Use add_subdirectory() to include libipstack in your own CMake based application or operating system. You need to provide the kconfig executable either as file in BUILD_DIR/qconfig or via the variable KCONFIG_EXECUTABLE.
If you also use kconfig to configure your os or app, you may want to include buildsystem/ipstack.fm into the file you handle over to kconfig. You may use the build tool in buildsystem/merge_kconfig_input.
If you want a preselection (by adding relevant keys from a .config file before executing kconfig) for the ipstack, you need to add buildsystem/kconfig_output_default to your .config file. You may use the build tool in buildsystem/merge_kconfig_output to merge your defaults with ipstacks defaults. Place the .config output file from kconfig in KCONFIG_RESULT_FILE_DIR (usually the build dir) to avoid calling kconfig a second time.
If you want additional files to be considered by the aspectc++ compiler for the ipstack, for example if you want to add aspect files to manipulate the stack, set the variable IPSTACK_ADDITIONAL_SRC.