You can just grab the ISA documentation right on Intel's website and AMD's website. If it was freely (as in beer) available, I don't understand why you need a license to implement an x86 processor.I'm a little confused to be honest, do they hold a license to the x86 ISA? Or is this just doing it without permission?
That makes more sense to me now. I knew Intel was able to stop other companies from making x86 CPUs without licensing, so I wasn't sure how they were able to sell outside of China without Intel getting angry. Now that I understand they are/were part of VIA that makes more sense.
This looks like a confusion between what the ISA is (an abstraction of a computer) and the actual realization of it (the CPU core). I would still argue the ISA, with the exception of maybe some novel things, cannot be protected behind IP laws. Otherwise:ISA is proprietary and license must be aquired, paid. What is different between ARM and Intel is architecture. ARM sells (gives for free) it's core design (RTL) while Intel does not.
AMD and VIA bought ISA and developed their own cores, like Apple did with M1. Also in past AMD created x64 ISA and Intel bought it.
Chinese have cooperation with AMD and VIA - several Chinese companies have legal x86/x64 CPUs with custom or VIA cores. Of course VIA is out for long time while AMD does not sell Zen cores.