Windows Phone OS 7.0 Architecture Guide

A Dutch web site has gotten their hands on some interesting Microsoft documentation for Windows Phone 7. It’s in Dutch (go figure), but thanks to Google Translate, the following facts emerge (some previously known):

Like many operating systems, Windows Phone OS 7.0 utilizes a layered architecture, with a kernel space and a user space. The kernel, file system, and graphics rendering occurs in kernel space, as does Phone Update, which is apparently the name for the Windows Phone version of Windows Update (!).

The Windows Phone OS 7.0 kernel is based on Windows Embedded CE 6.0 and supports up to 32,000 simultaneous processes, each with access to 1 GB of virtual memory. The OS is 32-bit and thus can access up to 4 GB of RAM.

Windows Phone OS 7.0 supports two file systems, IMGFS (which I’ve never heard of) and exFAT (the version of FAT that can handle files bigger than 4 GB).

Windows Phone OS 7.0 utilizes Direct3D 11.

Summary of minimum hardware requirements: ARMv7-based microprocessor, DirectX with hardware acceleration, capacitive multi-touch screen, digital camera, Bluetooth and Wi-Fi, FM radio receiver, A-GPS, accelerometer, compass, and light and proximity sensors. Phones must have also have Back, Home and Search buttons, two volume buttons, a power button and camera button.

A Windows Live ID is required to synchronize data between the phone and online services, and to access Windows Marketplace.

There will be a Windows Genuine Phone certificate that ensures that phones are genuine. (Ah, DRM.)

Software updates will be delivered to Windows Phone users via Microsoft Update, as they are for desktop Windows users, and the software component, called Phone Update, exists both on the phone (for smaller updates) and in the Zune PC software (for larger updates). Users will be notified to tether their phones to a PC if such an update is required.

Wireless carriers can change the default search engine in the browser. (But based on what I was told, the hardware Search button will always utilize Bing, regardless.) They can also change the Windows Phone boot screen, wallpapers, ringtones, various icons (3G and Wi-Fi) and can add Live Tiles to the home screen. The standard Microsoft tiles cannot be changed or removed. They can also add their own applications, though these must first be approved by Microsoft. (I’m guessing this is a quality concern.) But they must be free apps, not paid, and only six can be added to any phone, using up to 60 MB of space.

Thanks to Rolf Siebelink for the tip!

This entry was posted in Developer, Windows Phone. Bookmark the permalink.

24 Responses to Windows Phone OS 7.0 Architecture Guide

  1. jctierney says:

    Wow, Windows Genuine Phone, that just seems crazy. Then again, most people would buy these devices brand new, so I guess this shouldn’t be too big of a deal for the average person.

    Everything else seems interesting, at least it doesn’t seem like Microsoft will allow phone developers to put a “skin” over the top of Windows Phone, like they did so often with Windows Mobile 6.1 and 6.5. That’s good.

  2. interframe says:

    Interesting moves Microsoft is making. All of this ensures that fragmentation won’t destroy this new platform, like it did with Windows Mobile and is now starting to happen with Android.

    Windows Mobile was an ugly mess. Ugly random apps, too much random hardware, and no control. Android’s situation will be even worse 5-10 years down the road. Open Source is like anarchy, theres no order or law, and while there are some benefits, things can get really ugly.

  3. claytontlewis says:

    This sounds to me like there will be no home-cooked ROMs.



  4. davelindhout says:

    Can you say ‘walled garden’?

    Many of the complaints of the iPhone appear to be standard issue in WP7. Personally, I don’t think this is a bad thing, but all of the walled garden guys have got to be looking at Android.

    • Paul Thurrott says:

      What do you mean?

      • claytontlewis says:

        Its not that big of a deal to me that it won’t be really hackable, but still somewhat disappointing. The guys over at XDA do some awesome stuff and even I don’t take full advantage of it, it still feels awesomely geeky to run a custom ROM.

    • interframe says:

      Sure, its a little strict but i dont think Microsoft has the intention to make it as locked down as the iPhone.

      Many of the problems that were caused in Windows Mobile (one of the most hated mobile OS’ of this modern smartphone era) was simply because that entire platform lacked rules and boundaries.

      What you got was most OEMs coming out with ridiculously under-powered and down right horrible devices. And you also got apps that were either written 10 years ago or modern apps that were just written horribly and worked horribly. The standard UI for Windows Mobile apps was terrible and not a lot of developers came up with something better.

      People: there is a dark side to all of this openness and all you have to do is look at Windows Mobile to see it.

      With Windows Mobile, it wasn’t even Microsoft’s OS; it was a bunch of companies taking it and turning it into their version of something that was only slightly better but still mediocre (with the exception of maybe HTC’s Sense).

      The limitation MS is putting in WP7 is to make sure they won’t repeat that mistake which was the core reason of why so many people hated Windows Mobile: fragmentation.

      • gpsarakis says:

        I also expect MS will open it up quicker over time. I think come this time next year and WP7 has been out for a bit it will probably already be more open, or at the least have some or all of the features some of the die-hard tech-geeks want, C&P etc.

