. If the bootloader is shown as locked, initiate the "Unlock Bootloader" process. FFU and Loader Selection
Enthusiasts have bypassed this using "offline update" tools and registry hacks to install , which some users report runs "pretty nicely" for basic tasks. postmarketOS: Ongoing work exists to bring this Linux-based OS to the (codenamed "nokia-fame"). nokia lumia 520 custom rom work