4 ms·

The thing about arm that's always troubled me, which I only see talked about infrequently, is the way it's licensed vs x86_64 chips. Arm chips are licensed in s

The thing about arm that's always troubled me, which I only see talked about infrequently, is the way it's licensed vs x86_64 chips. Arm chips are licensed in such a way that allows for a multitude of different proprietary configurations that all are essentially arm chips, but locked down at the whims of the manufacturers. I understand power usage is a big concern these days, but I can't help but feel this aspect of arm is greatly overlooked and that the push towards arm devices is also partially inspired by the ability to lock down chip designs to a greater capacity than x86_64 chips. Just look at the existing fragmentation among arm powered devices as is. I don't really like the thought of what an arm powered future could look like. I really wish I could remember what video it was, but I remember years ago watching the ceo of arm present a new chip with built in emulation technology, that theoretically, would have allowed multiple operating systems to run at once or something. I remember the person talking to him asked if he forsaw this as the future, and he just laughed and said oh no, no manufacturers would never dream of allowing this and furthermore they'll likely use this technology to further specialize and lockdown their chips. It may be personal bias, but since then and other things i've learned about arm, I've just had this lingering unease as to what them gaining dominance would mean to general computing.

Xixi 6y ago
The thing with x86_64 is that Apple/Amazon/Google/Samsung/Fujitsu/etc cannot license it. There are only two corporations with x86 licenses granted by Intel: AMD and VIA. These licenses are not transferable, and a even a badly managed acquisition could result in the license being revoked. So moving out of the x86/x86_64 world is really a no-brainer: why would all the electronic giants keep paying for x86 when they can get out of the de-facto duopoly? It seems that they are settling on ARM (Amazon Graviton, Fujitsu A64FX, Apple A12Z, etc.). It could have been another architecture, but it couldn't be x86_64. On the other hand, there are other architectures besides ARM and x86: RISC-V, OpenSPARC, etc. Maybe one of these would be better for developers who don't want to deal with the ARM landscape fragmentation.
- fiddlerwoaroof 6y ago
  X86, as I understand, has the advantage of a fairly widely implemented ISA that specifies all sorts of things about how other things on the motherboard communicate with each other and with the CPU
  - 737maxtw 6y ago
    > specifies all sorts of things about how other things on the motherboard communicate with each other and with the CPU That used to be true, but I dont know how true it is now. Once upon a time, ISA and ATA were both wired right to the bus. By the P3/Athlon era everything was probably on a super-io controller and or south bridge, but that communication towards the northbridge/CPU was over PCI or ever fancier links. But the clear cutting point to me is EFI. Most of the standards in how things communicate on older PCs was more based on the IBM BIOS. Early clones couldnt exist until that was nailed down. But... EFI replaces all of that with a new abstraction.
    - fiddlerwoaroof 6y ago
      I’m not a hardware person, really, but—even with EFI—my understanding is that x86 motherboards all implement standards that specify how the motherboard’s features can be accessed from software in a way that is fairly uncommon in ARM/MIPS/etc.
      - yjftsjthsd-h 6y ago
        Basically correct; the key bit is that x86 usually has a bus that can be enumerated by the OS. So you boot, and the OS can look around and see what hardware it has (and where it all is). On most ARM, the OS boots blind and you have to tell it (usually via device tree) what devices are attached and where.
        vertex-four 6y ago
        There's a spec for putting a device tree in an ARM chip's rom, the problem being that it's often wrong in some way, requiring device-specific corrections. Note, however, that there's a lot of "quirks" and similar device-specific corrections for x86 as well. These get presented to Microsoft by the manufacturer, and Linux gets to reverse-engineer them.
fit2rule 6y ago
Architecture is one thing, availability another. ARM is a lot more available on the global market, from multiple foundries. What I think is interesting is what this will do to the low-power x86 front, not just in terms of technical innovation but also availability. I'm perfect content building for x86, if it becomes as-available as the raspberry-pi class of devices ...

Xixi 6y ago

The thing with x86_64 is that Apple/Amazon/Google/Samsung/Fujitsu/etc cannot license it. There are only two corporations with x86 licenses granted by Intel: AMD and VIA. These licenses are not transferable, and a even a badly managed acquisition could result in the license being revoked. So moving out of the x86/x86_64 world is really a no-brainer: why would all the electronic giants keep paying for x86 when they can get out of the de-facto duopoly? It seems that they are settling on ARM (Amazon Graviton, Fujitsu A64FX, Apple A12Z, etc.). It could have been another architecture, but it couldn't be x86_64. On the other hand, there are other architectures besides ARM and x86: RISC-V, OpenSPARC, etc. Maybe one of these would be better for developers who don't want to deal with the ARM landscape fragmentation.

fiddlerwoaroof 6y ago
X86, as I understand, has the advantage of a fairly widely implemented ISA that specifies all sorts of things about how other things on the motherboard communicate with each other and with the CPU
- 737maxtw 6y ago
  > specifies all sorts of things about how other things on the motherboard communicate with each other and with the CPU That used to be true, but I dont know how true it is now. Once upon a time, ISA and ATA were both wired right to the bus. By the P3/Athlon era everything was probably on a super-io controller and or south bridge, but that communication towards the northbridge/CPU was over PCI or ever fancier links. But the clear cutting point to me is EFI. Most of the standards in how things communicate on older PCs was more based on the IBM BIOS. Early clones couldnt exist until that was nailed down. But... EFI replaces all of that with a new abstraction.
  - fiddlerwoaroof 6y ago
    I’m not a hardware person, really, but—even with EFI—my understanding is that x86 motherboards all implement standards that specify how the motherboard’s features can be accessed from software in a way that is fairly uncommon in ARM/MIPS/etc.
    - yjftsjthsd-h 6y ago
      Basically correct; the key bit is that x86 usually has a bus that can be enumerated by the OS. So you boot, and the OS can look around and see what hardware it has (and where it all is). On most ARM, the OS boots blind and you have to tell it (usually via device tree) what devices are attached and where.
      - vertex-four 6y ago
        There's a spec for putting a device tree in an ARM chip's rom, the problem being that it's often wrong in some way, requiring device-specific corrections. Note, however, that there's a lot of "quirks" and similar device-specific corrections for x86 as well. These get presented to Microsoft by the manufacturer, and Linux gets to reverse-engineer them.

fit2rule 6y ago

Architecture is one thing, availability another. ARM is a lot more available on the global market, from multiple foundries. What I think is interesting is what this will do to the low-power x86 front, not just in terms of technical innovation but also availability. I'm perfect content building for x86, if it becomes as-available as the raspberry-pi class of devices ...