Microsoft's Windows Phone 8 finally gets a 'real' Windows core

Microsoft's Windows Phone 8 finally gets a 'real' Windows core

Summary: The rumors were true: Windows Embedded is out and the Windows NT kernel is in with Microsoft's Windows Phone 8.


Microsoft execs have always been reticent to talk about the guts of its Windows Phone (and its predecessor, Windows Mobile) operating systems. Until today, June 20, that is.

Up until this point, the core of the Windows Phone operating system was Windows Embedded Compact, one of the several embedded operating system SKUs from Microsoft -- with a layer of customized Windows Phone technology on top. But with Apollo, the next release of the Windows Phone OS, Microsoft is switching to the Windows NT "core." This is a move that's been rumored for months, and the culmination of a corporate goal dating back almost a decade.

What does Windows NT core mean, exactly? It is the "kernel." But it goes beyond that.

As of Apollo, the Windows Phone OS will include the same file system (NTFS), same networking stack, same security elements, graphics engine (DirectX), device driver framework and hardware abstraction layer (HAL) as "big" Windows. Apollo also will include the mobile variant of the same browser -- Internet Explorer 10 -- as Windows 8.

As I've blogged before, Microsoft makes the operating-system sausage differently these days. Microsoft teams building any kind of Windows operating system can pick and choose the pieces of Windows they need for different platforms. Some teams use more of the pieces; some use less. This approach is an outgrowth of Microsoft's MinWin project, which was an effort starting around the time of Windows Vista untangle the Windows mess and make it available as a bunch of smaller pieces that could be recomposed for different environments.

A true Windows core in Windows Phone is what is going to bring multicore support to the platform, according to Senior Product Manager Greg Sullivan. Sullivan said the use of the Windows Embedded 6.x core is what prevented this. With the new core, "theoretically you could have up to 64 cores supported," he said, "thought it could be a long time until we ever support that," if ever.

A common core across Windows Phone and Windows 8 also should be good news for developers. It would seem now you could write once and really have it run anywhere? But the reality is a bit more complicated.

Developers cannot take their Windows app binaries and just run them on Windows Phone 8. However, there is a high degree of code reuse possible, Sullivan said.

Microsoft execs have said repeatedly that existing Windows Phone 7 apps will run on Windows Phone 8. The two phone platforms are binary compatible, Sullivan reiterated.

According to Microsoft officials, the developer platform for Windows Phone 8, which are powered by ARM processors, and Windows RT -- the version of Windows that runs on ARM processors -- is "similar." But it's not exactly the same.

"We don't have the unified runtimes and APIs (application programming interfaces) exposed," Sullivan acknowledged. "But the tools are the same."

The new developer environment for Windows Phone 8 does share commonalities with what Microsoft has announced for Windows 8 and Windows RT. Microsoft is announcing today that Windows Phone 8 has full C and C++ support, just like Windows 8 and Windows RT do. Microsoft officials have said the XNA tools/runtime environment used primarily by game developers isn't supported on Windows 8. On Windows Phone 8, XNA is "supported," so existing Windows Phone games will run. But Microsoft's advice to phone developers going forward, just like it is for Windows 8, is to use native code, meaning C and C++, to write games. (Windows Phone 8 can and will support popular game engines such as Havok, as well as native DirectX-based game development, the Softies are saying.)

Though today's Windows Phone Summit -- where this information was disclosed officially -- originally was billed as a developer event, it morphed into more of a high-level overview event. Microsoft officials say they will have more detailed developer information and code to share with Windows Phone programmers at a later date, but won't say when this is.

Update: We know Windows Phone 7.x apps can run on Windows Phone 8, according to Microsoft. But what about the reverse? Can Windows Phone 8 apps run on existing devices? Short answer is no.

Longer answer, courtesy of a Microsoft spokesperson:

"We are designing Windows Phone 8 with the goal of allowing all existing applications in the Windows Phone Marketplace to work on Windows Phone 8 devices. We will also be working closely with key developer partners to create versions of applications that take advantage of some of the new features available in Windows Phone 8.

"New applications compiled specifically for Windows Phone 8 will not be made available for Windows Phone 7.x devices."

Topics: Windows, Microsoft, Mobility, Operating Systems, Software, SMBs


Mary Jo has covered the tech industry for 30 years for a variety of publications and Web sites, and is a frequent guest on radio, TV and podcasts, speaking about all things Microsoft-related. She is the author of Microsoft 2.0: How Microsoft plans to stay relevant in the post-Gates era (John Wiley & Sons, 2008).

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  • will WP7 users be able to upgrade?

    Well? Will we?
    diane wilson
    • Unfortunately...

