Hi,
I have few questions in the EFS are..
i know that its the most important folder in Android system and it contains a lot of info abt the phone, imei etc etc....so my questions are...
1. What are the possible scenarios that EFS will get corrupt and show "BAD IMEI"?
2. Why its happening when we are not doing anything on that particular folder?
3. If a phone is never rooted, but flashes new ROMS, is SGS2 prone to EFS folder corrupt?
I am on KJ2 and not rooted and my phone is never rooted and i dont want to root also..at lease for near future....
Appreciate your help guys.....
Yes, EFS contains IMEI, wifi MAC address, product code, and other very important information, most of these in the nv_data.bin folder.
1) Attempting to change the product code, trying to unlock the phone, etc can result in corrupt data in EFS.
2) Answer is same as above, by using dfifferent methods one might try to change product code (example: to force install a rom or something that's not actually meant for his device)
3) SGS2 is a little prone to efs corruption while flashing roms. Installing official roms might have less risks, but still always backup efs folder because if there is no backup to restore, then the only way out is to take the device to a Samsung service centre.
(Assuming you're rooted, run in a terminal)
To Backup:
su
busybox tar zcvf /sdcard/efs/efs-backup.tar.gz /efs
this backs up efs as a .gz file in your internal usb storage.
To Restore:
su
umount /efs
mke2fs /dev/block/mmcblk0p1
mount -w -t ext4 /dev/block/mmcblk0p1 /efs
busybox tar zxvf /sdcard/efs-backup.tar.gz -C /
reboot
CWM 5.8.0.9 for Huawei MediaPad
WARNING !!! DON'T FORMAT AND DON'T WIPE PARTITIONS USING THESE CWM !
I don't know how much this CWM version improves over the existing one by segler11.
However these build were more aimed at compiling and testing the new kernel sources.
I have tested compiling with both arm-eabi-4.4.0 and arm-eabi-4.4.3 with success on Ubuntu 10.04.
This is experimental, however with the new kernel sources it will just be a matter of time.
I have compiled the kernel included in this CWM recovery image but I didn't recompile the complete image.
I took as base Pyramid CWM 5.8.0.9 and I replaced the files from those found on a stock C232B005 kernel.
As the default build configuration I have used the /proc/config.gz of a C232B005 running kernel.
I have tested this CWM to be able to backup these partitions (I have not tested "restore" yet, just checked the tar archives):
boot.img - 12.582.912 (match 12Mb)
recovery.img - 16.777.216 (match 16Mb)
data.ext4.tar
cache.ext4.tar
system.ext4.tar
custom.ext4.tar
as you can see my hand tweaks to "recovery" require the name of "cust" partition to be "custom" instead but I believe this is a no issue while you backup and restore with the same CWM. Suggestions welcome.
BUGS:
data & time on archives are wrong
mount USB storage does not work
adb not enabled in recovery mode
Formats and Wipes do not work don't use them
The "busybox hwclock" applet doesn't work to set the hardware clock of our device.
The "adb shell" is not active while in CWM recovery, I don't know why and this was my objective so if you have suggestion please help.
As usual flash both "recovery" and "recovery2" partitions using "fastboot" and one of the attached CWM recovery:
Code:
fastboot flash recovery recovery-5.8.0.9-HWMOD-eabi-4.4.3.img
fastboot flash recovery2 recovery-5.8.0.9-HWMOD-eabi-4.4.3.img
fastboot reboot
WARNING !!! DON'T FORMAT AND DON'T WIPE PARTITIONS USING THESE CWM !
.:HWMOD:.
.
Reserved CWM HWMOD
This version seemed to work better for me.Tnx dude!
john9 said:
This version seemed to work better for me.Tnx dude!
Click to expand...
Click to collapse
Thank you for trying it.
Remember to absolutely avoid formatting or wiping partitions.
If you need to format/wipe do it ONLY after reinstalling the original "recovery.img" in both "recovery" and "recovery2" partitions and then reset the device from:
"Settings -> Backup and reset -> Factory reset"
ATTENTION !!! You can safely do a wipe or factory reset only after reinstalling the original recovery image.
Sorry for insisting but I don't want to create problems on users devices and I know those operations will create problems.
