Xbox One OS build 8422

6.2.8422.0.fbl_fun_embedded_xos_devs.120920-1700
3.0.1223.0.fb_client_xdk_rtm.121004-0400
Build of Xbox OS
Screenshot
Release nameOctober 2012 XDK
OS familyWindows NT
Version number6.2
Build number8422
Build revision0
Architecturex64
Build labfbl_fun_embedded_xos_devs
Compiled on2012-09-20
Expiration date
Cert. expiry2013-07-22 (+305 days)
SKUs
XOS[a]
Preinstallation Environment
About dialog
Windows8-6.2.8422.0.fbl fun embedded xos devs-Winver.png

Xbox One OS build 8422 is a build of Xbox OS. It was originally shared in the form of an alpha development kit disk image dump of the October 2012 XDK on 2 August 2015 by warez group DemonSquad[1] following allegations surrounding the purchase of a development kit by an unknown individual on eBay in August 2012.[2] The operating system is based on a heavily stripped-down version of the Windows 8 codebase, leaving only the bare essentials required for launching Xbox One/Durango games such as minimal GDI+ and USER APIs.

It notably contains an early version of the Xbox XDK Launcher (referred to as the Xbox Compositor), which is merely a simple list of launchable/installed applications complete with a small number of configurable settings, along with additional debug information detailing the console's specifics and current network information printed at the top right.

The full recovery imaging tool for this build (which additionally includes a complimentary Preinstallation Environment image) was found on 7 February 2024.

Release notes[edit | edit source]

The below release notes (sourced from the January 2013 Xbox One/Durango XDK documentation) are republished here for archival purposes only.

Release notes

[This documentation is preliminary and is subject to change.]

Release Notes and Durango XDK Updates[edit | edit source]

The October 2012 release of the Durango XDK from Microsoft contains the following new features, tools, and documentation.

For features that shipped in a previous Durango XDK release, see the What's New document for that release. The most recent release notes and Durango XDK updates can always be found on Durango Downloads on Game Developer Network.

For access, log in with your ID and password on https://developer.xboxlive.com/en-us/platform; at the top of the page, point to Development and click Downloads.

The Durango developer support group sends e-mail to Durango developers whenever a new Durango XDK is released. Also, you can check with your account manager for the latest information about upcoming Durango XDK releases.

Durango XDK versions before July 2012 are retired[edit | edit source]

With the release of this XDK, versions of the Durango XDK before July 2012 are retired. We maintain download support for the three most recent releases of the XDK. You are encouraged, though, to update to each new release in order to get the most recent bug fixes and new features.

Changes for This Release[edit | edit source]

User-Mode Graphics Driver improvements[edit | edit source]

For this release, we have made a host of bug fixes and performance optimizations to the Durango User Mode driver. In particular, developers should note the following improvements:

  • Substantial performance and functionality improvements to the copying, updating, and resolving of subresources. As a specific example, in our own tests, copying a 1920x1080 32bpp resource from VRAM to VRAM went from >8 ms to 0.22 ms.
  • Improved performance in Map operations.
  • Fixes to Render Target Views (RTVs) and Depth Stencil Views (DSVs) created with TYPELESS formats when also bound as Shader Resource Views (SRVs) and Unordered Access Views (UAVs).
  • Target Independent Rasterization (which enables you to set the ForcedSampleCount member of D3D11_RASTERIZER_DESC1 and is a feature required for some D2D usage) is now implemented.
  • A new quality level (index 1) for 4X and 8X Multisample Anti-Aliasing (MSAA) has been added, providing new sample positions, different than the standard ones specified by D3D11.
  • DXGIDebug interfaces are now functional.

We expect that you will notice a substantial improvement in overall functionality and performance in your applications due to the driver fixes in this release.

As a result of underlying changes to the Durango OS, beginning with the November 2012 Durango XDK release the legacy graphics driver will no longer be supported. Microsoft will continue to invest significantly in improvements to the Durango User Mode driver through launch. Because we need your feedback and reproduction steps to find and eliminate remaining performance issues and bugs, we strongly encourage all developers to use the Durango User Mode Driver instead of the legacy driver. Tell us what's required to give Durango developers the right capabilities with the best possible performance.