    • gpsarakis says:

      The “walled-garden” moaners are the minority. If the iPhone has proven anything it’s that the general phone buying public want something that looks good and does the things they expect, not how hackible it is.

      That genuin cert could be in place to protect the marketplace apps from being pirated for example, and not so much stopping custom ROMs. As with certs on Windows, the one in WP7 should be transferible. Paul maybe you can get more info on this?

      There has to be a way, in the future, to move from your current phone to a newer windows phone that you buy 1 or 2 years later. If the cert works like I think, then it ties your liveID (thus marketplace buys) to a phoneID, so someone can’t just take your LiveID and rack up charges to you i’m guessing? All that has to be able to be moved to a new phone.

  5. vangrieg says:

    Well, there’s one potentially disastrous bit in this information (not listed here) – OEMs will supply graphics drivers. This means potential crappy performance (hello HTC) and delays in updates for some devices (as OS updates will depend on whether OEMs have prepared the drivers on time, which they won’t). So this spells fragmentation all over WP7. If the news is true, of course.

    One glimpse of hope is that the leaked documentation is dated February 2010, which is before MIX, so it can be outdated.

    • Paul Thurrott says:

      But the graphics hardware and drivers must meet certain requirements. I don’t believe this will be an issue, honestly.

      • vangrieg says:

        Well if there will be a strict approval process then we’ll just never see updates from OEMs. HTC and the like just can’t make decent drivers, never could, and never will.

      • Paul Thurrott says:

        I think the hardware is going to be fairly standardized, so I can’t imagine this is going to be an issue. Microsoft is very concerned that people have a “Windows Phone experience” not an “HTC whatever experience” or a “Bob’s smart phone experience.” This means consistency across the board, and something low-level like graphics certainly falls into that category. I think this is a “nothing to see here” non-issue.

      • roteague says:

        I think you are right, this stuff is a non-issue. Unlike a lot of other here, I won’t say that Windows Mobile was bad, it was good for what it was …. a stylus based OS. Fast forward into a new generation, and see that no longer works.

        I’ve been doing Windows Mobile development since the first CE device was introduced (in C++ no less) and up until a little over a year ago, I did my last Windows Mobile project for a client.I’ve enjoyed it, but I haven’t been as excited about mobile development in years, as I am towards the Windows Phone 7 devices. I think that support for this device will just explode.

    • gpsarakis says:

      Since the graphics are specific and strict I’m sure MS will have a reference driver of their own which should give good performance as a starting point. And since OEM updates have to go through MS, they’ll make sure the drivers are good this time, none of that HTC madness.

  6. crball says:

    Paul, one thing about WP7 that I have not seen assurance on yet is FULL exchange syncing and support. Please tell me they didn’t do like crApple and exclude tasks and notes!

    Also, I don’t think it will be locked down in an insane manner like the iPhone because there isn’t a loon at the helm demanding maniacal control. I think they are just trying to keep it rational and a great experience. I could care less about a cooked ROM if out the door it looks and performs beautifully.

    • Paul Thurrott says:

      I would imagine it will be at least identical to how it works in Windows Mobile today. They have specified that multiple Exchange accounts will be supported.

  7. crball says:

    That is great news on both counts. Jeez! Can’t they release the phones faster? I need one of those now! LOL!

  8. mmitch2k says:

    I currently have an iphone, prior to that I was always a windows mobile dude, even had an iPaq, my last phone prior to my iphone was the Tilt. When my contract expired I was torn bedtween goign for the tilt2 and the iphone. I chose the iphone because I felt like windows mobile was dead, the mainstream press didnt even know it existed, developers ignored it, and it just became current joke to the tech press. I always felt I was missing out on something. After having an iphone I can truly say its the most convenient piece of tech I have ever purchased. Although I generally cant stand apple products, they really got this right. When I saw win Phone 7 for the first time I FINALLY now have a reason to switch back. It all looks and sounds great. My only concern is the frequency of updates. I am afraid that WP7 will always be a couple generations behind the iphone/android, especially if MS sticks to their current 2x a year update cycle they do with bing/Xbox. I am hoping after I get a new WP7 device this holiday that I dont get that feeling that i’m still missing out on something :)

    • roteague says:

      ” developers ignored it”

      Huh?? You weren’t looking in the right place then. I’ve had an iPaq for years, and currently have a Socket sitting around the house, and never had any problem with apps … then again, I wrote most of my own.

  9. ropp29 says:

    The Windows Genuine Phone DRM thing is going to really annoy everyone at PPCGeeks and XDA. The ability to have custom ROMs is one of the things that has kept Windows Mobile afloat. Microsoft is really alienating current Windows Mobile users that appreciate the openness of Windows Mobile.

    • Richard Hamilton says:

      I kinda agree. My Omnia shipped with 6.1, and I’m grateful for 6.5 ROM’s to be made available. This new physical device drm is kinda a dick move. The hobbyists make up a significant part of the existing WinMo base, and alienating them even more kinda isn’t the best idea. These people are the same people who recommend a phone platform to non techie friends and family. Just something to think about.

  10. crball says:

    @ropp – well you forget about annoying the regular users of Windows Mobile who had to suffer with the system as is which I think is more important. The “openness” didn’t help the travesty of what it had become.

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s