.:HWMOD:.
Just a note: I used your 4.4.3 version to try making a nandroid backup last night. Good news and bad news.
This morning I inspected the result using the app Nandroid Browser.
Good: Your CWM does successfully backup /data/data. The other CWM that had been posted here did not do so properly.
Bad: Your CWM also backs up the entire internal SD storage contents inside the folder /data/share. It is customary *not* to include this in a nandroid backup because a) you don't want to inflate the file size unnecessarily, and b) you don't want to overwrite the internal SD on a restore.
Idea: After you fix it, and until you manage to get ADB over USB working, maybe you could add a menu option to make a separate backup archive of internal SD to external SD. This would allow a route to save the internal storage if the device becomes unbootable and requires a data wipe.
cmstlist said:
Just a note: I used your 4.4.3 version to try making a nandroid backup last night. Good news and bad news.
This morning I inspected the result using the app Nandroid Browser.
Good: Your CWM does successfully backup /data/data. The other CWM that had been posted here did not do so properly.
Bad: Your CWM also backs up the entire internal SD storage contents inside the folder /data/share. It is customary *not* to include this in a nandroid backup because a) you don't want to inflate the file size unnecessarily, and b) you don't want to overwrite the internal SD on a restore.
Idea: After you fix it, and until you manage to get ADB over USB working, maybe you could add a menu option to make a separate backup archive of internal SD to external SD. This would allow a route to save the internal storage if the device becomes unbootable and requires a data wipe.
Click to expand...
Click to collapse
Thank you for trying it. I wanted to compile/test a kernel with new sources in a CWM.
Yes, in our device the internal memory "/mnt/sdcard" is also mapped under "/data/share".
Unfortunately I don't have the skills (yet) to build a complete recovery image from scratch,
so what I did was just compiling the kernel part of the recovery image, using the new sources.
Then I simply hex tweaked the "recovery" executable of a 5.8.0.9 Pyramid CWM (HTC Sensation).
So, in conclusion, I have no control over what is copied during the backup process of those partitions.
Though I could control which partition is processed by removing them from "fstab", but there is no gain into it.
We will have to wait somebody with the specific knowledge, or maybe I will have some time to learn once I return from holidays.
.:HWMOD:.
Today i have builded bootable CWM 5.5.0.4 from sources, so now we can adjust all what we need
after_silence said:
Today i have builded bootable CWM 5.5.0.4 from sources, so now we can adjust all what we need
Click to expand...
Click to collapse
well done
HI, can anyone share buckup from working device created by CWM.?
Thanks to all.
Hi,
Is it possible to flash update zips from this CWM recovery (like Beats Audio which is in flashable zip format)?
I don't want to use it for backup-recovery.
...and how about doing wipe cache and wipe dalvik cache?
.dredd. said:
Hi,
Is it possible to flash update zips from this CWM recovery (like Beats Audio which is in flashable zip format)?
I don't want to use it for backup-recovery.
...and how about doing wipe cache and wipe dalvik cache?
Click to expand...
Click to collapse
Haven't tried installing a ".zip" archive from CWM but it should work.
Avoid "wiping" and/or "formatting" partitions, they will be messed up.
hwmod said:
Haven't tried installing a ".zip" archive from CWM but it should work.
Avoid "wiping" and/or "formatting" partitions, they will be messed up.
Click to expand...
Click to collapse
The main reason for use of CWM would be to have the possibility of flashing update zips from CWM... but I am afraid of messing up my device... to understand: no problem if I have to reflash the rom but I would not want to cause mistake which could be repaired only by service.
fastboot is always available if something goes wrong and if you flash cwm you wont be able to install official roms because cwm will overwrite stock recovery
so i was stupid and wiped data and cache - then remembered that it said not to - how do i fix this paperweight? i tried fastbooting all the usual partitions (system, boot, userdata, cache, etc) but still nothing - i can get to fastboot but i cant flash any dload updates. any suggestions are greatly appreciated.
flash stock recovery (2 files) from zipped rom via fastboot and then you should be able to flash stock rom
flashed three different stock recoveries to recovery and recovery2 - still only get the media pad logo twice (flashed androidani intl rom before bricking) cant boot to recovery - think the partition table is screwed. is there a way to create partitions from fastboot, and if so, still would be nice to know the names of the partitions to flash as referenced in tmo stock thread.
byt3b0mb said:
flashed three different stock recoveries to recovery and recovery2 - still only get the media pad logo twice (flashed androidani intl rom before bricking) cant boot to recovery - think the partition table is screwed. is there a way to create partitions from fastboot, and if so, still would be nice to know the names of the partitions to flash as referenced in tmo stock thread.
