So Xilinx, is XDL and related libraries an available open source interface?

Started by January 26, 2006
So the question to Xilinx is, will Xilinx release the NDA restrictions
on XDL, and the associated library interfaces so that open source tools
can legally target ISE supported FPGAs?

It's pretty clear that most of the regulars here, just assume that XDL
and the associated libraries, are an open interface, and think it's ok
to ignore the IP restrictions in the ISE license. The legaleze says
otherwise.

So how about a clear definative legal statement about what are legal
ISE interfaces for open source development.

fpga_toys@yahoo.com wrote:
> So the question to Xilinx is, will Xilinx release the NDA restrictions > on XDL, and the associated library interfaces so that open source tools > can legally target ISE supported FPGAs? > > It's pretty clear that most of the regulars here, just assume that XDL > and the associated libraries, are an open interface, and think it's ok > to ignore the IP restrictions in the ISE license. The legaleze says > otherwise. > > So how about a clear definative legal statement about what are legal > ISE interfaces for open source development. >
I believe that it is established copyright law that SW interface specs are not protectable elements although there appear to be some gray areas. This seems to be a good write up from 1997 http://www.fenwick.com/docstore/publications/IP/IP_Articles/Baystate_Holding.pdf In any case here is the output of the XDL tool in ISE 8.1i unix> xdl -help Release 8.1i - xdl I.24 Copyright (c) 1995-2005 Xilinx, Inc. All rights reserved. Xdl is a single tool with 3 fundamental modes: * Report Device Resource Information * Convert NCD to XDL (ncd2xdl) * Convert XDL to NCD (xdl2ncd) Report generates a report of the physical resources available for a specific part. Ncd2xdl reads in an NCD file and generates an ASCII XDL file. Xdl2ncd reads in an XDL file and generates an NCD file. XDL is also a fully featured Physical Design language that provides direct read and write access to Xilinx's proprietary Native Circuit Description (NCD). This access enables all users to write tools to address their individual FPGA design needs. The XDL tool explicitly states that you are allowed to create tools that use the output of NCD2XDL or tools that create input for XDL2NCD. This use of course is restricted to use for Xilinx devices per the ISE 8.1i EULA. If you want to make a tool that writes XDL or a tool that does a read/modify/write using XDL for Xilinx devices open source go ahead. We have released application notes that explain how to use XDL to modify elements in a design. Some companies like Hier Design created and marketed their own tools using this interface. We liked the Hier Design tool so much we bought the company. I don't know what you mean by "NDA restrictions on XDL". I can't find any reference to a NDA documentation. Ed
<fpga_toys@yahoo.com> schrieb im Newsbeitrag 
news:1138297173.649950.136370@g14g2000cwa.googlegroups.com...
> So the question to Xilinx is, will Xilinx release the NDA restrictions > on XDL, and the associated library interfaces so that open source tools > can legally target ISE supported FPGAs? > > It's pretty clear that most of the regulars here, just assume that XDL > and the associated libraries, are an open interface, and think it's ok > to ignore the IP restrictions in the ISE license. The legaleze says > otherwise. > > So how about a clear definative legal statement about what are legal > ISE interfaces for open source development. >
Hi mr fpga_toys, you are constantly talking about NDA restricted XDL documents, as if you have signed an NDA with Xilinx and received special documents under that NDA agreement, in wich case its better for you that read those NDA agreements (signed by you and Xilinx) over again. If you have not signed such agreements then stop talking about NDA in this context. As of your Question to Xilinx - do not expect an reply as it totally unclear what you are actually asking as you have not defined that. In the form you asked your question it would deserve a "NO" as replay from any entity that has any understanding of legal matters. Xilinx can not say YES to your question. Well you probably know that yourself. So what are you trying to achive with your push? Antti
Ed McGettigan wrote:
> I believe that it is established copyright law that SW interface > specs are not protectable elements although there appear to be > some gray areas.
Software copyrights yes, but Xilinx claims a business contract license to protect IP in the release ... that is different law, and to violate the license is breach of contract.
> The XDL tool explicitly states that you are allowed to create tools > that use the output of NCD2XDL or tools that create input for XDL2NCD. > This use of course is restricted to use for Xilinx devices per the > ISE 8.1i EULA.
It is this "restricted to use for Xilinx devices" that violates every open source license, and which as a developer using BSD licenses that we can not accept (nor does any other accepted open source license). Be cause of this restriction, there is no forum where the software can be released, as it's impossible to acertain that the recipient is also bound by the Xilinx license terms. Open source requires that no restrictions be placed on the distribution, other than governmental. So read the EULA carefully, as the business contract language requires that you protect the IP assets you aquire as part of the license ... as they are trade secret and proprietary ... not public domain, and free to distribute.
On 2006-01-26, Antti Lukats <antti@openchip.org> wrote:
><fpga_toys@yahoo.com> schrieb im Newsbeitrag > news:1138297173.649950.136370@g14g2000cwa.googlegroups.com... >> So the question to Xilinx is, will Xilinx release the NDA restrictions >> on XDL, and the associated library interfaces so that open source tools >> can legally target ISE supported FPGAs? >> >> It's pretty clear that most of the regulars here, just assume that XDL >> and the associated libraries, are an open interface, and think it's ok >> to ignore the IP restrictions in the ISE license. The legaleze says >> otherwise. >> >> So how about a clear definative legal statement about what are legal >> ISE interfaces for open source development. >> > > you are constantly talking about NDA restricted XDL documents, as if you > have signed an NDA with Xilinx and received special documents under that NDA > agreement, in wich case its better for you that read those NDA agreements > (signed by you and Xilinx) over again. If you have not signed such > agreements then stop talking about NDA in this context.
The conservative assumption is that the EULA we all click when we install ISE is a valid document, and it has NDA-like clauses. The poster has clearly read that NDA very carefully. If you live in a country where such agreements are non-binding, let us know here. Then software developers in that country can proceed without fear -- until Xilinx stops exporting chips and software to that country for the same reason.
> As of your Question to Xilinx - do not expect an reply as it totally unclear > what you are actually asking as you have not defined that.
