you'll offer that for a fee.

Personally if I were you I'd stop with the idea of having include files include other include files. This can really get to be a mess. You are actually best off if you design header files in a way that there is not little or no dependency between them (i.e. you could list the includes in any order at the top of the .C source files). Then put various things that would have tied .H files together into the specific source files where they specifically apply.

All that said I often find it useful to make one project specific header file that gets included into each and ever source file as the first header file in the list. Sometimes this may contain special information that is used inside other .H files such as a FIFO size or a buffer size.

Michael Karas