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What does GPL mean for a chip design? I understand how it applies to the HDL, but I doubt that it obligates you have to open your code to users of physical chi

What does GPL mean for a chip design? I understand how it applies to the HDL, but I doubt that it obligates you have to open your code to users of physical chips.

dmoreno 5y ago
IANAL, but as far as I know it's very important it's GPLv3 which means the antitivoization clause, which means that hardware that uses this firmware must provide full source code and a way to let you use your own firmware. If somehow this code is not in a firmware... No idea.
- Taniwha 5y ago
  (this is a light derail but related) some of this design IS firmware - the lowest level bootstrap is encoded into an internal ROM - currently it's a very dumb bootstrap, a real implementation would boot from a number of possible sources. The sources are there on github. All the ARM systems you can buy today have a similar embedded boot loader - almost all of them do not release that source, because it's the root of their secure boot chain. IMHO this code should be public (but not the keys)
bragr 5y ago
Also IANAL, but as I understand it, the HDL would compile down to a sequence of gates, and presumably we'd treat that the same way as a binary - a "Non-Source Form" as the GPL calls it. So anyone that receives a copy of those gates (either as a binary blob for a FPGA, or pre-flashed on a FPGA, or made on actual silicon) would be entitled to the source as per GPL3 section 6 "Conveying Non-Source Forms". I don't think the GPL anti-tivoization clause has much bearing there other than presumably you'd have to provide the full tool chain that resulted in the final gates - presumably this would affect companies producing actual chips the most since you couldn't have any propriety optimization or layout steps in producing the actual chip design, though also no DRM for FPGAs (is that even a thing?)
Someone 5y ago
I guess you could argue that, if you bought a device with this CPU, you should be able to replace the CPU with one of your own that’s derived from this one. I think that’s the spirit of the GPL in a hardware context, but I don’t think it’s a given (by a long stretch) that courts would accept that argument. A somewhat clearer case would be if you bought a device that implements a GPL licensed design in a FPGA. I think you could argue such devices cannot disable the reprogrammability of the FPGA.
wmf 5y ago
It means "pay me to remove the GPL". It's fake GPL like MySQL and MongoDB.
- homarp 5y ago
  https://www.fsf.org/blogs/rms/selling-exceptions https://www.fsf.org/blogs/rms/selling-exceptions RMS wrote "I've considered selling exceptions acceptable since the 1990s, and on occasion I've suggested it to companies. Sometimes this approach has made it possible for important programs to become free software."
marcodiego 5y ago
AFAICS, it is the same as software: you changed and distributed; you have to provide your changes if asked to.
Taniwha 5y ago
Well (author here) - this is a private project - typically such a project would be very propriety - people don't get to show their work. But I'm looking to find someone to build this thing, it's been a while since I last built chips (last CPU I helped design never saw the light of day due to reason that had little to do with how well it worked). So I need a way to show it off, show it's real. So GPLing it is a great way to do that - as is showing up on HN (thanks to whoever posted this :-). In practice the RTL level design of a processor is only a part of making a real processor - a real VRoom! would likely have hand built ALUs, shifters, caches, register files etc those things are all in the RTL at a high level but are really different IP - likely they'd be entangled with GPL and a manufacturer might feel that to be an issue. However I'm happy to dual license (I want to get it built, and maybe get paid to do it). Also about half the companies building RISCVs are in China (I've been building open source hardware in China for a decade or so now, so I know there's lots of smart people there) - they have a real problem (in the West) building something like this - all the rumors about supply chain/etc stuff - having an open sourced GPL'd reference that's cycle accurate is a way help build confidence.
- Taniwha 5y ago
  One other comment about why GPLing something is important for some like me - publishing my 'secrets' are a great way to turn them into "prior art" - you read it here first, you can't patent it now - I can protect my ideas from becoming part of someone else's protected IP by publishing it. I spent a few years working on an x86 clone, I had maybe 10 (now expired) patents on how to get around stupidly obvious things that Intel had patented - (or around ways to get around ways to get around In tel that other's had patented) - frankly from a technical POV it was all a lot of BS, including my patents
  - webmaven 5y ago
    > One other comment about why GPLing something is important for some like me - publishing my 'secrets' are a great way to turn them into "prior art" - you read it here first, you can't patent it now - I can protect my ideas from becoming part of someone else's protected IP by publishing it. This is a great strategy! > I spent a few years working on an x86 clone, I had maybe 10 (now expired) patents on how to get around stupidly obvious things that Intel had patented - (or around ways to get around ways to get around In tel that other's had patented) - frankly from a technical POV it was all a lot of BS, including my patents It might be worthwhile to GPL implementations of those expired patents if they are at all likely to be useful. And perhaps then do a bit of procedural generation of various combinations of them for release under the GPL as well (because those would be newly patentable). Prior art FTW!