It's clear to me. Are you being willfully disingenuous? Well, maybe some clarification should be made of the phrase "associated library interfaces".
> In the form you > asked your question it would deserve a "NO" as replay from any entity that > has any understanding of legal matters. Xilinx can not say YES to your > question. Well you probably know that yourself. So what are you trying to > achive with your push?
In the short run, maybe the regulars will admit that XDL can not currently be considered an open interface. In the long run, maybe we can pressure Xilinx to remove NDA restrictions on information contained in XDL data files, to permit open source code to monkey with FPGA internals (without fear of being JHDLBits-ized). Presumably that means Xilinx's engineers and lawers have to have a serious talk, since a Xilinx lawyer can hardly be expected to say "YES" to a request he doesn't understand. Only after this is resolved, can the regulars here go back to telling people who want to make bitstreams with open source software to use XDL instead. - Larry
"Ed McGettigan" <ed.mcgettigan@xilinx.com> schrieb im Newsbeitrag 
news:drb64u$nga5@cliff.xsj.xilinx.com...
> fpga_toys@yahoo.com wrote: >> So the question to Xilinx is, will Xilinx release the NDA restrictions >> on XDL, and the associated library interfaces so that open source tools >> can legally target ISE supported FPGAs? >> >> It's pretty clear that most of the regulars here, just assume that XDL >> and the associated libraries, are an open interface, and think it's ok >> to ignore the IP restrictions in the ISE license. The legaleze says >> otherwise. >> >> So how about a clear definative legal statement about what are legal >> ISE interfaces for open source development. >> > > I believe that it is established copyright law that SW interface > specs are not protectable elements although there appear to be > some gray areas. This seems to be a good write up from 1997 > http://www.fenwick.com/docstore/publications/IP/IP_Articles/Baystate_Holding.pdf > > In any case here is the output of the XDL tool in ISE 8.1i > > unix> xdl -help > Release 8.1i - xdl I.24 > Copyright (c) 1995-2005 Xilinx, Inc. All rights reserved. > > Xdl is a single tool with 3 fundamental modes: > > * Report Device Resource Information > * Convert NCD to XDL (ncd2xdl) > * Convert XDL to NCD (xdl2ncd) > > Report generates a report of the physical resources > available for a specific part. > > Ncd2xdl reads in an NCD file and generates an ASCII XDL file. > > Xdl2ncd reads in an XDL file and generates an NCD file. > > XDL is also a fully featured Physical Design language that > provides direct read and write access to Xilinx's proprietary > Native Circuit Description (NCD). This access enables all > users to write tools to address their individual FPGA > design needs. > > The XDL tool explicitly states that you are allowed to create tools > that use the output of NCD2XDL or tools that create input for XDL2NCD. > This use of course is restricted to use for Xilinx devices per the > ISE 8.1i EULA. > > If you want to make a tool that writes XDL or a tool that does > a read/modify/write using XDL for Xilinx devices open source > go ahead. > > We have released application notes that explain how to use XDL to > modify elements in a design. Some companies like Hier Design created > and marketed their own tools using this interface. We liked the > Hier Design tool so much we bought the company. > > I don't know what you mean by "NDA restrictions on XDL". I can't > find any reference to a NDA documentation. > > Ed
Hi Ed, I wasnt quite sure if there are actual XDL documentation under NDA so I have replied (several replies in other treads) based on my best knowledge, eg stating that is OK to dvelop tool that use or generate XDL, well good to have that confirmed one more time. My reply to mr fpga_toys original post was to his question in general where he messes up XDL and interface and libraries and ISE and seems to request to opensource everything that is needed to generate bitstreams for Xilinx devices in general - at least that is how I did understand his question, and answer to the question int that form is defenetly no. As extension to XDL I belive the .LL file are also 'legal' source of information about Xilinx bitstreams so that 3rd parties can develop software and utilities that either patch bitstreams or perform partial reconfiguration or use readback features. So the use of XDL and LL files is defenetly sufficent to create different type of tools that can target Xilinx FPFA very close to the actualy physical implementation level. And I was and am sure that any such tools (of professional quality) would be welcomed by Xilinx as they do provide additional features and functionality for the users of Xilinx FPGA's. Antti
Antti Lukats wrote:
> As extension to XDL I belive the .LL file are also 'legal' source of > information about Xilinx bitstreams so that 3rd parties can develop > software and utilities that either patch bitstreams or perform > partial reconfiguration or use readback features.
The format of the file is useless without also being able to specify objects proprietary to Xilinx, and not part of the XDL format itself The real problem, is that all the licenses do not allow open source, and are restricted to your own development because the license doesn't specfically grant distribution rights of derived IP. The whole "patch bitstreams" is where you quickly get into IP outside the XDL format.
> And I was and am sure that any such tools (of professional quality) > would be welcomed by Xilinx as they do provide additional > features and functionality for the users of Xilinx FPGA's.
But not open source as long as the xilinx only restriction is in place. And certainly not on sourceforge, or other widely used public distribution point.
<fpga_toys@yahoo.com> schrieb im Newsbeitrag 
news:1138304609.649172.148320@z14g2000cwz.googlegroups.com...
> > Antti Lukats wrote: >> As extension to XDL I belive the .LL file are also 'legal' source of >> information about Xilinx bitstreams so that 3rd parties can develop >> software and utilities that either patch bitstreams or perform >> partial reconfiguration or use readback features. > > The format of the file is useless without also being able to specify > objects proprietary to Xilinx, and not part of the XDL format itself > > The real problem, is that all the licenses do not allow open source, > and are restricted to your own development because the license > doesn't specfically grant distribution rights of derived IP. > > The whole "patch bitstreams" is where you quickly get into IP outside > the XDL format. > >> And I was and am sure that any such tools (of professional quality) >> would be welcomed by Xilinx as they do provide additional >> features and functionality for the users of Xilinx FPGA's. > > But not open source as long as the xilinx only restriction is in place. > And certainly not on sourceforge, or other widely used public > distribution > point. >
and you mr fpga_toys are still an ..... ...... (everyone please fill in the blanks) Antti PS I self-censored my previous response to mr fpga_toys.
Antti Lukats wrote:

