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Sorry if it’s a dumb question but how do you verify open source hardware? With software I have the code and I can build and deploy my own version. But how do yo

Sorry if it’s a dumb question but how do you verify open source hardware? With software I have the code and I can build and deploy my own version. But how do you do that with an open source CPU? I can read the code [0] but will the CPU as the physical object itself be the same? And the microcode running inside? 0, https://github.com/T-head-Semi/openc910 https://github.com/T-head-Semi/openc910

phendrenad2 3y ago
There really is no open-source hardware, not below the centimeter level. You have to trust some company to actually make your chip. I guess you could get an electron microscope and look at every transistor, but that's probably not realistic, even for most companies.
no_time 3y ago
You don’t. Open hardware is a positive for the company and almost entirely neutral for the consumer. I guess you could say It’s a positive for us too, since you are not subsidizing the ARM royalties with every tech purchase you make. But I wouldn’t bet on this cost cutting being passed down to us.
- imiric 3y ago
  > Open hardware is a positive for the company and almost entirely neutral for the consumer. I'd say it's the other way around, actually. And possibly a negative for the company in the current market, since it also needs to worry about competition based on their sources. The same as with open source software. It's entirely positive for the consumer, since it gives them the choice to choose between several manufacturers of the same design, or even manufacture the product themselves, if they have the capability. Open hardware is the end goal of the right to repair movement, in this sense. Even if the consumer doesn't have the capability to verify that the product they're using was built from open sources, they still retain their rights to modify, build and distribute their own versions. This is what "open" means. Note that this is the case with OSS too. It would be very difficult to prove that a specific binary was built from a specific source, but there's usually a degree of trust that the binaries provided by the developers were built from the same source the user has access to. The developers can also provide a mechanism for this to be validated, via checksums, reproducible builds, etc. I imagine that a similar mechanism might exist for hardware as well.
  - t-3 3y ago
    RISC-V isn't open hardware though, it's open architecture. Open architectures make it easier to design new chips. That isn't necessarily going to translate into cheaper or more easily repairable or more open-to-the-user products.
    - imiric 3y ago
      This isn't about RISC-V, but specifically about the BeagleV-Ahead board. They have an OSHW certification[1], and provide schematics and design documents[2]. Whether that will provide tangible benefits to the consumer is hard to say, as it will depend on how popular this design ends up being, among many other factors. Unlike with software, most end users don't have the capability to build their own versions, and have to rely on other manufacturers to do that. Still, this is surely a step in the right direction, and is more consumer-friendly than traditional closed architectures, platforms and products. [1]: https://certification.oshwa.org/us002535.html https://certification.oshwa.org/us002535.html [2]: https://git.beagleboard.org/beaglev-ahead/beaglev-ahead https://git.beagleboard.org/beaglev-ahead/beaglev-ahead
Qwertious 3y ago
It's less "how do you", and more "can you?". And according to the Novena open-hardware laptop guy, you can't: https://www.bunniestudios.com/blog/?cat=28 https://www.bunniestudios.com/blog/?cat=28 >Based on these experiences, I’ve concluded that open hardware is precisely as trustworthy as closed hardware. Which is to say, I have no inherent reason to trust either at all.
- RetroTechie 3y ago
  Thx for that link! Deserves its own HN post imho. It lays out the issues quite well. But... there's several things people here are forgetting: OSHW isn't just about chips, but also boards, case designs & possibly more. Those other things can be inspected easily. OSHW is also about supply security. Vendor folds? Take existing design & have another supplier manufacture it. US buyer doesn't trust Chinese vendor? Nothing stopping that buyer from taking design to say, a US or EU based manufacturer. This includes IC designs. OSHW allows modification & thus exchange of parts. So any part considered not 'open enough', can be exchanged for more acceptable one. Not saying anything about the practicality of this. But with closed designs these options don't exist or are much, much more difficult. And any vendor found to have tampered with an open design's manufacture, would see its reputation ruined (let's be honest, manufacturer would be the 'best' place to plant a backdoor, right?).
dragontamer 3y ago
I don't think that "open source cores" make sense outside of FPGA contexts. But FPGAs are incredibly closed and are poor performers for "just" CPU-emulation purposes. (FPGAs are best when you truly need custom hardware, and often are paired up with premade cores like Xilinx's Zynq + ARM FPGA+Core system). So... yeah. We're all beholden to the factories that make these chips. At best, we can design systems that port between factories but unless you plan to build your own chip factory, I don't think there's much of a solution (or need) for open source CPUs. I think there's a push for 180nm (ex: 2001-era) open source chip designs. But with many microprocessors available from 28nm or 40nm processes today (ex: 2012-era), I don't think the 180nm class chips stand a chance in any practical matter outside of weird space / radiation-hardened situations (180nm is better vs radiation apparently for reasons I don't fully understand). ------------ From "Beagleboard" perspective, their version of "open source" means freely available schematics and hardware reference designs, making it easy to build your own board and possibly even custom-boot your own versions of the Beagleboard. At least... the previous paragraph is based on "reputation" as opposed to true analysis. I'd have to actually go through the documentation and think about PCB design carefully to really know. For example, the "BeagleBone Black" was cloned by SeeedStudio and turned into "BeagleBone Green", a ground-up redesign of the board with the same chips. Proving that a 2nd company could in fact take these hardware schematics and rebuild a totally different project.
- unleaded 3y ago
  > I don't think the 180nm class chips stand a chance in any practical matter outside of weird space / radiation-hardened situations if it was good enough for the fastest PC processors in 2000 and the PS2 and gamecube, why wouldn't it be suitable for something like this?
  - dragontamer 3y ago
    Because chips supporting open-source software are available at the 28nm or 40nm level at much cheaper prices, higher performance, and lower power usage. I believe that 22nm is expected (in the long term) to become the cost-efficiency king, but its not an economic reality today yet. But 28nm and 40nm are the cost-efficiency kings today. So what ever could a 180nm design ever offer the typical consumer outside of radiation-hardening? And similarly, 5nm or 3nm server chips (like Xeon or EPYC) will always be at the forefront of power/performance/cost, you can't beat physics of shrinking transistors or the economics involved (though the most advanced node will need more-and-more volume to be cost-effective, as its become harder to build on these advance nodes). There's almost no reason to ever pick an ancient 180nm design on a low-run when millions of 40nm or 28nm chips are being made, and/or billions of 5nm superior chips are being made.
camel-cdr 3y ago
You can't, but you could create a test bench and verify that the behavior is cycle acurate the same as a simulated openc910. That's probably better than doing nothing. We know that openC910 isn't the exact same chip as the C910, as it doesn't include the draft vector extension.
pokwertf 3y ago
Since a CPU is the end-product, much like a binary compiled from open source project would be, open hardware is closer to "you can build it yourself" rather than "trust the already compiled version"
thebeardisred 3y ago
That's actually something we're working on right now in the RISC-V community. There are formal verifications that can be done at multiple hardware levels but the community needs to ratifiy more in the way of standards. After all... I assume wouldn't be comfortable until you can run Qualcomm's verifier (or a libre community supported option) on TI's chips, or a similar model of 'trust but verify'.
my123 3y ago
OpenC910 and XuanTie C910 are different cores. The latter has RVV 0.7.1 for example while the open-source version does not have it.

