Apparently, the vpath magic in the lwip examples' Makefile requires
the lwip files to exist before the server is built. Thus, the build
script now calls make twice: First, to clone the lwip repositories,
and second, to create the actual server application.
When TESTS=yes is given, the scripts invokes the test driver from
the top build directory. Platform-specific actions hence must ensure
that they stay in that directory and keep the last exit code.
The build script invokes configure and make with different
parameters depending on the environment variables PLATFORM
and TESTS. PLATFORM currently must be one of 'posix', 'contiki', or
'lwip'. If TESTS is set to 'yes' or 'true', the option --enable-tests
will be passed to configure and tests/testdriver will be invoked
after configuration and make.
Olaf Bergmann