Click to expand...
Click to collapse
The time needed to reformat and rewrite all the firmware partitions (the first time) will be between 10-15 minutes.
Be patient and give enough time to the device to execute all the needed processes.
When the device finally boot it need to completely regenerate dalvik-cache (the first time).
So try again as instructed above, rewrite "BOTH" partitions named "recovery" and "recovery2", both using the same "recovery.img" file found in the latest stock Huawei firmware.
Now extract the stock Huawei firmware archive on your PC and copy the "dload" folder on an empty formatted SDCard, then insert the SDCard in the MediaPad reboot it and wait until success or failure message.
If you wiped partitions you will have to wait more time (20-30m). It may be that after waiting a while a message about "Encryption not possible" could appear, just say no to encryption and let it reset the device.
It already happened to some of us so hope you are also able to recover your tablet.
thanks i will give it a shot - while it is rewriting partitions, should it be on the huawei logo? or should i see the android / gears turning?
byt3b0mb said:
thanks i will give it a shot - while it is rewriting partitions, should it be on the huawei logo? or should i see the android / gears turning?
Click to expand...
Click to collapse
First time restoration takes time on both moments during the 1st Huawei log and even during animation.
Trying to recover a partition that was wiped takes much longer for the OS to show the error.
When I tried wiping "data" and rebooted the device I recall I went for a long walk and when I returned the device was showing the "Encryption failure / Reset" message (about half an hour later).
So I can only suggest that when you retry you wait at least that amount of time (30 min.) with charger connected, whatever happens leave it alone until it display or ask you do something. Let me know if it works when you have tried.
Download links do not work for me. Can you upload in mediafire please?
I'm just writting this because i've recently had this problem. I managed to sort it out by my own but didn't really find it written anywhere, just bits and pieces scavenged from so many pages that might point to a solution (granted, part of my problem was also finding what was really my problem since the phone stopped working so fast i didn't really had the time to get what happened)
I was trying out swap for my S3, i had created a swap partition in my external card and then followed a guide here from xda to use an app called swapper2 (from market) to enable swap. I must have done something wrong because what it did was format my /efs partition instead as if it was a swap partition. Phone stopped working on the spot, obviously, and wouldn't past samsung's bootscreen.
Also, keep in mind while this worked for me there might be other ways of doing this which may be simpler. This is just what i figured for a solution.
When this helps:
- you accidentally formated your /efs partition
- you have a backup from your /efs partition, files copied with root explorer but not an image you can just flash back to the partition.
- your phone boots to download and to recovery but not to main system (which every tutorial i found seemed to assume to be able to do, i just figured their /efs was not as screwed as mine was)
- your recovery won't mount the /efs partition because it expects it to be ext4 but it's formated to something else and it showing the message:
"e: failed to mount /efs (Invalid argument)"
What doesn't work:
- any kind of standard solution like reflashing a stock rom with odin, with or without .pit file, clear EFS, whatever. It will flash, just won't solve since, apparently, nothing touches the /efs partition because it's so sensible. Even custom recoveries do mount it and apparently format and replace every single other partition but the /efs, which is why i had to do it manually.
Solution:
- simply format the /efs partition back to ext4 and copy your backup files there
What's needed:
- phone drivers installed on the computer. If you had kies installed, this should be covered already. Think you can't have it running while doing this though. Also, for what's worth, i've done this with windows 8 x64.
