It is not the bitstream per say that you want, but the full description of the Device Database (defining every programmable switch in the FPGA).<p>Somebody asked why are FPGA EDA tools so large. Well, this is the number one reason.<p>So, at the end of the day, the real reason why FPGA companies don&#x27;t open source their bitstream (and as I said, the actual database) is simply because it will be a major undertaking for them to document in any way that will actually make it possible for the community to use. An FPGA is NOT a processors so it not as easy to document as documenting an instruction set.<p>So, very hard to do, and not enough of a business justification to do so (combined with old school management that don&#x27;t really understand the value of open source). That is it.<p>BTW, it will actually be relatively doable to document the basic Logic Cell, but the problem is that in today&#x27;s modern FPAGs, the logic portion is a relatively small portion (when considering complexity) compared to the very complex I&#x2F;O interfaces.<p>I think the best you can hope for (and what I believe both X and A are moving towards) is a more flexible tool flow,  and heavy use of technologies like Partial Reconfiguration, which should allow you to build lots of tools and simply use the FPGA tools (mostly P&amp;R and Timing Analysis) as &quot;smaller&quot; black boxes, while allowing open source or third party to build higher level system integration tools (which IMO, is what is more needed today).