Xilinx Legal
in [FPGA]
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From: Austin Lesea on 30 Jan 2006 17:46 cs, Going from "using XDL" for some unspecified reason, to "open source" is a big step. Too big. There is nothing "open source" about any of Xilinx's software. Right now, the discussion has been about an ASCII representation of connections that Xilinx developed as a convenience (replaced an earlier format). XDL's use is only restricted by the agreements on the software that created it, and uses it (that we supply). It also specifically allows uses (for which it is intended) like someone writes a parser to generate a nice report from the XDL file (noted in the comments on XDL in our documentation). If you chose XDL to use as your intermediate language for your CS111 FPGA, I think it would be a curious choice, but one we would not have much claim to, as if you had your own tools to create it, and use it, test it; and you never used our tools, IP, or patents, why would we care? Austin
From: cs_posting on 30 Jan 2006 18:21 Austin Lesea wrote: > Going from "using XDL" for some unspecified reason, to "open source" is > a big step. Too big. For you perhaps, but open source code under a freedom-preserving license is perhaps the most likely variety of tool that volunteers might develop. The other alternative, closed software developed by those who hope to sell seats, and will license what they need from you, seems more in your comfort zone to date. > There is nothing "open source" about any of Xilinx's software. That's not what we're talking about, though I seem to recall some cygwin-ish files floating around in the install - but let's call that off topic. > Right now, the discussion has been about an ASCII representation of > connections that Xilinx developed as a convenience (replaced an earlier > format). Which if half of your comments are to believed is too encumbered to be of any use outside a private or closed source tool - or if the other half are to be believed, is available and harmless. > XDL's use is only restricted by the agreements on the software that > created it, and uses it (that we supply). It also specifically allows > uses (for which it is intended) like someone writes a parser to generate > a nice report from the XDL file (noted in the comments on XDL in our > documentation). Yes, but someone else can take that parser and use it as a starting point for something like reverse engineering. Unless the license terms _of the parser_ prevent that. But if they do, then parser (despite not being Xilinx software) is not a free and open tool. > If you chose XDL to use as your intermediate language for your CS111 > FPGA, I think it would be a curious choice, but one we would not have > much claim to, as if you had your own tools to create it, and use it, > test it; and you never used our tools, IP, or patents, why would we care? If it really talks the same XDL you do, then someone can use it as a bridge between a new language and your silicon (which you would like) or between your tools and someone else's silicon. The later would allegedly be a violation of your license terms, but not of the license terms of the proposed XDL tool - unless the XDL tool is not a free and open piece of software. If the proposed XDL tool is not a free and open piece of software, then some of the participants in this discussion aren't interested in writing it. We could have a whole other discussion about why, but the obvious reason is that it's too big a project to be worthwhile without input from many sources and the justification of many users.
From: fpga_toys on 30 Jan 2006 18:26 Austin Lesea wrote: > Going from "using XDL" for some unspecified reason, to "open source" is > a big step. Too big. > > There is nothing "open source" about any of Xilinx's software. This is the companies right, no matter how much we object. There has to be a business decision that open source is in the companies best interests ... which is where talking about this and lobbying might be of use. > Right now, the discussion has been about an ASCII representation of > connections that Xilinx developed as a convenience (replaced an earlier > format). Until a document shows up on the public web site, with equiv data to the XNF specifications ... file format and object definitions, it's a closed proprietary standard, that requires violating the ISE EULA NDA to make public any use of it. > XDL's use is only restricted by the agreements on the software that > created it, and uses it (that we supply). It also specifically allows > uses (for which it is intended) like someone writes a parser to generate > a nice report from the XDL file (noted in the comments on XDL in our > documentation). *IF* there were a public document like the XNF spec, this statement would be true. Today it is false, as no one has been able to find such a public document yet. > If you chose XDL to use as your intermediate language for your CS111 > FPGA, I think it would be a curious choice, but one we would not have > much claim to, as if you had your own tools to create it, and use it, > test it; and you never used our tools, IP, or patents, why would we care? With a public XDL format and library objects document, this is exactly what we hope for.
From: cs_posting on 30 Jan 2006 18:28 John Williams wrote: > What you've now created is a hybrid license, incompatible with the pure > GPL (ok, so you can't host it on sourceforge, no big deal). If someone > uses the tool to target an Altera part, then they are breaking the > conditions of their license and it is therefore immediately revoked. > > You would add a viral clause which makes sure that further refinements > of the tool are also covered by the same dual condition (GPL + Xilinx only). But what if someone figures out XDL by reverse engineering your tool, rather than Xilinx's software? How do you prohibit someone from reverse engineering (ie, reading and taking notes) open code?
From: John Williams on 30 Jan 2006 18:37
cs_posting(a)hotmail.com wrote: > John Williams wrote: > > >>What you've now created is a hybrid license, incompatible with the pure >>GPL (ok, so you can't host it on sourceforge, no big deal). If someone >>uses the tool to target an Altera part, then they are breaking the >>conditions of their license and it is therefore immediately revoked. >> >>You would add a viral clause which makes sure that further refinements >>of the tool are also covered by the same dual condition (GPL + Xilinx only). > > > But what if someone figures out XDL by reverse engineering your tool, > rather than Xilinx's software? How do you prohibit someone from > reverse engineering (ie, reading and taking notes) open code? > I don't know. Maybe it doesn't matter. The purpose of "though shalt only target Xilinx parts" is to keep Xilinx off your back. If someone reads your code and reimplements the XDL parser for Evil, instead of Good, maybe it's Xilinx problem to pursue, and not yours? John |