phendrenad2 3y ago

There really is no open-source hardware, not below the centimeter level. You have to trust some company to actually make your chip. I guess you could get an electron microscope and look at every transistor, but that's probably not realistic, even for most companies.

no_time 3y ago

You don’t. Open hardware is a positive for the company and almost entirely neutral for the consumer. I guess you could say It’s a positive for us too, since you are not subsidizing the ARM royalties with every tech purchase you make. But I wouldn’t bet on this cost cutting being passed down to us.

imiric 3y ago
> Open hardware is a positive for the company and almost entirely neutral for the consumer. I'd say it's the other way around, actually. And possibly a negative for the company in the current market, since it also needs to worry about competition based on their sources. The same as with open source software. It's entirely positive for the consumer, since it gives them the choice to choose between several manufacturers of the same design, or even manufacture the product themselves, if they have the capability. Open hardware is the end goal of the right to repair movement, in this sense. Even if the consumer doesn't have the capability to verify that the product they're using was built from open sources, they still retain their rights to modify, build and distribute their own versions. This is what "open" means. Note that this is the case with OSS too. It would be very difficult to prove that a specific binary was built from a specific source, but there's usually a degree of trust that the binaries provided by the developers were built from the same source the user has access to. The developers can also provide a mechanism for this to be validated, via checksums, reproducible builds, etc. I imagine that a similar mechanism might exist for hardware as well.
- t-3 3y ago
  RISC-V isn't open hardware though, it's open architecture. Open architectures make it easier to design new chips. That isn't necessarily going to translate into cheaper or more easily repairable or more open-to-the-user products.
  - imiric 3y ago
    This isn't about RISC-V, but specifically about the BeagleV-Ahead board. They have an OSHW certification[1], and provide schematics and design documents[2]. Whether that will provide tangible benefits to the consumer is hard to say, as it will depend on how popular this design ends up being, among many other factors. Unlike with software, most end users don't have the capability to build their own versions, and have to rely on other manufacturers to do that. Still, this is surely a step in the right direction, and is more consumer-friendly than traditional closed architectures, platforms and products. [1]: https://certification.oshwa.org/us002535.html https://certification.oshwa.org/us002535.html [2]: https://git.beagleboard.org/beaglev-ahead/beaglev-ahead https://git.beagleboard.org/beaglev-ahead/beaglev-ahead

Qwertious 3y ago

It's less "how do you", and more "can you?". And according to the Novena open-hardware laptop guy, you can't: https://www.bunniestudios.com/blog/?cat=28 https://www.bunniestudios.com/blog/?cat=28 >Based on these experiences, I’ve concluded that open hardware is precisely as trustworthy as closed hardware. Which is to say, I have no inherent reason to trust either at all.

