Unlike Samsung (Odin) or Xiaomi (Mi Flash Tool), Nokia devices use a proprietary tool called . You cannot use standard fastboot flash commands easily because Nokia locks the bootloader tightly.
One legendary post from XDA user (account since deleted) detailed how a “Nokia 42 ROM Lite” was used to revive a Nokia N900 (a Maemo device) to run a hybrid of Android 9 and Windows 10 IoT Core. The thread was titled: “42 is the answer. The question was: can it run Doom?” nokia 42 rom
Nokia devices are notoriously difficult to modify. Unlike brands like Xiaomi or OnePlus, Nokia does not officially provide bootloader unlock codes for most of its mid-range and budget devices. This has severely limited third-party development. Unlike Samsung (Odin) or Xiaomi (Mi Flash Tool),