News New Mini PC Powered by China's Zhaoxin x86 CPU

JamesJones44

Great
Jan 22, 2021
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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?
 
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?
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.

Now how it's implemented, and maybe some secret sauce hardware that's unrelated to the ISA, is what's hidden behind licenses and IP laws or whatnot.

EDIT: It appears Zhaoxin is partly owned by VIA (see https://en.wikipedia.org/wiki/Zhaoxin)
 
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Drazen

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Dec 29, 2015
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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.
 
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.
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:
  • Emulators would be illegal, which they definitively are not. Emulators are simply a software implementation of the ISA.
  • It seems silly legally speaking that you can say "hexadecimal 0x0001 is code for addition and nobody else can use that code unless they pay me"
    • However I do believe you can't essentially copy an ISA's opcodes and behavior and call it something else. But if you rearrange enough parts around, especially core functionality, you can get away with it. Which is how the MOS 6502 was allowed to exist.
    • Although Zilog's Z80 is an interesting case because it's binary compatible with Intel's 8080. The only thing Intel didn't like about it was the usage of similar assembly language mnemonics... which Zilog changed and got away with.
  • There's nothing illegal with feeding the processor inputs and studying its outputs. And if the manufacturers are freely providing what inputs are acceptable and what the expected outputs are, that just makes clean-room reverse engineering easier.
 

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