It is easy one click tool.
Here is the link or here to the tool but just to be sure if it is down I uploaded the tool and I post the explanation here also.
No credits to me but to the creators. I tested it on my tab and pc (windows7) and it works without any problem.
It finds the correct partition where the EFS is (dev/block/mmcblk0p3) on our device.
What is EFS:
EFS folder is the very sensitive system folder that contains Phone-specific information such as the IMEI, wireless devices MAC addresses, product code, and much more. If this thing not handled properly, can turn your device completely useless as it will no longer be recognized by your carrier.
Problem is, flashing custom ROMs sometime can corrupt contains within EFS folder. That’s why backing up EFS folder is very important if you love to flash new ROM. Good thing is, Developer develop a tool that can backup and restore ‘EFS’ folder of your device easily called EFS Pro. No need to say, this tool require a rooted device.
Features of the tool
- Supports Backup and Restore of Partition Image (*.img) and Compressed TAR Archive (*.tar) formats.
- Automatically detects saved EFS Backups on Device and PC for hassle free restoring.
- Re-Scan option to refresh Backup list for restoring Backups.
- Automatically Re-Mounts ‘EFS’ folder with Read/Write permissions during restore for users ‘stuck’ with Read Only permissions.
- Automatic detection and prompting of Mass Storage Mode.
- Automatic detection and termination of SAMSUNG Kies application on startup.
- Supports Multiple Backup handling.
- Option to Format ‘EFS’ partition before restoring an EFS Backup.
- Displays various Device, ROM and BusyBox related information on startup.
- Attempt NV Recovery – Restores NV Data from ‘*.bak’ files if they exist to fix corrupt or incorrect IMEI number.
- Repair NV Data – Repairs NV Data file ownership to fix ‘Unknown Baseband’ and ‘No Network / Signal’.
- AUTOMATIC ‘/efs’ partition location detection to add support for many more including future devices.
- Hashing of Partition Image Backups to verify the data written.
Download EFS Pro v1.9.12
Now, run EFS Pro.exe file and follow the onscreen instruction to backup or restore your device’s ‘/efs’ folder.