Dear community,

Let’s just say I’m a country that wants to create my own CPU only using knowledge/tech/techniques that are in the open and nothing proprietary. When I said CPU, let’s just say something that can run a C program, and eventually the linux kernel.

Is creating one out of publicly accessed knowledge and resources even possible, and how minuscule the tolerance need to be? Is there even a successful open CPU project out there?

I’m asking this because of an anxiety that I have when knowing only several companies in the world know how to create a CPU.

  • IrritableOcelot@beehaw.org
    3·
    3 days ago

    There are a couple of further questions to be able to answer this best. First, when you say using only tech that is in the open, nothing proprietary, how strictly do you mean that? Historically, what Chinese foundries have done is buy a fab line far enough from the leading edge to not be questioned, then use that as a starting point for working towards smaller nodes. If thats allowed, it would be fairly trivial, 40 nm doesnt perform that badly.

    If you want the equivalent of “open-source” fab equipment, as far as I know that has never existed. In better news, if you go back to DUV/immersion lithography, its not just ASML manufacturing lithography, Nikon and Canon were still in the game, so power was less centralized.

    Second, what is the actual goal? If it’s just compute, no big deal. As long as you can write a C compiler for your architecture (or use RISC-V as other folks have mentioned) getting the Linux kernel running shouldn’t be too hard. However, you’re going to have to deal with manually modifying the firmware of any peripherals you want to run – PCIe devices, USB, I2C, etc. Not a firmware engineer, so I have no idea how hard it would be, but this is one of the things that’s been holding back Linux on Arm over the years.

    All in all, depending on how strict you want to be, it could be anywhere between slightly difficult and effectively impossible.

    • tengkuizdihar@programming.devOP
      1·
      2 days ago

      Now about that fab line, is that still protected under a secrecy license? What’s stopping the Chinese from making their own fab line besides the ASML monopoly?

      • IrritableOcelot@beehaw.org
        2·
        2 days ago

        Well, first of all China does make lithography equipment (for instance, Shanghai Micro Electronics Equipment, who are currently at 28 nm). There are a couple of others iirc, and they typically got started by licensing lithography technology from Japanese companies and then building on it.

        The issue is mostly one of economics – fabs want higher-resolution lithography as soon as possible, and they only buy it once, which means that the first company to develop new litho technologies takes the lions share of the revenue. If you’re second to the technology, or are more than half a dozen nodes behind like SMEE is, theres not a lot of demand because there are fabs full of litho machines from when that node was new, and theres not as much demand for them anymore.

        The issue with a new company making leading edge nodes is the incredible R&D and development cost involved. Nikon, Canon, and ASML shared the market when they all started developing EUV tech, and it took ASML 15+ years to develop it! Canon and Nikon teamed up, spent tens of billions of dollars on R&D, and dropped out once they realized they couldn’t beat ASML to market because there wouldn’t be enough market left for them to make their money back.

        If you want to learn more about the history of the semiconductor industry, I recommend the Asianometry YouTube channel!