      No. WP8 will not run on existing WP7 devices. :(
      • Yeah

        Sure am Glad I ignored those people pushing the Lumia 900!
    • Windows phone 7.5 phones will get upgrades

      Windows phone 8 adds support for multi-core processors, C/C++ support, SD cards(probably mini) with full file support. Because current Windows Phone 7.5 phones do not include these features it won't be practical or may even be problematic to include in upgrades to Windows phone 7.5. But many of the new features in Windows phone 8 will be available to Windows phone 7.5 as a 7.8 upgrade. While you won't get a Windows phone 8 upgrade there will be upgrades that provide improvements that a 7.5 phone can use.
      • List 7.8 please

        Can you list all the features the old phones will get? Thanks
      • 7.5 Won't Run Win phone 8 apps

        Sounds a lot like what I have been thinking
  • We just get an upgrade to 7.8

    Yep, no full upgrade, but we do get a features upgrade with 7.8.

    My phone will be 2 years old in February 2013. I'll be ripe for a WP8 upgrade!!!

      I HATE the oversize icons on Windows phones and the future Windows is UGLY and primitive!
      • Better than what??

        a pencil and paper, android is a joke of an OS
      • Windows 8 Phone


        I have a Windows 7 phone and think it is a great product. Why are you wasting your time in this forum making comments about a the boxes on a phone?
  • Will existing WP users get Apollo?

    The answer is officially no.

    Read more:

    Mary Jo Foley
    • Oh boy

      WM6 not compatible with WP7 not compatible with WP8 not compatible with WinRT not compatible with Win8. Fabulous MS.
      • Importantly they kept the windows branding;-)

        Its quite bizarre that significant changes are still being made to a platform only a few months from RTM.

        "Microsoft officials say they will have more detailed developer information and code to share with Windows Phone programmers at a later date, but won't say when this is."

        They're saying this a lot lately. I suspect it isn't they're not saying, but they don't know!
        Richard Flude
      • Shouldn't it slowly be called Doors.... nowhere...but maybe as Richard says branding matters:) just wondering how long can MS folks keep up with their own mess...maybe for as long as they can sell it....
      • And the alternatives are just soo much better?

        @Spalda... how far does Apple update the iOS on your iPhone etc? How many Androind upgrades do most users get.... one, maybe two if the OEM is generous. Iceream launched months ago, and many who started with 2.2 won't ever be able to "officially" recieve it and many with 2.3 are only NOW just seeing the new OS version being pushed to their model of phone!

        MS is not handling this any different from the other major players so don't be fascetious!
      • Yes they are

        @kaninelupus take off your fanboy glasses. Apple announced that the iPhone 3Gs will get iOS 6. Microsoft will not support phones from 2012 and Apple is supporting (even if in a limited fashion) a phone introduced on June 8, 2009. You know when Microsoft was pushing Windows Mobile 6.3. It originally came with iPhone OS 3.0. So in short the competition is much better, and WP stinks. WP 7 was a stop gap OS meant to freeze the marke till they could make a new OS. Even though Microsoft is claiming they're trying ti Unify the OSs, they're still fragmented as ever. There are no less than 7 versions of the OS.
        There's home, and Pro, in 32, and 64 bit, there's Surface, there's Phone, and the business SKUs wach looks similar but will all have different requirements, and will run different versions of the same software. That spells [b]Fragmentation[/b]!
        Jumpin Jack Flash
      • @JJF

        OK so WP7 users get WP7.8 I guess MS could have played the Apple game and said you too get WP8 but it just wont have x,y,z and anything else that is hardware specific. No They were honest and said we will give you everyting except what is hardware specific and name it 7.8.

        No difference in the type of update existing users will get. Just not the BS of saying you get WP8 but crippled.

        Get off your high horse please and lets have an honest debate not some fanboy spewing drivel.
      • what is happening?

        clearly microsoft is created a mess, they are not sticking to anything firmly, windows 8 has not yet reached the mass and now comes another os which is incompatible with mango os devices, clearly this kind of actions will raises doubt among the consumer whether to go ahead with windows devices? windows 7.8, windows RT, windows 8, windows phone 8.... microsoft seriously what your are up to?
  • I knew it! XNA could have been supported on Windows 8!

    I am a developer who has written a numbre of XNA games and apps for WP7. I was devastated to hear that XNA wouldn't work for WinRT metro apps. People said it was because the new WinRT engine just didn't support XNA. The fact that WP8 will support XNA just proves that is not the case.

    I think the real issue here is that there is a perception amongst old-school game devs that the CLI and C# just are performant enough for "real" games. The advent of HTML5 games (MUCH slower than C#) proves this wrong. Casual games don't have to squeeze out every single bit of performance like massive 3D games do. My XNA games run beautifully on the lowest-end WP7 hardware without a hiccup. They will run just as well on WP8 and would have run fine on WinRT if MS had allowed it.
    • MonoGame or SharpDX

      If you just want C# with access to DirectX APIs... try SharpDX. It gives you a super thin and fast C# binding for DirectX which works on Windows 8 Metro and now Windows Phone 8 as well.

      If you want an API that is like XNA then look at MonoGame. It is an open source implementation of XNA for non-Microsoft devices (iOS, Linux, Android, etc) which has recently added Windows 8 Metro support (and now Windows Phone 8). There are several WP7 developers using MonoGame to get to Windows 8 and Windows Phone 8.