> > > and you mr fpga_toys are still an ..... ...... > (everyone please fill in the blanks) > > Antti > > PS I self-censored my previous response to mr fpga_toys. > >
Antti, Time to stop feeding the troll. We've given Mr. FPGA_toys the information about the hooks he needs to work within the framework of the xilinx tools. He's obviously not going to be happy unless they decide to make the entire tool chain open source. I'm not sure I understand why he is on this crusade. One doesn't need open source in order to read and write to the XDL chain. Xilinx encourages third party tools using XDL, as evidenced by the text at the beginning of an XDL file as well as the statement here on the news group by Ed McGettigan. I've come to the conclusion that MrFPGA is not looking for a solution, rather he is simply trolling. We've offered a solution, but he continues to use misdirection to try and poke holes in it because it doesn't meet his desire for totally open source. He also claims any XDL tools he creates cannot be distributed, which is bunk. He can't distribute Xilinx tools or IP, but he can certainly distribute a tool that talks to the xilinx tools through a published ascii interface that has the permission to use it printed right in every file generated by it. I think XDL is a very reasonable approach by Xilinx to offer hooks into its tools without having to give away the farm. JHDLbits, as I understand it (not sure where MrFPGA is getting his info, I think he's making a lot of it up), used information directly supplied by Xilinx under NDA, and included some of that information in the distribution, which was a violation of the NDA. XDL is provided under an end user license agreement, not an NDA. Making a tool to interface to it, from what I can see does not violate any terms of the EULA, provided you don't include the xilinx tools with any distributions of your XDL tool.
Ray Andraka wrote:
> One doesn't need open source in order to read and write to the XDL > chain. Xilinx encourages third party tools using XDL, as evidenced by > the text at the beginning of an XDL file as well as the statement here > on the news group by Ed McGettigan.
The point Ray, is that no one can use XDL in open source tools. The XIlinx license restricts all use to Xilinx only product, which specificaly prevents including it in a tool that supports multiple vendors. It indirectly prevents any public distribution of an XDL tool since you can not enforce the license provisions. The FpgaC team CAN NOT INCLUDE XDL in it's open source project. The request was not to have Xilinx release sources to it's tools. The request is for Xilinx to relax this crippling restriction which prohibits open source use of XDL and the related library object documentation.