This directory contains the source of lwIP network stack and supporting 
source files for using lwIP under Xvisor as an optional network stack.

lwIP (lightweight IP) is a widely used open source TCP/IP stack designed 
for embedded systems. lwIP was originally developed by Adam Dunkels at 
the Swedish Institute of Computer Science and is now developed and maintained
by a world wide network of developers led by Kieran Mansley.

lwIP is licenced under a BSD-style license: http://lwip.wikia.com/wiki/License

For more info on lwIP visit following links:
http://savannah.nongnu.org/projects/lwip/
http://en.wikipedia.org/wiki/LwIP
http://lwip.wikia.com/wiki/LwIP_Wiki
http://lwip.wikia.com/wiki/Projects_that_use_lwIP

Currently, we use v1.4.1 of lwIP TCP/IP stack and we can easliy upgrade 
lwIP version due to its portable source code.

The detailed contents of this directory are as follows:
lwip-1.4.1/ - Unmodified source of lwIP v1.4.1 with fixes 
              to solve compile errors
port/       - Support source files for porting lwIP and netstack APIs
objects.mk  - Xvisor makefile to compile lwIP
README      - This file

Anytime you want to upgrade lwIP version <xxx>, you should do following:
* Replace directory lwip-1.4.1/ with new lwip-<xxx> directory
* Updated objects.mk to compile relevant source files of lwip-<xxx>
* Update this README for future references

