Encouraging reusable network hardware design

The NetFPGA platform is designed to enable students and researchers to build networking systems that run at line-rate, and to create re-usable designs to share with others. Our goal is to eventually create a thriving developer-community, where developers around the world contribute reusable modules and designs for the benefit of the community as a whole. To this end, we have created a repository of ldquoUser Contributed Designsrdquo at NetFPGA.org. But creating an ldquoopen-source hardwarerdquo platform is quite different from software oriented open-source projects. Designing hardware is much more time consuming-and more error prone-than designing software, and so demands a process that is more focussed on verifying that a module really works as advertised, else others will be reluctant to use it. We have designed a novel process for contributing new designs. Each contributed design is specified entirely by a set of tests it passes. A developer includes a list of tests that their design will pass, along with an executable set of tests that the user can check against. Through this process, we hope to establish the right expectations for someone who reuses a design, and to encourage sound design practices with solid, repeatable and integrated testing. In this paper we describe the philosophy behind our process, in the hope that others may learn from it, as well as describe the details of how someone contributes a new design to the NetFPGA repository.