If you are a Samsung Galaxy phone user, and would like to explore the limits of your device by rooting, installing custom recoveries, custom ROMs, Mods and other tweaks should conscious about EFS data. Flashing an invalid custom ROM, invalid recovery, invalid mod or applying any inappropriate things can corrupt your device’s EFS data, so you will lost all the connectivity features of your device. That is, you cannot use SIM card, Wi-Fi or Bluetooth, etc.
Basically, EFS data (Encrypting File System) contains all the information about your Samsung Galaxy’s IMEI, Wireless MAC address, product code, baseband version, system ID and NV data. Usually this data remain safe, but rooting and tweaking your device can corrupt EFS data and can lead to many issues.
However, there is no need to worry about it, you can easily backup and restore EFS data on your Samsung device and there are several methods for that. An XDA member ricky310711 has come up with a simple tool called “Samsung Tool” that lets you backs up and restores EFS on Samsung Galaxy series phones including the new Galaxy S5.
Requirements: Your Galaxy S5 must be rooted and Samsung Tool installed.
1. Download Samsung Tool from here.
2. Copy the downloaded Samsung Tool APK file to your phone and install it.
3. Once installed run it from the app drawer and give it the root permissions.
4. Now, select whether you want to backup or restore EFS (you can backup EFS on internal or external SD card).
5. Select the storage and it will do the job.
Note that, Samsung Tool also supports following Samsung devices: GT-I9300, GT-I9305, GT-I9505, GT-I9500, GT-N7100, GT-N7105, SM-N900, SPH-L710, and SM-N9005. Hope that you find this guide helpful.