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There is no such "do wtf you want" license. The ARM architectural license allows licensees (like Apple, Cavium, Samsung, and others) to implement CPUs that comp

There is no such "do wtf you want" license. The ARM architectural license allows licensees (like Apple, Cavium, Samsung, and others) to implement CPUs that comply with the architecture. Some things are off-limits, like custom instructions. Apple broke those rules. They probably got away with doing that as a "special exception" under the understanding that they were doing so for "embedded" use cases, i.e. iOS devices that will only ever run iOS, but now that their designs are in an open platform (M1), things have changed, and ARM is not happy.

monocasa 6y ago
Apple literally designed large parts of AArch64. There's no do wtf you want license that you can go out and buy, but Apple has one none the less from the sheer fact that it's partially their's to begin with and they negotiated it with ARM before AArch64 was even a twinkle in their eyes. ARM probably has some trademark mechanisms that they could in some world use to enforce compliance from Apple, but Apple has been super duper careful to refer to it as Apple Silicon rather than ARM.
skissane 6y ago
> There is no such "do wtf you want" license How do you know? ARM's license agreements with Apple are confidential and just about nobody knows what's actually in them (and the few who have seen them aren't allowed to talk about it.) The standard terms which ARM offers to its other customers may be quite different from the terms it has negotiated with Apple. Apple is a customer with unique clout and leverage, which means they can extract terms in negotiations which other customers may not be able to. If ARM offers Apple (or any other customer) "special terms", it wants to keep that fact confidential, so that other customers who have the (less generous) standard terms don't start pressuring for special terms for them as well.
- marcan_42 6y ago
  I know, because Apple went through the trouble of close-sourcing the M1 bring-up code in XNU source dumps... because it suddenly contains secret new instructions, while until now ARM XNU builds were largely public. These instructions enable an entire new set of parallel execution modes, among other things, to run more protected kernel code. Completely nonstandard stuff. Also, Apple somehow managed to push custom kernel support to the documentation of kmutil, but not the actual binary, until several macOS releases later. That would only happen if the latter got pulled for some extraneous reason. I've been working on this since December; the entire situation is all showing signs pointing straight at ARM's lawyers having gotten involved to some extent.
  - monocasa 6y ago
    The kmutil stuff sounds way more like they cut it at the last second for some QA issue, but the documentation tech writers are a different team and that part was missed. They wouldn't have figured out issues with lawyers this quickly. The bring up stuff could be explained by being scared about some patent nonsense.
  - skissane 6y ago
    I think there is another explanation for this than "they are breaking ARM's rules and either trying to hide it or getting in trouble" It is: "They are following ARM's special rules for Apple only but they aren't allowed to tell anyone that those special rules for Apple only exist" They might decide to leave certain processor extensions undocumented, even close source code which uses them, because they are worried disclosing them would implicitly reveal the existence of the "special rules for Apple", possibly violating the confidentiality clauses of the ARM-Apple contract containing those special rules. So I still don't see how you know that "There is no such 'do wtf you want' license", when the behaviour you describe is compatible with their being one, but its existence being secret
    - marcan_42 6y ago
      That's what I said: that they got a special exemption (which is not part of ARM's official license offering) to allow them to do this for embedded use cases (iOS devices), which implied that they wouldn't be documenting or having other people use these instructions. The problem is that the M1 threw a wrench in the works because now suddenly running non-Apple code that can use these instructions is allowed, and everyone else can see that they exist, so suddenly the existence of that special exemption is public.
      - skissane 6y ago
        > that they got a special exemption (which is not part of ARM's official license offering I agree except I'd say that it is part of ARM's official license offering, but only if your name is "Apple".
teclordphrack2 6y ago
"There is no such "do wtf you want" license." I have to say there is a "do wtf you want" license. Hear me out. Say you like to speed and you have the money to pay fines and were okay with that. To a person like that what most people see as a "fine" becomes a "tax/fee." What am I getting at? Apples probably has a hand full of multi-layered legal strategies that ARMs legal team is somewhat aware of. Apple has the money to throw at it. Heck, they can start investing any estimated payout and if they do lose they will of still profited the interest from that investment plus the increased sales they think they are going to get.