- updated android sdk tool, mainly adb. If adb is saying device not connected or not found, you may be using an outdated adb.exe (i was). I used adb.exe that came with this software here:
http://forum.xda-developers.com/showthread.php?t=1308546
- root. If your rom isn't rooted you can always flash CF-root from odin in download mode.
http://forum.xda-developers.com/showthread.php?t=1695238
- busybox, am not really sure if i actually got to need this, think so for the formating tool. Can't hurt to have more options though. This is how to install:
http://www.omappedia.com/wiki/Android_Installing_Busybox_Command_Line_Tools
- custom recovery that allows root through adb, i used Philz which is pretty awesome
http://forum.xda-developers.com/showthread.php?t=2002953
- backup files from your /efs. I had mine unzipped and copied to my externalsd while in windows. They were in an efs folder in the sd card. You can push this through adb to the phone later, but i found this way simpler.
How to:
- get into recovery (vol up+home+power button) and plug your phone to the computer. You'll hear an usb connected sound from windows after a bit.
- in recovery, navigate to Mounts and try the "mount /efs". It'll fail. Now, navigate to advanced and "view log". You'll see below that the phone tried to mount a partition and failed, in my case, it had unsucessfully tried to mount /dev/block/mmcblk0p3 which is the partition /efs uses. Take note of this partition name.
- On windows, open a command line (type cmd on you start menu), navigate to where you have adb.exe and type:
adb shell
If all went well, command prompt has changed. You can now issue commands directly to your phone from terminal.
- type "su" to get root permissions. Your command line should change to something like [email protected] Before i had this working i needed to use "Fix permissions". It's an option in the recovery menus on the phone.
- this step is optional but i did it anyway. I created an image of the partition i was going to mess with. If anything went wrong i could always flash it back even if it was broken. By the way, this is what i should have done in the first place instead of just copying /efs files. Would have made the process so much simpler... also, do this if you ever get the phone back working again. Type:
dd if=/dev/block/mmcblk0p3 of=/externalsd/efs.img
The /externalsd/efs.img is just a place you can save stuff to, like your external sd card. You can check what's your mounting point for the card with the command "mount" and look for something relevant like "externalsd".
Also, you may want to copy that efs.img to somewhere else from your phone (like your computer) for safekeeping. Literally remove card from phone, put in computer and copy files there. Notice you may need to reboot phone to recovery if you remove your card so it detects and mounts your card again. Sure, you can also do that from the command line, but it's just easier to reboot the phone.
- Now, we'll format the partition to something your phone can mount (ext4) and is expecting. Be careful, by doing this, you're actually erasing what's left of your partition and replacing by something clean. Type:
mk2fs /dev/block/mmcblk0p3
If all went well, you should see some kind of small report about what was just done.
- To mount this we'll need a mounting point. Type:
mkdir /efs
this will create an /efs folder in root, if it doesn't exist already, and to mount, type:
mount -t ext4 /dev/block/mmcblk0p3 /efs
- if all went well, you now have access to the /efs folder and can copy you files back:
cp -r /externalsd/efs/* /efs
where externalsd was my external sd card mounted on my phone.
- Check if your /efs folder has it's contents properly
ls /efs
I had to reboot the phone to recovery once more at this point and use the "fix permissions" option again.
After this, my phone booted up normally again.
I'm getting Segmentation fault, I guess there's some kinda hardware error on my phone. Gonna take it to Sammy's tomorrow.
Code:
mke2fs -F /dev/block/mmcblk0p11
Segmentation fault
sh-4.2#
Hi thnx for your Guide. I have the EFS problem, after installin 4 diferent rom in 2 hours my imei and baseband lost.( dont now why) i dont have a backup. I was thinking if it take the EFS from another S3 does it work?
Will this work with a Galaxy S4? I545
Enea307 said:
Hi thnx for your Guide. I have the EFS problem, after installin 4 diferent rom in 2 hours my imei and baseband lost.( dont now why) i dont have a backup. I was thinking if it take the EFS from another S3 does it work?
Click to expand...
