[GUIDE] EFS Backup and Restore for Galaxy Grand i9082 and i9082L

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xenon92

Inactive Recognized Developer
May 20, 2013
762
3,469
shubhangrathore.com
OnePlus 9 Pro
EFS BACKUP AND RESTORE
for
GALAXY GRAND i9082 and i9082L


DISCLAIMER: I am not responsible if you mess up your phone by following steps wrongly. This guide is to help you backup one of the most important partitions on your phone.


This is the FIRST THING that you should do after you root your Galaxy Grand i9082 or i9082L.


This method is ROM INDEPENDENT. It can be performed on any ROM.

Check post #2 below for the EFS BACKUP APP developed by me.

What is so important about EFS and why you SHOULD backup your EFS?


EFS is a system folder in the root directory of your phone that contains very important and basic information about your device's identity like Wi-Fi MAC address, Bluetooth MAC address and the MOST IMPORTANT - IMEI address (nv_data.bin).

Now if this EFS partition accidentally gets corrupted or erased, your phone’s IMEI number will get erased and your device will become completely useless and you won't be able to make voice call further, as the carrier network will not recognize your phone. This can happen for a variety of reasons, sometimes flashing a wrong or corrupted ROM. This kind of damage is not accepted by the service center. Only solution that the service center provides is to replace the motherboard of the device and that costs a lot of $$$!

Only a BACKUP of your EFS can save your phone if something goes wrong with your EFS partition.
(Some of you have already messed up your IMEI. Check Troubleshooting forum for details.)

Below is the correct and the safest method to backup your EFS folder. Copying the "/efs" directory to an external SD card using a root file manager is NOT the correct way as it will mess up the permissions when you restore it back.

NOTE: While some phones have (@k2wl), some of the phones (including mine and @DBZo07) don't have "nv_data.bin" in their "/efs" partition. Even though our IMEI are intact, but this file seems to be missing from "/efs". I am still looking into it as to why it is missing from EFS. I'll update the OP when i am more clear about the reason. Nonetheless, backing up EFS is still an important task and should be performed as soon as you get root permissions on your phone.



BACKUP

1. Open Terminal Emulator.

2. Type the following and press ENTER on your keyboard to grant Terminal Emulator SuperUser permission.
Code:
su

1.png


3. Type the following and press ENTER on your keyboard (case sensitive - so type it just as it is written here)

Code:
dd if=/dev/block/mmcblk0p17 of=/storage/sdcard0/efs.img bs=4096

2.png





If successfully executed, you will see something like this.

3.png




You will get "efs.img" file in your internal memory (sdcard0) of size 20 MB. Move this "efs.img" file to someplace safe - Laptop or Online backup so that it is readily available if you need it.




RESTORE

1. Make sure "efs.img" file is available in your internal memory (sdcard0).

2. Follow steps 1 and 2 from above to grant Terminal Emulator SuperUser permissions.

3. Type the following and press ENTER on your keyboard (case sensitive - so type it just as it is written here)

Code:
dd if=/storage/sdcard0/efs.img of=/dev/block/mmcblk0p17 bs=4096

4. Reboot


You'll have one thing less to worry before trying/flashing something new on your Galaxy Grand i9082.


Don't forget to press Thanks! :good:

Credits:
dr.ketan
 
Last edited:

jayc137

Senior Member
Sep 5, 2012
1,815
865
Mumbai
I myself don't have nv_data.bin file in my /efs directory :confused:

Sent from my GT-I9082 using xda premium
 

xenon92

Inactive Recognized Developer
May 20, 2013
762
3,469
shubhangrathore.com
OnePlus 9 Pro
Glad i could help! :)

I myself don't have nv_data.bin file in my /efs directory :confused:

Sent from my GT-I9082 using xda premium

Apparently, only @k2wl has it. :D

I hope others have it too.

You know this makes things tougher. Not having this file in "/efs" folder. We'll have to figure out other partitions which might contain this IMEI info (mk9efs). This is reference to the new S4 as other devs say that S4 has this info in those partitions.

I own a Note 2 too, and all the files are present under single partition of "/efs". Life is simpler with Note 2!
 
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jayc137

Senior Member
Sep 5, 2012
1,815
865
Mumbai
Can Grand owners confirm the nv_data.bin file in /efs directory ?

Sent from my GT-I9082 using xda premium
 

tharmor

Senior Member
Jun 18, 2013
911
178
Thanks ! So back up should be done only in case of any issues ? Why are people trying to restore the device ?
 

muntinlupa

Senior Member
May 8, 2012
184
19
People are experimenting. I dont want to restore myself since I dont have missing imei

Sent from my GT-N7000 using xda app-developers app
 

xenon92

Inactive Recognized Developer
May 20, 2013
762
3,469
shubhangrathore.com
OnePlus 9 Pro
Thanks ! So back up should be done only in case of any issues ? Why are people trying to restore the device ?