monocasa 6y ago

Apple literally designed large parts of AArch64. There's no do wtf you want license that you can go out and buy, but Apple has one none the less from the sheer fact that it's partially their's to begin with and they negotiated it with ARM before AArch64 was even a twinkle in their eyes. ARM probably has some trademark mechanisms that they could in some world use to enforce compliance from Apple, but Apple has been super duper careful to refer to it as Apple Silicon rather than ARM.

skissane 6y ago

> There is no such "do wtf you want" license How do you know? ARM's license agreements with Apple are confidential and just about nobody knows what's actually in them (and the few who have seen them aren't allowed to talk about it.) The standard terms which ARM offers to its other customers may be quite different from the terms it has negotiated with Apple. Apple is a customer with unique clout and leverage, which means they can extract terms in negotiations which other customers may not be able to. If ARM offers Apple (or any other customer) "special terms", it wants to keep that fact confidential, so that other customers who have the (less generous) standard terms don't start pressuring for special terms for them as well.

marcan_42 6y ago
I know, because Apple went through the trouble of close-sourcing the M1 bring-up code in XNU source dumps... because it suddenly contains secret new instructions, while until now ARM XNU builds were largely public. These instructions enable an entire new set of parallel execution modes, among other things, to run more protected kernel code. Completely nonstandard stuff. Also, Apple somehow managed to push custom kernel support to the documentation of kmutil, but not the actual binary, until several macOS releases later. That would only happen if the latter got pulled for some extraneous reason. I've been working on this since December; the entire situation is all showing signs pointing straight at ARM's lawyers having gotten involved to some extent.
- monocasa 6y ago
  The kmutil stuff sounds way more like they cut it at the last second for some QA issue, but the documentation tech writers are a different team and that part was missed. They wouldn't have figured out issues with lawyers this quickly. The bring up stuff could be explained by being scared about some patent nonsense.
- skissane 6y ago
  I think there is another explanation for this than "they are breaking ARM's rules and either trying to hide it or getting in trouble" It is: "They are following ARM's special rules for Apple only but they aren't allowed to tell anyone that those special rules for Apple only exist" They might decide to leave certain processor extensions undocumented, even close source code which uses them, because they are worried disclosing them would implicitly reveal the existence of the "special rules for Apple", possibly violating the confidentiality clauses of the ARM-Apple contract containing those special rules. So I still don't see how you know that "There is no such 'do wtf you want' license", when the behaviour you describe is compatible with their being one, but its existence being secret
  - marcan_42 6y ago
    That's what I said: that they got a special exemption (which is not part of ARM's official license offering) to allow them to do this for embedded use cases (iOS devices), which implied that they wouldn't be documenting or having other people use these instructions. The problem is that the M1 threw a wrench in the works because now suddenly running non-Apple code that can use these instructions is allowed, and everyone else can see that they exist, so suddenly the existence of that special exemption is public.
    - skissane 6y ago
      > that they got a special exemption (which is not part of ARM's official license offering I agree except I'd say that it is part of ARM's official license offering, but only if your name is "Apple".

teclordphrack2 6y ago

"There is no such "do wtf you want" license." I have to say there is a "do wtf you want" license. Hear me out. Say you like to speed and you have the money to pay fines and were okay with that. To a person like that what most people see as a "fine" becomes a "tax/fee." What am I getting at? Apples probably has a hand full of multi-layered legal strategies that ARMs legal team is somewhat aware of. Apple has the money to throw at it. Heck, they can start investing any estimated payout and if they do lose they will of still profited the interest from that investment plus the increased sales they think they are going to get.