Windows Phone 8 build 9543

Windows Phone 8 build 9543 is a build of Windows Phone 8. It was leaked on 2020-01-01 by gus33000. It is based on Windows 8 build 8124. It is the earliest leaked build of Windows Phone 8 and contains many differences compared to the next leaked Windows Phone 8 build 9571.

Particularities
This build boots from a FAT16 volume, which is unusual for a Windows NT build of the time. It includes many testing apps, some of which do not start or are in an unfinished state.

The Windows Phone app bar is not implemented like in the final builds of Windows Phone 8, instead it uses floating square buttons like the ones used in the Material Design concepts from Google from 2015. Many extra apps are pinned to the start screen, most likely for debugging purposes. One of them, tells the user the IP address of the device, to help with debugging over the network by using KDNET.

The settings app in this build, while present do not start. And this bug may have lasted for a while in previous builds of Windows Phone 8 due to a placeholder temporary WiFi app found in the app list, allowing the user to get to the WiFi page of the settings app without launching the settings app.

The camera app in this build simply states "Camera under construction".

Only the back button is functional in this build, and most of the side buttons remain unimplemented.

Applications take a long time to launch in this build, around 5 minutes is required for an application to launch, on a plain gray screen. Overall this build can be considered quite buggy, which is expected given this is an early build of Windows Phone 8.

This build also uses a special SKU variant of Windows called BootableSku. It has a few differences compared to the later MobileCore SKUs:

- The dism servicing stack is present in this compile, meaning drivers can be installed by using dism using infs. - Unlike later builds of MobileCore, this build uses WinSxS components.

The dism log files and the inf files also tell us this compile at one point included a battery driver for the RX-100 device it is running on. However someone removed this driver from the image using dism for unknown reasons.

WiFi is functional in this build, however as most applications do not start or are placeholders, it can only be used for debugging purposes.

It should be noted most of the tiles feature placeholder content. The notification count are faked and use two different styles: the traditional Windows Phone tile design and an earlier rounded badge at the top right corner of the tile. It is unclear if the later was considered for a final design choice or was simply a placeholder.