For hacker Ben | imbushuo to be able to install Windows 10 for ARM on a Microsoft Lumia 950 XL , he had to develop a custom Unified Extensible Firmware Interface (UEFI) bootloader for the phone. After all, Windows 10 requires a secure boot environment. The hacker did the work on the custom UEFI last month, and today he tweeted images of a Lumia 950 XL running the ARM version of the operating system.In case you've forgotten, the Lumia 950 XL was launched in November 2015, and is powered by a Snapdragon 810 chipset containing four Cortex-A57 and four Cortex-A53 cores. The phone was released with Windows 10 Mobile out of the box.While impressive, the Lumia 950 XL has a long way to go before it can match the HTC HD2 , which originally was powered by Windows Mobile Professional 6.5. Released in 2009, the HTC HD2 has been loaded with various versions of Android including Nougat source: @imbushuo via MSPoweruser