You can boot a minimal Linux kernel and access a terminal interface or basic lightweight desktop environments.

For true open-source enthusiasts, postmarketOS (a touch-optimized Linux distribution based on Alpine Linux) has seen experimental builds for the Lumia 520.

The installation process involves:

The industry-standard tool for this is WPInternals . This tool allows you to unlock the bootloader of Windows Phones.

If installing Android, a custom partitions tool maps out space for a custom recovery (like TWRP), which replaces the stock Windows recovery screen.

The first step is unlocking the phone's bootloader. The simplest method is to use WPinternals:

: Manipulating bootloaders is inherently risky; using the wrong FFU image or flash loader can "hard brick" the device, making it unusable. Hardware Longevity

Retains the native Live Tile aesthetic and ensures all hardware features (camera, buttons, calling) work perfectly.

Since the 520 wasn't officially supported for Windows 10, you must use "Interop Tools" to spoof the device ID.

This comprehensive guide covers everything you need to know about Nokia Lumia 520 custom ROMs, including prerequisites, available operating systems, and a step-by-step installation walkthrough. Why Install a Custom ROM on a Lumia 520?

The essential open-source utility created by developer Rene Ladan that unlocks the bootloader, enables Root Access, and mass-storage mode on Lumia phones.