The version of the InterNiche TCP/IP stack that Altera ships is designed to work with uC/OSII. As such, if you aren't using uC/OSII for your application, the required source files won't even be found.
The InterNiche TCP/IP stack also supports superloop mode which does not require an OS. All of the designs that we have done using the InterNiche stack use superloop mode and thereby do not require uC/OSII. You have to do some minor modifications to the stack to get it to run in superloop mode.
Try these threads for more information:
http://forum.niosforum.com/forum/index.php?showtopic=8747 http://nioswiki.jot.com/wikihome/nichestack/%22super%20loop%22%20nichestack Jake