Sm-g920f Nv Data File

su
dd if=/dev/block/platform/155a0000.ufs/by-name/EFS of=/sdcard/efs.img

If your SM-G920F is currently showing "Unknown Baseband" or has a null IMEI, you are likely desperate for a fix. Here is the professional approach versus the risky approach:

The Risky Approach (Not Recommended):

The Professional Approach (Recommended): sm-g920f nv data file

NV = Non-Volatile memory.
The NV data file contains device-specific calibration and configuration data stored in the EFS (Encrypted File System) partition. su dd if=/dev/block/platform/155a0000

If you already have a backup, restoration is straightforward: If your SM-G920F is currently showing "Unknown Baseband"

Important: After restoration, perform a factory reset from recovery, then flash the same stock firmware (Android 7.0) via Odin to re-sync the modem.

If you have no backup, you face a much harder path: