Windows Core build 16236

Build of Windows Core
OS familyWindows NT
Version number10.0
Build number16236
Build revision1003
Build labrs_onecore_webplat_stage_dev3
Compiled on2017-07-07
Expiration date
Cert. expiry2018-02-22 (+230 days)
Product type

Windows Core build 16236 is an internal build of Windows Core, which was found on 30 April 2023, and was publicly uploaded onto a GitHub repository on 29 August 2023.[1]

It is notably the earliest available bring-up build of the internal Windows Core OS effort, designed to test the operating system's base layers and its surrounding components. The build belongs to an internal development branch intended for the Microsoft Edge web platform and additionally utilizes a test code signing certificate signed by the Microsoft Test PCA 2010 certificate chain. The provided operating system image was originally dumped from a Microsoft Lumia 950 (RM-1105) prototype.[a]

By default, the operating system includes a test shell known as the Reference Composer, which includes a basic windowing management system and a separate toggleable sample experience application that makes use of basic Universal Windows Platform controls. The composer includes a button to launch the default Windows 10 IoT Core shell application (referred to as Chucky, in reference to the Child's Play character of the same name)[b] as well as the ability to cycle through background images present across available storage mediums.

If the Reference Composer fails to launch properly, crashes during operation or is otherwise not present, a fallback diagnostic composer which prints the IP address of the currently-running device on top of a black screen (allowing Microsoft employees to debug over a local network) is automatically invoked by the CoreShellHost application, a component primarily responsible for the initialization of the built-in OS shell.

How to install[edit | edit source]

QEMU installation guide:

Prerequisites[edit | edit source]

The following requirements used in order to install this build onto a virtual machine are listed below:

  • A copy of QEMU v6.2.0, modified for Windows ARM32 compatibility
  • A version of the TianoCore EDK II firmware designed for ARM32 emulation (included above), to be placed in the QEMU installation directory under fw/QEMU_EFI_1512_driver1998.fd
  • One virtual hard disk image (for storing the operating system)

Instructions[edit | edit source]

Diskpart and then type:

create vdisk file="C:\CoreOS16236\HDD.vhd" maximum=65536 type=expandable
select vdisk file="C:\CoreOS16236\HDD.vhd"
attach vdisk
convert gpt
create partition efi size=100
format quick fs=fat32
assign letter=F
create partition primary size=1400
format quick fs=ntfs
assign letter=G

Use DISM to apply the MainOS wim:

dism /Apply-Image /ImageFile:C:\Inkman\MainOS.wim /Index:1 /ApplyDir:G:\

Switch back to diskpart and type:

create partition primary size=277
format quick fs=ntfs
assign mount=G:\OSData
create partition primary
format quick fs=ntfs
assign mount=G:\Data

Use DISM to apply the Data wim:

dism /Apply-Image /ImageFile:C:\Inkman\Data.wim /Index:1 /ApplyDir:G:\Data

Unzip to G:\OSData.

Copy EFIESP partition content from other ARM32 Windows Phone build and execute:

bcdboot G:\WINDOWS /s F:\

Unzip to F:\.

Paste and run the contents of the below script onto a batch file within the QEMU installation directory.

set MAIN="C:\CoreOS16236\HDD.vhd"

qemu-system-arm ^
    -M virt,highmem=false -cpu cortex-a15 -smp cores=4,threads=2 -m 4096 ^
    -device usb-kbd,id=kbd -device usb-tablet,id=mice ^
    -drive id=SD,if=none,file=%MAIN% -device sd-card,drive=SD ^
    -bios fw\QEMU_EFI_1512_driver1998.fd -device VGA ^
    -rtc base=2017-07-07,clock=vm ^
    --accel tcg,thread=multi

You may need to restart the virtual system multiple times to get the reference composer loaded properly.

Gallery[edit | edit source]

Notes[edit | edit source]

  1. TALKMAN_LTE_AMERICAS; Microsoft equipment part number E1755063
  2. The application itself is not present by default and must be manually installed using components from a nearby Windows build.

References[edit | edit source]