I can see specific parameters to use for GLOBAL_DEFINES in my makefile based on sample code, blogs, this forum, etc. but if I am looking for something specific I do not know where to look. E.g. how do I disable Ethernet?
Unfortunately, there is no such comprehensive list. I can pass on your request to the internal development team to come up with a list or a way to get them listed in IDE. You can try using the outline window for now to check the macros for each application, library and their makefiles. For ethernet, you can try PLATFORM_NO_GMAC=1