New user interface improvements for PIX[edit | edit source]

For this release PIX now provides a way to analyze significantly more data at once, and a vastly improved way to view it. You can now open multiple frame captures simultaneously, enabling you to see events, resources, shaders and other PIX views for separate capture documents at the same time. This supports manual comparison of capture files for performance changes or to assist in debugging graphical issues.

In order to more easily manage all of these captures, you need more screen real-estate, so PIX now supports multiple monitors. You can drag and drop views from the main PIX interface to other monitors and flexibly arrange multiple collection of views to suit your needs.

You can also direct PIX to use a separate development kit for analysis than the one used for capture. This extends to multiple capture files; each open capture document can specify a different kit for analysis.

In addition, the events list now supports sorting and filtering. Events can be sorted ascending or descending by any counter column, and can be filtered by text string match or to GPU work events only. Together, this allows you to filter and sort by Draw calls with the longest measured duration, highlighting key rendering spikes in descending order.

Findings[edit | edit source]

The operating system is based on a heavily stripped-down version of Windows internally referred to as ClientCore,[3] and therefore only includes the necessary APIs required for games built for the Xbox One (then-codenamed Durango). Support for legacy Win32-based applications is almost entirely absent, with binaries commonly used by regular desktop applications being replaced with cut-down variants containing APIs found in regular PC games that additionally take advantage of DirectX or featureless stubs such as shell32.dll. Likewise, a unique disclosure warning with a similar premise to the NDA warning found in the watermarks of various Windows 8 builds can also be found within the aforementioned binary's respective MUI file, stating the following:

Use of all files being copied and installed during this installation process are subject to the terms and conditions of the Durango Development Kit License Agreement between Microsoft Corporation or its affiliate, and you or your employer. If you or your employer does not have a valid Durango Development Kit License Agreement, you are not authorized to use these files.

The build comes with a driver for an AMD Radeon HD 6300 engineering sample and contains several internal development tools for Xbox One applications, including tools used to update the firmware for the Xbox One's Kinect sensor (referred to internally as NUI 2.0 and AlphaSensor) and built-in utilities for the SmartGlass companion application. By default, the preinstalled image contains two applications used for testing the Kinect's hardware. On startup, multiple services that are required for full development kit functionality (such as an FTP server and a Telnet client) are launched alongside the compositor and the standard Windows command line interface, which can be switched to with the Alt+Tab hotkey.

The build is best utilized with an Xbox 360 controller, although it is possible to fake controller input by pressing the F12 key and using the keyboard to navigate through the interface.

A copy of the original recovery media is included within the available disk image in the form of a recovery.gdf file located at the disk root.

The full recovery imaging tool is a PE polyglot with a modified Xbox ISO image, where the volume descriptor is placed at the last sector (ignoring the PE signature placed after the ISO image) instead of sector 0x20, and the volume descriptor pointing to the root directory located after the recovery application PE at sector 0x37. Using a hex editor to place the volume descriptor at the expected location allows third-party tools like PowerISO to read the image.

Bugs[edit | edit source]

  • The Launcher found within the original leak's virtual hard disk (and the VHD provided within its recovery media) does not function by default due to file conflicts between the original WinPE recovery image (which was applied first) and the actual OS recovery image. A copy of the build's recovery VHD which contains a fixed Launcher was published in July 2021.

Gallery[edit | edit source]

Recovery Tool[edit | edit source]

Interface[edit | edit source]

Miscellaneous[edit | edit source]

Development kit[edit | edit source]

Kinect sensor[edit | edit source]

Notes[edit | edit source]

  1. Microsoft-Windows-XOSEdition~31bf3856ad364e35~amd64~~6.2.8422.0.mum in Windows\servicing\Packages; this build's registry hives incorrectly refer to itself as a Windows Preinstallation Environment image from a debug compile of Windows Vista Service Pack 1 build 6001.16437.

References[edit | edit source]

  1. "Xbox One Operating System, Have fun @KEEMSTARx @Microsoft @Xbox @gamespot", DemonSquad on Twitter. 2 August 2015.
  2. Purchese, Robert. "Microsoft Xbox Durango Development Kit" sells for thousands of pounds on eBay, Eurogamer. 13 August 2012.
  3. Microsoft-ClientCore-ApiSchema-Package~31bf3856ad364e35~amd64~~6.2.8422.0.mum in Windows\servicing\Packages; Microsoft-Windows-ClientCoreEdition~31bf3856ad364e35~amd64~~6.2.8400.0.mum in repair content packages for Windows 8 build 8400