You're probably right. It would be helpful to say what the reason is, if it's no...

panick21_ · 2026-03-11T10:44:15 1773225855

I'm not a lawyer but I would assume its copyright. Kind of like API in software. In software somehow this does not apply most of the time. But it seems in hardware this is very real. But I would appreciate a lawyer jumping in.

I know for example that Berkley when thinking pre-RISC-V that they had a deal with Intel about using x86-64 for research. But they were not able to share the designs.

MarsIronPI · 2026-03-11T12:42:47 1773232967

I don't know why there aren't independent X86-64 manufacturers. Patents on the extensions maybe? But as I understand copyright, APIs can't be copyrighted so it's not that.

panick21_ · 2026-03-11T13:38:38 1773236318

The original ARM 32 stuff is clearly out of patents and is not being copied. And it doesn't require new extensions to be commercially viable.

userbinator · 2026-03-12T00:40:21 1773276021

and is not being copied

Are you sure, especially considering China?

I doubt there is any legal barrier, because there are a few existing projects with x86 cores on an FPGA, as well as some SoCs. Here's a 486: https://opencores.org/projects/ao486

panick21_ · 2026-03-12T08:49:46 1773305386

Ok if China is doing something only for China market that tells you something.

As for opencores, yes you can design them, but do any companies making commercial products sell them?