Help me understand this better.
From what I have read online, since arm just licenses their ISA and each vendor’s CPU design can differ vastly from one another unlike x86 which is standard and only between amd and Intel. So the Linux support is hit or miss for arm CPUs and is dependent on vendor.
How is RISC-V better at this?. Now since it is open source, there may not be even some standard ISA like arm-v8. Isn’t it even fragmented and harder to support all different type CPUs?
TL;DR: While Intel had their heads shoved up their ass making the Itanium architecture, AMD made a 64-bit variant of x86 that was backward compatible with the older x86 ISA. Technology moved on, and amd64 was adopted while Intel kept trying and failing to push their binary-incompatible architecture.
Eventually, Intel had to give up and adopt AMD’s amd64 ISA. In exchange for letting them use it, Intel lets AMD use the older x86 ISA.
AMD were already using the x86 ISA long before amd64.
https://en.m.wikipedia.org/wiki/AMD
AMD were also second source for some other Intel logic chips before that deal.
I was only going for explaining why AMD still continues to have the license to the x86 instruction set in modern times, but I appreciate the added historical context to explain to others how they originally had the rights to use it.
Crazy!