Backup is done BEFORE you face any issues so that you can RESOLVE your issues from the backup that you had when you were not facing any issues.

You DO NOT NEED TO RESTORE until you face some problem regarding EFS. You'll know when to use it when u face problems.
 
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  • 82
    EFS BACKUP AND RESTORE
    for
    GALAXY GRAND i9082 and i9082L


    DISCLAIMER: I am not responsible if you mess up your phone by following steps wrongly. This guide is to help you backup one of the most important partitions on your phone.


    This is the FIRST THING that you should do after you root your Galaxy Grand i9082 or i9082L.


    This method is ROM INDEPENDENT. It can be performed on any ROM.

    Check post #2 below for the EFS BACKUP APP developed by me.

    What is so important about EFS and why you SHOULD backup your EFS?


    EFS is a system folder in the root directory of your phone that contains very important and basic information about your device's identity like Wi-Fi MAC address, Bluetooth MAC address and the MOST IMPORTANT - IMEI address (nv_data.bin).

    Now if this EFS partition accidentally gets corrupted or erased, your phone’s IMEI number will get erased and your device will become completely useless and you won't be able to make voice call further, as the carrier network will not recognize your phone. This can happen for a variety of reasons, sometimes flashing a wrong or corrupted ROM. This kind of damage is not accepted by the service center. Only solution that the service center provides is to replace the motherboard of the device and that costs a lot of $$$!

    Only a BACKUP of your EFS can save your phone if something goes wrong with your EFS partition.
    (Some of you have already messed up your IMEI. Check Troubleshooting forum for details.)

    Below is the correct and the safest method to backup your EFS folder. Copying the "/efs" directory to an external SD card using a root file manager is NOT the correct way as it will mess up the permissions when you restore it back.

    NOTE: While some phones have (@k2wl), some of the phones (including mine and @DBZo07) don't have "nv_data.bin" in their "/efs" partition. Even though our IMEI are intact, but this file seems to be missing from "/efs". I am still looking into it as to why it is missing from EFS. I'll update the OP when i am more clear about the reason. Nonetheless, backing up EFS is still an important task and should be performed as soon as you get root permissions on your phone.



    BACKUP

    1. Open Terminal Emulator.

    2. Type the following and press ENTER on your keyboard to grant Terminal Emulator SuperUser permission.
    Code:
    su

    1.png


    3. Type the following and press ENTER on your keyboard (case sensitive - so type it just as it is written here)

    Code:
    dd if=/dev/block/mmcblk0p17 of=/storage/sdcard0/efs.img bs=4096

    2.png





    If successfully executed, you will see something like this.

    3.png




    You will get "efs.img" file in your internal memory (sdcard0) of size 20 MB. Move this "efs.img" file to someplace safe - Laptop or Online backup so that it is readily available if you need it.




    RESTORE

    1. Make sure "efs.img" file is available in your internal memory (sdcard0).

    2. Follow steps 1 and 2 from above to grant Terminal Emulator SuperUser permissions.

    3. Type the following and press ENTER on your keyboard (case sensitive - so type it just as it is written here)

    Code:
    dd if=/storage/sdcard0/efs.img of=/dev/block/mmcblk0p17 bs=4096

    4. Reboot


    You'll have one thing less to worry before trying/flashing something new on your Galaxy Grand i9082.


    Don't forget to press Thanks! :good:

    Credits:
    dr.ketan
    13
    EFS BACKUP AND RESTORE APP
    for i9082 and i9082L

    Developed by xenon92

    DOWNLOAD


    1.png
    3
    Updated the OP with the EFS Backup App developed by me. An easier way to backup.

    Check post #2
    2
    @xenon92 since I dont have nv_data.bin so the backup method is useless for me?

    Sent from my GT-N7000 using xda app-developers app

    EFS folders contains much more info that just nv_data.bin. Refer OP and Google about it.

    It is advisable to back it up even if you don't see "nv_data.bin" in your EFS as of this moment. I am looking into it. I'll provide you with updates when and if i figure out a few more things that i need.

    Please backup your EFS. Be safe!

    This will work on i9082L as well. OP updated. Verified.
    1
    I am at Gennext rom now.
    Should I go back to official rom first n then backup the efs?


    Sent from my GT-I9082 using XDA Premium 4 mobile app

    You can backup EFS from any ROM.

    Sent from my GT-I9082 using Tapatalk