Relative path support for SOPC builder and QIP files

One of the nice features in more recent versions of the software is the ability to create your own component libraries for SoPC Builder and the Nios tools. You create a ".ipx" file. This file can reference components located literally anywhere. Even more, you can make a ".ipx" library file that contains nothing more than a relative reference to another ".ipx" file which contains the actual components.

So, what we do:

1 - Put our custom components somewhere, doesn't matter where.

2 - Create a ".ipx" library file for our custom components. This is done using the "ip-make-ipx" program.

http://www.altera.com/literature/hb/qts/qts_qii54004.pdf

3 - Create another ".ipx" library file in the same folder where our SoPC Builder system is located. This ".ipx" file does nothing more than reference the first ".ipx" file which actually contains our components. Here is an example:

<library>
   <path path="../../../common/components.ipx" />
</library>

SoPC builder will scan its local folder for components and libraries. It will see our little ".ipx" file which will refer it to a common folder, read the "components.ipx" file and see all of our custom components. This works for both hardware and software components.

Jake