Click to collapse
No. Read General > Sticky roll-up thread > "IMEI / EFS - Know this stuff"
is normal this output? (i'm meaning the tar.gz unfinding file)
Code:
*****************************************
* BACKUP EFS *
*****************************************
WARNING: Do you wish to Continue? (This will make EFS BACKUP) [Y,N]?Y
--- STARTING ----
--- WAITING FOR DEVICE
--- Backup efs image ---
761 KB/s (9357 bytes in 0.012s)
7 KB/s (39 bytes in 0.005s)
SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_
Creating filesystem with parameters:
Size: 20971520
Block size: 4096
Blocks per group: 32768
Inodes per group: 1280
Inode size: 256
Journal blocks: 1024
Label:
FLEX_BG size: 0
Blocks: 5120
Block groups: 1
Reserved block group size: 0
Created filesystem with 59/1280 inodes and 2432/5120 blocks
40960+0 records in
40960+0 records out
20971520 bytes transferred in 7.271 secs (2884269 bytes/sec)
unknown option -- ZBusyBox v1.19.4-cm9 bionic (2012-02-05 18:40 +0100) multi-cal
l binary.
Usage: tar -[cxtzjahmvO] [-X FILE] [-T FILE] [-f TARFILE] [-C DIR] [FILE]...
Create, extract, or list files from a tar file
Operation:
c Create
x Extract
t List
f Name of TARFILE ('-' for stdin/out)
C Change to DIR before operation
v Verbose
z (De)compress using gzip
j (De)compress using bzip2
a (De)compress using lzma
O Extract to stdout
h Follow symlinks
m Don't restore mtime
exclude File to exclude
X File with names to exclude
T File with names to include
2684 KB/s (9962352 bytes in 3.623s)
2805 KB/s (20971520 bytes in 7.299s)
remote object '/sdcard/SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.tar.gz' does n
ot exist
7-Zip (A) 4.65 Copyright (c) 1999-2009 Igor Pavlov 2009-02-03
Scanning
SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.tar.gz: WARNING: Impossibile trovare
il file specificato. [COLOR=Red](impossible to find the specify file)[/COLOR]
Creating archive SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.zip
Compressing getprop.txt
Compressing SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.raw.img
Compressing SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.tar.md5
WARNINGS for files:
SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS.tar.gz : Impossibile trovare il file
specificato.[COLOR=Red] (impossible to find the specify file)[/COLOR]
----------------
WARNING: Cannot find 1 file
-
-
Finished. Output file is SM-N9000ZWEXXV_N900XXUCMJ3_RF1DA111EAY_EFS BACKUP
Premere un tasto per continuare . . .
well in the zip there are only the txt + md5 + .raw.img
Thanks for this great tutorial. It was my final step to recover my efs partition, without any backup. I copied the efs folder from another device and modified the files according my devices info (bluetooth mac, serial etc). Worked great on my SGS4
By the way I had the same error:
Code:
mke2fs /dev/block/mmcblk0p10
Segmentation fault
You get this error if you run adb shell when you booted to your ROM.
You need to run adb shell in recovery mode
Great tutorial but i hope you can help me, I can't seem to properly find the SDcard. When I type cp -r /externalsd/efs/* /efs
it comes back with cp: can't stat '/sdcard/efs*' : No such file or directory
I cleared my whole sdcard card except for efs directory. I also tried sdcard instead of externalsd but same thing.
I am getting stuck trying to fix this as I have a boot loop or corrupt /efs or something. I have tried to get my phone working by installing my ROM ( Omega v58 ) and also by trying to flash the latest stock 4.3 through Odin v3.09. I havent tried total stock 4.0.3 yet. No matter what I have done though I can't get past the boot logo ( or the walking Omega droid ). My phone just sits there and hangs
I have followed your steps and I have Philz ( 6.07.9.19 ) installed ( but not busybox unless it is sat there somehow from the Omega install ) but when i try to get adb shell running nothing happens or works..as you can see
What am i doing wrong? OR is my phone totally borked?
hi..
Blackwatch said:
I am getting stuck trying to fix this as I have a boot loop or corrupt /efs or something. I have tried to get my phone working by installing my ROM ( Omega v58 ) and also by trying to flash the latest stock 4.3 through Odin v3.09. I havent tried total stock 4.0.3 yet. No matter what I have done though I can't get past the boot logo ( or the walking Omega droid ). My phone just sits there and hangs
I have followed your steps and I have Philz ( 6.07.9.19 ) installed ( but not busybox unless it is sat there somehow from the Omega install ) but when i try to get adb shell running nothing happens or works..as you can see
What am i doing wrong? OR is my phone totally borked?
Click to expand...
Click to collapse
I have successfully fix my efs partition follwing this thread.
you are receiving such message in cmd. I faced it too.