What does GPL mean for a chip design? I understand how it applies to the HDL, but I doubt that it obligates you have to open your code to users of physical chips.

dmoreno 5y ago

IANAL, but as far as I know it's very important it's GPLv3 which means the antitivoization clause, which means that hardware that uses this firmware must provide full source code and a way to let you use your own firmware. If somehow this code is not in a firmware... No idea.

Taniwha 5y ago
(this is a light derail but related) some of this design IS firmware - the lowest level bootstrap is encoded into an internal ROM - currently it's a very dumb bootstrap, a real implementation would boot from a number of possible sources. The sources are there on github. All the ARM systems you can buy today have a similar embedded boot loader - almost all of them do not release that source, because it's the root of their secure boot chain. IMHO this code should be public (but not the keys)

bragr 5y ago

Also IANAL, but as I understand it, the HDL would compile down to a sequence of gates, and presumably we'd treat that the same way as a binary - a "Non-Source Form" as the GPL calls it. So anyone that receives a copy of those gates (either as a binary blob for a FPGA, or pre-flashed on a FPGA, or made on actual silicon) would be entitled to the source as per GPL3 section 6 "Conveying Non-Source Forms". I don't think the GPL anti-tivoization clause has much bearing there other than presumably you'd have to provide the full tool chain that resulted in the final gates - presumably this would affect companies producing actual chips the most since you couldn't have any propriety optimization or layout steps in producing the actual chip design, though also no DRM for FPGAs (is that even a thing?)

Someone 5y ago

I guess you could argue that, if you bought a device with this CPU, you should be able to replace the CPU with one of your own that’s derived from this one. I think that’s the spirit of the GPL in a hardware context, but I don’t think it’s a given (by a long stretch) that courts would accept that argument. A somewhat clearer case would be if you bought a device that implements a GPL licensed design in a FPGA. I think you could argue such devices cannot disable the reprogrammability of the FPGA.

wmf 5y ago

It means "pay me to remove the GPL". It's fake GPL like MySQL and MongoDB.

homarp 5y ago
https://www.fsf.org/blogs/rms/selling-exceptions https://www.fsf.org/blogs/rms/selling-exceptions RMS wrote "I've considered selling exceptions acceptable since the 1990s, and on occasion I've suggested it to companies. Sometimes this approach has made it possible for important programs to become free software."

marcodiego 5y ago

AFAICS, it is the same as software: you changed and distributed; you have to provide your changes if asked to.

Taniwha 5y ago

Well (author here) - this is a private project - typically such a project would be very propriety - people don't get to show their work. But I'm looking to find someone to build this thing, it's been a while since I last built chips (last CPU I helped design never saw the light of day due to reason that had little to do with how well it worked). So I need a way to show it off, show it's real. So GPLing it is a great way to do that - as is showing up on HN (thanks to whoever posted this :-). In practice the RTL level design of a processor is only a part of making a real processor - a real VRoom! would likely have hand built ALUs, shifters, caches, register files etc those things are all in the RTL at a high level but are really different IP - likely they'd be entangled with GPL and a manufacturer might feel that to be an issue. However I'm happy to dual license (I want to get it built, and maybe get paid to do it). Also about half the companies building RISCVs are in China (I've been building open source hardware in China for a decade or so now, so I know there's lots of smart people there) - they have a real problem (in the West) building something like this - all the rumors about supply chain/etc stuff - having an open sourced GPL'd reference that's cycle accurate is a way help build confidence.

Taniwha 5y ago
One other comment about why GPLing something is important for some like me - publishing my 'secrets' are a great way to turn them into "prior art" - you read it here first, you can't patent it now - I can protect my ideas from becoming part of someone else's protected IP by publishing it. I spent a few years working on an x86 clone, I had maybe 10 (now expired) patents on how to get around stupidly obvious things that Intel had patented - (or around ways to get around ways to get around In tel that other's had patented) - frankly from a technical POV it was all a lot of BS, including my patents
- webmaven 5y ago
  > One other comment about why GPLing something is important for some like me - publishing my 'secrets' are a great way to turn them into "prior art" - you read it here first, you can't patent it now - I can protect my ideas from becoming part of someone else's protected IP by publishing it. This is a great strategy! > I spent a few years working on an x86 clone, I had maybe 10 (now expired) patents on how to get around stupidly obvious things that Intel had patented - (or around ways to get around ways to get around In tel that other's had patented) - frankly from a technical POV it was all a lot of BS, including my patents It might be worthwhile to GPL implementations of those expired patents if they are at all likely to be useful. And perhaps then do a bit of procedural generation of various combinations of them for release under the GPL as well (because those would be newly patentable). Prior art FTW!