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?
The ISA guarantees that a program compiled for it can run on any of these vendor designs. For example native binaries for Android run on any SoC from any vendor with the ARM ISA compiled for. The situation is exactly the same as with x86, Intel and AMD. Their core designs are very different yet binaries compiled for x86 run on either Intel or AMD, and on any of their models, even across different architectures. E.g. a binary compiled for x86_64 would run on AMD Zen 2, as well as Intel Skylake, as well as AMD Bulldozer.
It’s better in that it’s free to use. Anyone making a chip implementing RISC-V doesn’t have to pay ARM or Intel for a license. Not that Intel sells them anyway.
The fragmentation issue might become a new problem. With that said we definitely want to move away from the only usable cores using ARM or x86, neither of which we can design and manufacture without the blessing of two corpos, one of which is a proven monopoly abuser.
How did AMD get the rights to build these CPUs? It is the only competitor it seems.
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.
Itanium also failed miserably in performance and everything else it set out to deliver. While being ridiculously expensive.
Crazy!
VIA also built x86 CPUs for some time, they have a license as well; the issue with modern x86_64 is though that basically, you need licenses from both AMD and Intel. They do have a cross-license agreement, but there’s no single point of contact for all licenses for a modern x86 CPU.
To sell into the US government in the 70s you had to ensure your parts could be sourced from a second company. That way, if you had supply problems, the government would just got to the second source.
AMD was a second source for the 8086.
So way back in what? the late 70’s or early 80’s, IBM decided they wanted to get into the microcomputer business. They didn’t want to throw a lot of money at it developing it in-house, so they slapped together a machine from off-the-shelf components to include an Intel CPU, after failing to get the attention of the guy who wrote CP/M they hired some little nobody software house called Microsoft to do the operating system which they licensed on a non-exclusive basis, and figured the copyright on their firmware (the BIOS) would keep the system proprietary. It didn’t. Compaq created and sold a compatible but non-infringing BIOS, which meant IBM had no legal standing to prevent anyone from building or selling machines 100% compatible with their line of PCs.
IBM had accidentally created an open standard, which wasn’t so good for IBM but great for customers. You could price shop. There was a certain security in “if this vendor quits, I can go with another vendor and keep my software and peripherals.” There were competitors to Microsoft’s MS-DOS even before Linux, you could get disk drives and such from multiple companies…only the CPU was truly proprietary to one company.
So as big businesses and governments started adopting these things and paying BIG bucks investing in computer infrastructure, hardware, software, personnel training etc. a lot of bigwigs started worrying about Intel’s future. What if this company goes bust, has a fire at a factory, puts out two whole generations of products that destroy themselves or whatever. Will that pull a rug out from under us? So Intel had to give AMD a license to manufacture x86 chips as a second source.
Add in a mention of Syrix here, a little company that sprung up also manufacturing x86 chips around the Pentium era who didn’t have a license from Intel, they reverse engineered and then sold non-infringing compatible CPUs, so there was briefly a third horse in that race.
AMD has served several different roles in the space; they’ve sold identical copies of Intel chips to the point they had both the Intel and AMD logo on them, they sold low-tier budget options, and on occasion they’ve actually out-done Intel at their own game.
They reverse-engineered themEdit: Huh, apparently I misremembered