5 ms·

I would think porting OSX to ARM would be the real hurdle? Not undoable by any means, but the lion's share of the challenge.

wiml 13y ago
The machine-specific parts of OSX already run on ARM in the form of iOS. Also remember Apple has already successfully made two or three architecture transitions already: m68k to PPC to i386 to x86_64.
- justincormack 13y ago
  And the (brief) PPC64 transition.
mcculley 13y ago
I wouldn't imagine porting OS X to ARM would be the hurdle as most of it is already done in that iOS is most of OS X. Apple has full control of that source code base and probably already has done this, like they did during the transition to IA-32. It would be the third party applications that would be a hurdle. Without a transparent layer like the deprecated Rosetta, they would not be able to run existing applications and would have to explain that a new MacBook Air can't run all of the old MacBook Air applications. Maybe if they come out with an ARM powered laptop, they will call it something other than MacBook Air to avoid that confusion.
- gonzo 13y ago
  Just the Apple Air, I'd bet. Don't forget that Apple has spent years getting everyone on Xcode, and disciplining them to avoid the parts that would make a recompile & test straight-forward. They also have a "good enough" office suite (for many people), as well as the iWork apps. Such a device could potentially also run iPad apps without much change.
mikeash 13y ago
The real challenge will be figuring out the compatibility question for third-party software. Do you make everybody recompile before their stuff works on the new hardware? Do you ship an emulator for x86-64 for a while, like they did when they went PPC->Intel? OS X and its predecessors have already been ported to run on a bunch of architectures: x86-64, i386, PPC64, PPC32, PA-RISC, SPARC, and Motorola 68k. All, or nearly all, of the CPU-dependent parts of the OS are the parts that are shared between OS X and iOS. Making OS X run on ARM would be trivial for Apple, and I'd be shocked if they didn't have it up and running already as a hedge.
- endianswap 13y ago
  That was my thought, too. It seems like if they do this then they'll be going down the same path as Microsoft did with the Surface RT and Surface Pro, right?
  - twoodfin 13y ago
    Not exactly. Remember that the Surface RT deliberately restricted the applications that could be run via Win32 on the familiar desktop. Just about every third party application needed to adopt the new RT APIs and run "Metro"-style. If they go down this road, Apple will not put constraints like that on their Mac developers: I'd expect that all the most commonly used frameworks would continue to be available, and porting most applications would amount to a recompile against a new Xcode.
    - rmrfrmrf 13y ago
      I never once gave much thought to the idea that Apple would somehow shut out unsigned apps from its desktop computers, for the main reason that there would be too many existing apps that would suddenly lose functionality and cause a backlash. With a port to ARM, though, Apple can simply say that the developers haven't ported their app to the new architecture yet, and that more apps will become available as developers catch up. Meanwhile, all those apps that currently require some kind of lower-level access could be banned. On the other hand, I think that would be a huge boon for non-power users; it would be nearly impossible for malware to get onto the computer, and even annoyances like Adobe's and Microsoft's auto-updaters would finally get funneled though the App Store, which would prevent programs like that from constantly occupying memory/CPU/network. For this to work, though, I think Apple would be wise to include some kind of developer mode feature (perhaps even forking over the $99/year fee) that would allow unsigned or potentially dangerous apps to run. All of this (admittedly wild; sorry, coffee is kicking in) speculation definitely has me excited for the future of Apple, though! I haven't felt like that since Steve was around.
rsynnott 13y ago
Given Apple's history with this stuff, there's a very good chance that that's already done. Intel was supported internally for years before the PPC -> Intel change.
- cpeterso 13y ago
  Jobs claimed that Apple maintained a secret x86 port of OS X for five years before the public release. A small cost.
  - leoc 13y ago
    Apparently this is true enough, with the added qualification that for the first year or so it was largely secret from Apple too. :) http://www.theregister.co.uk/2012/06/11/apple_project_marklar_secrets/ http://www.theregister.co.uk/2012/06/11/apple_project_markla... http://www.quora.com/Apple-company/How-does-Apple-keep-secrets-so-well/answer/Kim-Scheinberg http://www.quora.com/Apple-company/How-does-Apple-keep-secre... (Though of course the fact that the OS X codebase had been kept cleanly portable was neither one person's secret project nor a matter of chance.)
  - rsynnott 13y ago
    Makes perfect sense, really; not only would it be a hedge against having to adopt Intel, but just the value of having it around to show IBM people when negotiating over the PPC would probably have been worth the cost.
gozzoo 13y ago
I don't think they will go that path. It would make much more sense to introduce a desktop version of iOS itself. iOS has already everything that's needed for a light desktop OS. It would provide much better experience than ChromeOS, there are already thousands of applications doing about anything and it would require very little effort to adapt iOS to run as a desktop OS and to adapt the existing applications. I think that a hint for that is the recent port of Microsoft Office. If users want more sophisticated OS they can just use 13" MacBook Pro. It's quite easy to guess that the next version will be thinner and lighter and probably cheaper - very similar to the current MacBook Air.
coldtea 13y ago
They've already ported it. iOS is OSX for ARM plus different UI stuff -- all the kernel, basic userland etc are there. So, it's mainly a matter of porting the higher level stuff -- mainly the Cocoa libs, which are slightly different on iOS vs desktop OS X.
- sliverstorm 13y ago
  I guess I'm not familiar with just how much iOS and OSX shares.
userbinator 13y ago
> but the lion's share of the challenge. This would've been the perfect phrase last year.

