Unlike standard single-file updates, 4-file firmware splits the data into specific components to ensure a deep clean: BL (Bootloader): Contains the device's bootloader files. AP (System): The main operating system and system applications. CP (Modem): Handles cellular radio and wireless connectivity. CSC (Region):
Android 5.0.1 (Lollipop) was the final official update for the SGH-I337. The 4-file firmware is useful for three main reasons: s4 sgh-i337 firmware 5.0 1 4file