Sol: Use Philoz Recovery 5.0.
Fix permissions.
there you are.. done..
Philz 6.0 do not have an option for "fix permission".
hope it helps..
I wrote a script that attempts to recover your nv_data.bin from a corrupted EFS partition for the i9300. Thus if you don't have a backup and your EFS is corrupt, try the script. The script is still in Alpha phase and may not work for other devices. Feedback would be much appreciated.
You can find the script at: https://github.com/chriscz/efs_recover
I dont have /efs backed up
Hi ,
If i dont have /efs backed up , can I copy any other mobile (same model) efs data to my mobile and try?
Thanks and Regards
Vamshi Pulumati
vamshipulumati said:
Hi ,
If i dont have /efs backed up , can I copy any other mobile (same model) efs data to my mobile and try?
Thanks and Regards
Vamshi Pulumati
Click to expand...
Click to collapse
No, it won't work and trying to clone another imei is illegal.
boomboomer said:
No, it won't work and trying to clone another imei is illegal.
Click to expand...
Click to collapse
How to register for a new IMEI ? Is it possible?? Could you please help me with any site or link?? I don't want to replace motherboard..
Any help are highly appreciated.
No, it isn't possible and discussion about changing imei is banned on xda.
Take your phone to a service centre and pay then to recode it for you, make sure it works on 4.3 before you pay.
boomboomer said:
No, it isn't possible and discussion about changing imei is banned on xda.
Take your phone to a service centre and pay then to recode it for you, make sure it works on 4.3 before you pay.
Click to expand...
Click to collapse
Hey I would like to tell you that a miracle happened for my S3. Yesterday i tried to do same as per in this guide. After taking backup of broken efs backup i tried to clear the efs folder with this command "mk2fs /dev/block/mmcblk0p3"
After that i just flashed 4.4.4 based stock ROM and somehow phone booted up perfectly. No network issues. Bluetooth wifi sim card everything works. IMEI & Serial No is there. But when i'm checking network unlock status it is showing as everything locked. But still I can use everything... I'm amazed.!!!!
Do you have any idea how this happened??
@boomboomer
Same problem with a Samsung gt-i9070 - Galaxy S Advance
Hi!
My i9070 has the same problem, but when i run the command: "mke2fs /dev/block/mmcblk0p3" shows the "Segmentation fault" error message.
Some one can help?
Thanks.
Bro U stated to format but How to format /efs partition
/efs not backed up
boomboomer said:
No, it won't work and trying to clone another imei is illegal.
Click to expand...
Click to collapse
I Dont have efs backed up and I also have formatted efs partition from adb shell and using that Dev type commands now i am in factory mode and my network is not working please give me any solution.
kaynpayn said:
I'm just writting this because i've recently had this problem. I managed to sort it out by my own but didn't really find it written anywhere, just bits and pieces scavenged from so many pages that might point to a solution (granted, part of my problem was also finding what was really my problem since the phone stopped working so fast i didn't really had the time to get what happened)
I was trying out swap for my S3, i had created a swap partition in my external card and then followed a guide here from xda to use an app called swapper2 (from market) to enable swap. I must have done something wrong because what it did was format my /efs partition instead as if it was a swap partition. Phone stopped working on the spot, obviously, and wouldn't past samsung's bootscreen.
Also, keep in mind while this worked for me there might be other ways of doing this which may be simpler. This is just what i figured for a solution.
When this helps:
- you accidentally formated your /efs partition
- you have a backup from your /efs partition, files copied with root explorer but not an image you can just flash back to the partition.
- your phone boots to download and to recovery but not to main system (which every tutorial i found seemed to assume to be able to do, i just figured their /efs was not as screwed as mine was)
- your recovery won't mount the /efs partition because it expects it to be ext4 but it's formated to something else and it showing the message:
"e: failed to mount /efs (Invalid argument)"
What doesn't work:
- any kind of standard solution like reflashing a stock rom with odin, with or without .pit file, clear EFS, whatever. It will flash, just won't solve since, apparently, nothing touches the /efs partition because it's so sensible. Even custom recoveries do mount it and apparently format and replace every single other partition but the /efs, which is why i had to do it manually.
