GSOC'16 project update - RTEMS LwIP integration

[Pavel Pisa]

Hello Sai Charan Sane and others,

I have included mainline lwIP as a submodule in src/lwip
of your repository. Then I have filterred our lwip-omk
  https://sourceforge.net/p/ulan/lwip-omk/ci/master/tree/
repository commits to include only ports commits there.
I have moved our ports to src/ports subdirectory of your
respository.

  https://github.com/sacha23/lwip-rtems-support

The TMS570 port and RTEMS OS adaptation should be
of main interrest to you now.

  lwip-rtems-support/src/ports/driver/tms570_emac
  lwip-rtems-support/src/ports/os/rtems

The NXP LPC drivers has been used only in systemless
setup till now because RTEMS includes LPC driver
for classic stack. But I want to test lwIP with LPC
driver under RTEMS some day as well.

Critical is to have equivalent of config system to
provide defines to include right C files, copy out right
headers and build configuration header file.

Our actual setup is based on OMK - https://rtime.felk.cvut.cz/omk/

The OMK files which are part of our port directory are included
in the lwip-rtems-support repository for now even (pass the filter).

  https://sourceforge.net/p/ulan/lwip-omk/ci/master/tree/ports/os/lwipopts.h
  https://sourceforge.net/p/ulan/lwip-omk/ci/master/tree/ports/os/Makefile.omk
       this one is responsible for generation of lwipconfig.h header file
  there are more of OMk files for other directories

But make rules and these receipts responsible for actual lwIP library
build are missing for now. Original there

  https://sourceforge.net/p/ulan/lwip-omk/ci/master/tree/Makefile.omk
  https://sourceforge.net/p/ulan/lwip-omk/ci/master/tree/Makefile.omk_include

It is necessary to decide which make system should be used.
I can try to adapt OMK lwIP rules to work with this new setup
to move project forward for now. But if some other mechanism how
to setup options, conditionalize list of build C files and options
for headers files is suggested/prepared then we can jump
directly to that solution.
Best wishes,

               Pavel