Extending GLIP

Modules
	Circular Buffer

Detailed Description

GLIP is written in a way to make it easily extensible. Writing a new communication backend should be rather easy. GLIP also contains some helper functionality, such as an optimized circular buffer implementation, which can be reused in your code.

How to add a new backend

Adding a new backend requires only a couple of steps, which are listed below. In general, have a look at the existing backends for inspiration how things are done.

1. Create a new folder for your backend at src/sw/backend_YOURNAME. Make sure to consistently use YOURNAME as backend name everywhere. Inside this folder, add a backend_YOURNAME.c and a backend_YOURNAME.h file. It is usually a good idea to start by copying an existing implementation and removing all implementation parts. In the end your backend needs to implement all functions specified in glip_backend_if.
2. Add the backend to configure.ac. This usually includes searching for dependencies of the backend, e.g. required libraries or header files. The cypressfx2 backend serves as a good example for a backend with a library dependency found though pkgconfig, the tcp backend can be an example for a backend without any dependencies. Simply copy the code and adjust it for your backend. Don't forget to re-run autogen.sh after modifying the configure.ac file.
3. Add the backend to src/Makefile.am. Again, have a look at the existing backends for inspiration. Essentially, you need to list all source files of your backend and any libraries the backend requires (which might have been detected by pkgconfig during configure.
4. Register your backend in glip-private.h. The file contains notes on where to add your backend. At the top of the file, you need to conditionally include the backend_YOURNAME.h file, and further down, you need to add the BACKEND_YOURNAME macro to the glip_backends array.

That's it! Now you can run the configure script with --enable-YOURBACKEND, followed by make to see if your code compiles.