Solution:
- simply format the /efs partition back to ext4 and copy your backup files there
What's needed:
- phone drivers installed on the computer. If you had kies installed, this should be covered already. Think you can't have it running while doing this though. Also, for what's worth, i've done this with windows 8 x64.
- updated android sdk tool, mainly adb. If adb is saying device not connected or not found, you may be using an outdated adb.exe (i was). I used adb.exe that came with this software here:
http://forum.xda-developers.com/showthread.php?t=1308546
- root. If your rom isn't rooted you can always flash CF-root from odin in download mode.
http://forum.xda-developers.com/showthread.php?t=1695238
- busybox, am not really sure if i actually got to need this, think so for the formating tool. Can't hurt to have more options though. This is how to install:
http://www.omappedia.com/wiki/Android_Installing_Busybox_Command_Line_Tools
- custom recovery that allows root through adb, i used Philz which is pretty awesome
http://forum.xda-developers.com/showthread.php?t=2002953
- backup files from your /efs. I had mine unzipped and copied to my externalsd while in windows. They were in an efs folder in the sd card. You can push this through adb to the phone later, but i found this way simpler.
How to:
- get into recovery (vol up+home+power button) and plug your phone to the computer. You'll hear an usb connected sound from windows after a bit.
- in recovery, navigate to Mounts and try the "mount /efs". It'll fail. Now, navigate to advanced and "view log". You'll see below that the phone tried to mount a partition and failed, in my case, it had unsucessfully tried to mount /dev/block/mmcblk0p3 which is the partition /efs uses. Take note of this partition name.
- On windows, open a command line (type cmd on you start menu), navigate to where you have adb.exe and type:
adb shell
If all went well, command prompt has changed. You can now issue commands directly to your phone from terminal.
- type "su" to get root permissions. Your command line should change to something like [email protected] Before i had this working i needed to use "Fix permissions". It's an option in the recovery menus on the phone.
- this step is optional but i did it anyway. I created an image of the partition i was going to mess with. If anything went wrong i could always flash it back even if it was broken. By the way, this is what i should have done in the first place instead of just copying /efs files. Would have made the process so much simpler... also, do this if you ever get the phone back working again. Type:
dd if=/dev/block/mmcblk0p3 of=/externalsd/efs.img
The /externalsd/efs.img is just a place you can save stuff to, like your external sd card. You can check what's your mounting point for the card with the command "mount" and look for something relevant like "externalsd".
Also, you may want to copy that efs.img to somewhere else from your phone (like your computer) for safekeeping. Literally remove card from phone, put in computer and copy files there. Notice you may need to reboot phone to recovery if you remove your card so it detects and mounts your card again. Sure, you can also do that from the command line, but it's just easier to reboot the phone.
- Now, we'll format the partition to something your phone can mount (ext4) and is expecting. Be careful, by doing this, you're actually erasing what's left of your partition and replacing by something clean. Type:
mk2fs /dev/block/mmcblk0p3
If all went well, you should see some kind of small report about what was just done.
- To mount this we'll need a mounting point. Type:
mkdir /efs
this will create an /efs folder in root, if it doesn't exist already, and to mount, type:
mount -t ext4 /dev/block/mmcblk0p3 /efs
- if all went well, you now have access to the /efs folder and can copy you files back:
cp -r /externalsd/efs/* /efs
where externalsd was my external sd card mounted on my phone.
- Check if your /efs folder has it's contents properly
ls /efs
I had to reboot the phone to recovery once more at this point and use the "fix permissions" option again.
After this, my phone booted up normally again.
Click to expand...
Click to collapse
I have restored my s6 edge by following this method. The EFS partition name is "sda3" for s6 edge if anyone want to restore s6 edge. There is typo in command "mk2fs /dev/block/mmcblk0p3" it should be mke2fs i think.