wiml 13y ago

The machine-specific parts of OSX already run on ARM in the form of iOS. Also remember Apple has already successfully made two or three architecture transitions already: m68k to PPC to i386 to x86_64.

justincormack 13y ago
And the (brief) PPC64 transition.

mcculley 13y ago

I wouldn't imagine porting OS X to ARM would be the hurdle as most of it is already done in that iOS is most of OS X. Apple has full control of that source code base and probably already has done this, like they did during the transition to IA-32. It would be the third party applications that would be a hurdle. Without a transparent layer like the deprecated Rosetta, they would not be able to run existing applications and would have to explain that a new MacBook Air can't run all of the old MacBook Air applications. Maybe if they come out with an ARM powered laptop, they will call it something other than MacBook Air to avoid that confusion.

gonzo 13y ago
Just the Apple Air, I'd bet. Don't forget that Apple has spent years getting everyone on Xcode, and disciplining them to avoid the parts that would make a recompile & test straight-forward. They also have a "good enough" office suite (for many people), as well as the iWork apps. Such a device could potentially also run iPad apps without much change.

mikeash 13y ago

The real challenge will be figuring out the compatibility question for third-party software. Do you make everybody recompile before their stuff works on the new hardware? Do you ship an emulator for x86-64 for a while, like they did when they went PPC->Intel? OS X and its predecessors have already been ported to run on a bunch of architectures: x86-64, i386, PPC64, PPC32, PA-RISC, SPARC, and Motorola 68k. All, or nearly all, of the CPU-dependent parts of the OS are the parts that are shared between OS X and iOS. Making OS X run on ARM would be trivial for Apple, and I'd be shocked if they didn't have it up and running already as a hedge.

endianswap 13y ago
That was my thought, too. It seems like if they do this then they'll be going down the same path as Microsoft did with the Surface RT and Surface Pro, right?
- twoodfin 13y ago
  Not exactly. Remember that the Surface RT deliberately restricted the applications that could be run via Win32 on the familiar desktop. Just about every third party application needed to adopt the new RT APIs and run "Metro"-style. If they go down this road, Apple will not put constraints like that on their Mac developers: I'd expect that all the most commonly used frameworks would continue to be available, and porting most applications would amount to a recompile against a new Xcode.
  - rmrfrmrf 13y ago
    I never once gave much thought to the idea that Apple would somehow shut out unsigned apps from its desktop computers, for the main reason that there would be too many existing apps that would suddenly lose functionality and cause a backlash. With a port to ARM, though, Apple can simply say that the developers haven't ported their app to the new architecture yet, and that more apps will become available as developers catch up. Meanwhile, all those apps that currently require some kind of lower-level access could be banned. On the other hand, I think that would be a huge boon for non-power users; it would be nearly impossible for malware to get onto the computer, and even annoyances like Adobe's and Microsoft's auto-updaters would finally get funneled though the App Store, which would prevent programs like that from constantly occupying memory/CPU/network. For this to work, though, I think Apple would be wise to include some kind of developer mode feature (perhaps even forking over the $99/year fee) that would allow unsigned or potentially dangerous apps to run. All of this (admittedly wild; sorry, coffee is kicking in) speculation definitely has me excited for the future of Apple, though! I haven't felt like that since Steve was around.

rsynnott 13y ago

Given Apple's history with this stuff, there's a very good chance that that's already done. Intel was supported internally for years before the PPC -> Intel change.

cpeterso 13y ago
Jobs claimed that Apple maintained a secret x86 port of OS X for five years before the public release. A small cost.
- leoc 13y ago
  Apparently this is true enough, with the added qualification that for the first year or so it was largely secret from Apple too. :) http://www.theregister.co.uk/2012/06/11/apple_project_marklar_secrets/ http://www.theregister.co.uk/2012/06/11/apple_project_markla... http://www.quora.com/Apple-company/How-does-Apple-keep-secrets-so-well/answer/Kim-Scheinberg http://www.quora.com/Apple-company/How-does-Apple-keep-secre... (Though of course the fact that the OS X codebase had been kept cleanly portable was neither one person's secret project nor a matter of chance.)
- rsynnott 13y ago
  Makes perfect sense, really; not only would it be a hedge against having to adopt Intel, but just the value of having it around to show IBM people when negotiating over the PPC would probably have been worth the cost.

gozzoo 13y ago

I don't think they will go that path. It would make much more sense to introduce a desktop version of iOS itself. iOS has already everything that's needed for a light desktop OS. It would provide much better experience than ChromeOS, there are already thousands of applications doing about anything and it would require very little effort to adapt iOS to run as a desktop OS and to adapt the existing applications. I think that a hint for that is the recent port of Microsoft Office. If users want more sophisticated OS they can just use 13" MacBook Pro. It's quite easy to guess that the next version will be thinner and lighter and probably cheaper - very similar to the current MacBook Air.

coldtea 13y ago

They've already ported it. iOS is OSX for ARM plus different UI stuff -- all the kernel, basic userland etc are there. So, it's mainly a matter of porting the higher level stuff -- mainly the Cocoa libs, which are slightly different on iOS vs desktop OS X.

sliverstorm 13y ago
I guess I'm not familiar with just how much iOS and OSX shares.

userbinator 13y ago

> but the lion's share of the challenge. This would've been the perfect phrase last year.