Building lwIP ============= lwIP uses a CMake based build system. The CMake files in this project are designed to be included into your own CMake files. They are mainly variable definitions containing a list of source files and predefined static libraries to be linked against application code. 1) lwIP sources: src/Filelists.cmake provides file lists containing the lwIP core library. The file also contains two static libraries, lwipcore and lwipallapps, where you can link your app against. This is the file that is useful to all lwIP users. 2) Example applications: contrib/Filelists.cmake provides several file lists containing the example applications. The file also contains several static libraries for these example apps. This file is only useful for you, if you can use one of the examples in your application, which is normally not the case. 3) OS/platform port: Usually the OS port needs to be provided by the user. If a port to Linux, Windows or MacOS is useful for you, you can use contrib/ports/{win32, unix}/Filelists.cmake that contains file lists and libraries for these operating systems. VARIABLES ========= In all cases, you need to provide two variables. "LWIP_DIR" pointing to the lwIP directory Example: set(LWIP_DIR ${CMAKE_CURRENT_SOURCE_DIR}/externals/lwip) "LWIP_INCLUDE_DIRS" that contains the include base paths - for lwIP itself (${LWIP_DIR}/src/include) - for lwIP contrib if you use it (${LWIP_DIR}/contrib) - to a directory containing an OS port - to a directory containing lwipopts.h Example: set (LWIP_INCLUDE_DIRS "${LWIP_DIR}/src/include" "${LWIP_DIR}/contrib" "${LWIP_DIR}/contrib/ports/unix/port/include" "${LWIP_DIR}/contrib/examples/example_app" ) Putting it all together ======================= To get a working application, your CMake system needs to provide the variables described above, e.g. set (LWIP_DIR ) set (LWIP_INCLUDE_DIRS "${LWIP_DIR}/src/include" "${LWIP_DIR}/contrib" "/include" "" ) You may add some defines: set (LWIP_DEFINITIONS LWIP_DEBUG=1) Then include the filelists you need: include(${LWIP_DIR}/src/Filelists.cmake) include(${LWIP_DIR}/contrib/Filelists.cmake) Then, declare you executable: add_executable(my_app ) Add lwIP include dirs to your app: target_include_directories(my_app PRIVATE ${LWIP_INCLUDE_DIRS}) Link your app against the lwIP libs from the filelists you need: target_link_libraries(my_app lwipcontribapps lwipallapps lwipcore) Working example =============== Working build examples can be found in the contrib/ports/{win32, unix}/example_app subdirectory. To use them, create a build directory and call cmake with the lwIP root dir: - mkdir build - cd build - cmake - cmake --build The CMakeLists.txt will autoselect the correct port for your system. Makefile based build system =========================== lwIP also maintains file lists for Makefile-based build systems. Look for Filelists.mk files in the source tree. We try to maintain them, but lwIP's mainly focused build system is CMake.