After restoring EFS my phone recovered from boot loop. But the imei is still invalid. Do you know any method to repair imei for s6 edge?. Thank You
---------- Post added at 02:18 PM ---------- Previous post was at 02:14 PM ----------
Blackwatch said:
I am getting stuck trying to fix this as I have a boot loop or corrupt /efs or something. I have tried to get my phone working by installing my ROM ( Omega v58 ) and also by trying to flash the latest stock 4.3 through Odin v3.09. I havent tried total stock 4.0.3 yet. No matter what I have done though I can't get past the boot logo ( or the walking Omega droid ). My phone just sits there and hangs
I have followed your steps and I have Philz ( 6.07.9.19 ) installed ( but not busybox unless it is sat there somehow from the Omega install ) but when i try to get adb shell running nothing happens or works..as you can see
What am i doing wrong? OR is my phone totally borked?
Click to expand...
Click to collapse
You don't have to run "su" command. "#" shows you already have root access.
I made the silly mistake of not doing a complete backup of my EFS folder before flashing my cellphone with a custom ROM:crying:
and now my EFS folder is empty;if I delete it with ES File Manager (my phone is rooted) as soon as I reboot the phone, the EFS folder is created again,
but it is empty.I'm able to make and receive phone calls,send and receive sms,use wireless,bluetooth and gps,but if I dial *#06# my IMEI is blank.
With Galaxy Tool Box (the Rom installed it) --> Device Information I can see my correct IMEI (same number write in the battery slot).
I have a CWM backup and these files are in the backup folder: .android_secure.vfat.tar / boot.img / cache.rfs.tar / data.rfs.tar / nandroid.md5 / system.rfs.tar
Could one of these files help me restore my EFS folder (with all the files ofc)? Even the Product code is gone (KIES doesn't recognize the device)
I've got the the original stock firmware for my italian GT-S 5830i ,and I've tried to flash it with ODIN (PDA/MODEM/CSC) but that was pointless.
Thanks in advance for your time and consideration.
Have a nice day.
[email protected] said:
I made the silly mistake of not doing a complete backup of my EFS folder before flashing my cellphone with a custom ROM:crying:
and now my EFS folder is empty;if I delete it with ES File Manager (my phone is rooted) as soon as I reboot the phone, the EFS folder is created again,
but it is empty.I'm able to make and receive phone calls,send and receive sms,use wireless,bluetooth and gps,but if I dial *#06# my IMEI is blank.
With Galaxy Tool Box (the Rom installed it) --> Device Information I can see my correct IMEI (same number write in the battery slot).
I have a CWM backup and these files are in the backup folder: .android_secure.vfat.tar / boot.img / cache.rfs.tar / data.rfs.tar / nandroid.md5 / system.rfs.tar
Could one of these files help me restore my EFS folder (with all the files ofc)? Even the Product code is gone (KIES doesn't recognize the device)
I've got the the original stock firmware for my italian GT-S 5830i ,and I've tried to flash it with ODIN (PDA/MODEM/CSC) but that was pointless.
Thanks in advance for your time and consideration.
Have a nice day.
Click to expand...
Click to collapse
The EFS Partition doesn't contain any files, it only contains raw HEX Data so it is normal for it to be empty. I recommend you install a custom kernel then flash the stock ROM via Odin as this has worked for me in the past.
I was wondering if the so called NV 'memory' is actually stored on the file system as well. It is normally shortened as NV or NV-items.
I see there is /efs in the file system. So the question is, is NV stored somewhere in file system too?
idoit said:
I was wondering if the so called NV 'memory' is actually stored on the file system as well. It is normally shortened as NV or NV-items.
I see there is /efs in the file system. So the question is, is NV stored somewhere in file system too?
Click to expand...
Click to collapse
You can check with many imei or EFS or partitions backup tool developers, NV Items are stored in modemst1 and modemst2 partitions for MSM89xx. It is changed to mdm9kefs1 mdm9kefs2 and mdm9kefs3 for APQ80xx +MDM96xx based models. Sammy android userdata have very litmited items mapping with "efs", only BT and WiFi mac address are too far from hundreds of NV items for a normal android phone.
Thank you @Azlun.
So now a simple question: How come I can read and write on modemst1 and modemst2 partitions without having root access? (My phone is absolutely untouched).
No,I think no way in generally in case you have a locked bootloader and unrooted.
Even,in some case, you are lucky to own a motorola phone, and know its SPC, then you can use PC tools such as QPST to read/write NV items by items after boot from bootloader BP tool mode. No other workaound as my knowlege since partition s are only accessable by root user.