This firmware is a derived from official 5238. The “Josi” label indicates specific community-applied patches (often credited to a developer named Josi) to improve stability, enable hidden features, and fix bugs present in earlier or official 5238 builds.
Josi identified that the stock 5238 firmware locked certain regional settings, disabled developer menus, and occasionally bricked units when downgrading. His "work" involved: rns 510 firmware 5238 josi work
Offers a faster user interface, quicker navigation, and improved startup times. This firmware is a derived from official 5238
to re-enable your steering wheel controls if they stop working after the update? enable hidden features