RetroTechie 3y ago
Thx for that link! Deserves its own HN post imho. It lays out the issues quite well. But... there's several things people here are forgetting: OSHW isn't just about chips, but also boards, case designs & possibly more. Those other things can be inspected easily. OSHW is also about supply security. Vendor folds? Take existing design & have another supplier manufacture it. US buyer doesn't trust Chinese vendor? Nothing stopping that buyer from taking design to say, a US or EU based manufacturer. This includes IC designs. OSHW allows modification & thus exchange of parts. So any part considered not 'open enough', can be exchanged for more acceptable one. Not saying anything about the practicality of this. But with closed designs these options don't exist or are much, much more difficult. And any vendor found to have tampered with an open design's manufacture, would see its reputation ruined (let's be honest, manufacturer would be the 'best' place to plant a backdoor, right?).

dragontamer 3y ago

I don't think that "open source cores" make sense outside of FPGA contexts. But FPGAs are incredibly closed and are poor performers for "just" CPU-emulation purposes. (FPGAs are best when you truly need custom hardware, and often are paired up with premade cores like Xilinx's Zynq + ARM FPGA+Core system). So... yeah. We're all beholden to the factories that make these chips. At best, we can design systems that port between factories but unless you plan to build your own chip factory, I don't think there's much of a solution (or need) for open source CPUs. I think there's a push for 180nm (ex: 2001-era) open source chip designs. But with many microprocessors available from 28nm or 40nm processes today (ex: 2012-era), I don't think the 180nm class chips stand a chance in any practical matter outside of weird space / radiation-hardened situations (180nm is better vs radiation apparently for reasons I don't fully understand). ------------ From "Beagleboard" perspective, their version of "open source" means freely available schematics and hardware reference designs, making it easy to build your own board and possibly even custom-boot your own versions of the Beagleboard. At least... the previous paragraph is based on "reputation" as opposed to true analysis. I'd have to actually go through the documentation and think about PCB design carefully to really know. For example, the "BeagleBone Black" was cloned by SeeedStudio and turned into "BeagleBone Green", a ground-up redesign of the board with the same chips. Proving that a 2nd company could in fact take these hardware schematics and rebuild a totally different project.

unleaded 3y ago
> I don't think the 180nm class chips stand a chance in any practical matter outside of weird space / radiation-hardened situations if it was good enough for the fastest PC processors in 2000 and the PS2 and gamecube, why wouldn't it be suitable for something like this?
- dragontamer 3y ago
  Because chips supporting open-source software are available at the 28nm or 40nm level at much cheaper prices, higher performance, and lower power usage. I believe that 22nm is expected (in the long term) to become the cost-efficiency king, but its not an economic reality today yet. But 28nm and 40nm are the cost-efficiency kings today. So what ever could a 180nm design ever offer the typical consumer outside of radiation-hardening? And similarly, 5nm or 3nm server chips (like Xeon or EPYC) will always be at the forefront of power/performance/cost, you can't beat physics of shrinking transistors or the economics involved (though the most advanced node will need more-and-more volume to be cost-effective, as its become harder to build on these advance nodes). There's almost no reason to ever pick an ancient 180nm design on a low-run when millions of 40nm or 28nm chips are being made, and/or billions of 5nm superior chips are being made.

camel-cdr 3y ago

You can't, but you could create a test bench and verify that the behavior is cycle acurate the same as a simulated openc910. That's probably better than doing nothing. We know that openC910 isn't the exact same chip as the C910, as it doesn't include the draft vector extension.

pokwertf 3y ago

Since a CPU is the end-product, much like a binary compiled from open source project would be, open hardware is closer to "you can build it yourself" rather than "trust the already compiled version"

thebeardisred 3y ago

That's actually something we're working on right now in the RISC-V community. There are formal verifications that can be done at multiple hardware levels but the community needs to ratifiy more in the way of standards. After all... I assume wouldn't be comfortable until you can run Qualcomm's verifier (or a libre community supported option) on TI's chips, or a similar model of 'trust but verify'.

my123 3y ago

OpenC910 and XuanTie C910 are different cores. The latter has RVV 0.7.1 for example while the open-source version does not have it.