Related
Hi all, probably mine is a noob question, since in android I'm quite a noob. I've been using gentoo for years though so I'm somehow confident with the shell and I'd love it to work on it on my rooted sgs2
So, basically, I searched but I didn't find (/me fool). When asking for write permission everyone is talking about /system, but not / in general. Is there a reason? If I need to copy&paste or just create a file directly in / how can I do?
Giving a #mount command shows me only this about "/" :
rootfs on / type rootfs (ro,relatime)
so there is no indication about a /dev/block adress or a "real fs" information (which for what I know is ext4). Also those informations looks like a "pseudo-filesystem" partition, like sysfs or fusefs for instance.
Looking at the rest of the "#mount" output (aka "cat /proc/mounts") I see the only other partition mounted in ro is /system, but it has a block device association and I can remount it in rw easily. Not the same with /
Can anyone clarify me please? Is there a way to mount / in rw?
This is because that's where we want to use. The system area is where modifications of the device (done by people who should know exactly what they are doing; e.g changing build.prop codes) is made. It can easily be made r/w but only if your device is rooted and in many cases S-OFF'ed. If you have root (and for some devices S-OFF), then you can just use a file explorer (which supports root functions e.g Root Explorer) to mount it as r/w (this is the easiest way).
Yes, my phone is rooted and S-OFF'd and everything's fine, I have no particular problem to fix, just wondering.
So what if anything goes corrupted in / (outside /system, /data or any other separate partition) and we need to restore it or just create a script or anything changing permissions or writing data on the / partition? Btw: for what I know about linux, the root partition (I mean "/" not "/root") must be a "real partition" with a proper fs and mount point, and not anything cached somewhere. Guess it must be the same in android too. So, where is it?
johnnystuff said:
Yes, my phone is rooted and S-OFF'd and everything's fine, I have no particular problem to fix, just wondering.
So what if anything goes corrupted in / (outside /system, /data or any other separate partition) and we need to restore it or just create a script or anything changing permissions or writing data on the / partition? Btw: for what I know about linux, the root partition (I mean "/" not "/root") must be a "real partition" with a proper fs and mount point, and not anything cached somewhere. Guess it must be the same in android too. So, where is it?
Click to expand...
Click to collapse
For Android (about corruption for the first question), people usually just reflash the rom since you wouldn't be able to boot the phone (at least fully) to be able to replace a missing file(s). Where is "/" you ask, if you open Root Explorer that's where you'll be.
I know where is "/" in that sense, I meant where is the partition or the mount point
anyway..... not a big issue. I must deduce in android, in any present past and future device, the /efs directory is mounted on a separate partition. All my guessing came mostly from that point, since I wanted to backup and most of all _restore_ that dir using the shell. Again, I don't need it now, I did my backup and I hopefully will never need a restore. Most of all in my sgs2 /efs is on a rw partition, so no issue at all even in case of deep trouble (/efs deletion).
And yep, I know about EFS Pro and similar tools, but wanted to try the sh way and to understand something more of android in general
why is the trouble EFS deletion? what is EFS partition for?
Sent from my Nexus S using XDA App
Speaking on this subject, I have tried but cannot remove the file "/sys/devices/virtual/sec/ts/touchkey_led" (trying to turn off lights behind capacitive buttons).
Does anyone know how to move/delete this?
No, led hack doesn't work on my device if you are wondering.
why is the trouble EFS deletion? what is EFS partition for?
Click to expand...
Click to collapse
/efs is where your IMEI and other critical (and legal) information of your device are stored. You should backup it as soon as you root your phone, before any other mod. Hence comes the troubles, since if you delete it for any reason, you are in deep troubles, expecially if you didn't backup it.
I have tried but cannot remove the file "/sys/devices/virtual/sec/ts/touchkey_led"
Click to expand...
Click to collapse
I'm not totally sure about what I'm saying on android, but on linux /sys is an in-memory filesystem, meaning it is generated by the system after (at) boot and it's where all your device are linked in for the kernel, so it basically manged by the kernel itself. That could be the reason why you cannot delete anything in there. But again, I'm somehow guessing so, wait for someone else to confirm (or deny)
johnnystuff said:
That could be the reason why you cannot delete anything in there. But again, I'm somehow guessing so, wait for someone else to confirm (or deny)
Click to expand...
Click to collapse
Actually you can delete items in there... but they will just be re-created .
Hello xda!!
I own a GS3 i9300 and im a noob at android's and codings.
When I start the phone, I have no IMEI, cant see any carrier, I don't have lock screen and I don't have that power menu.
The only method I am using to correct this whole issue is :
-Go into Root Explorer
-Go to "/system/efs
-Copy the whole "Efs" directory
-Paste on /Efs
and voilá, it starts to work. I get everything back. The problem is I want this to be permanent, like a normal Phone. I have a rooted stock Rom. This might be simple to solve but I really don't know.
Thanks
raixa said:
Hello xda!!
I own a GS3 i9300 and im a noob at android's and codings.
When I start the phone, I have no IMEI,
Restore your backed up EFS folder .
Fix Permissions see sticky .
IMEI/ EFS see multiple posts on the subject .
jje
Click to expand...
Click to collapse
I've used fix permissions but i cant restore any EFS cause EFS pro says this "efs pro can't locate mount point"
Should I flash a new firmware and restore the EFS?
Just flashed stock firmware and Efs problem still continue.
I have the EFS backup.
The problem is that every single time my device reboots, the EFS folder appears, but has nothing inside. I can´t change permissions on the folder because root explorer wont let me.
Any solution?
raixa said:
Just flashed stock firmware and Efs problem still continue.
I have the EFS backup.
The problem is that every single time my device reboots, the EFS folder appears, but has nothing inside. I can´t change permissions on the folder because root explorer wont let me.
Any solution?
Click to expand...
Click to collapse
No firmware (stock or custom) modifies efs partition when flashed. If it was broken before, it will be when you flash stock firmware also.
You will need root access to fix this problem. If I had this problem I would flash a rom with root, busybox and as no other mods to be on the safe side (or root and install busybox on the stock one). Try to make a new file in /efs (use a file manager with root access) and reboot . The file should be there after restart. If it is the the phone is ok and you will just need to restore the backup. If it isn't you will need help from someone with more experience.
Thanks dav_991.
Just tried your solution but after the restart, there's nothing on /efs again.
One thing I noticed is that when I enter /efs folder its "mounted like R/W", but if I switch to "Mount R/O" and I get out of Root explorer, some files appear on the Efs folder. Thing is every time I restart the phone it appears mounted as R/W.
raixa said:
Thanks dav_991.
Just tried your solution but after the restart, there's nothing on /efs again.
One thing I noticed is that when I enter /efs folder its "mounted like R/W", but if I switch to "Mount R/O" and I get out of Root explorer, some files appear on the Efs folder. Thing is every time I restart the phone it appears mounted as R/W.
Click to expand...
Click to collapse
On my s3 /efs is mounted as rw by default. I do not think that this is related to your problem. To see which partition (and how) is mounted as /efs, in terminal emulator type (and grant permission when asked):
Code:
su
cat /proc/mounts | grep /efs
It should look like:
Code:
/dev/block/mmcblk0p3 /efs ext4 rw,nosuid,nodev,noatime,barrier=1,journal_async_commit,data=ordered 0 0
Yot could also post the files that are in the efs partition before and after you mounted as ro with command:
Code:
ls -la /efs >/sdcard/efs_list.txt
In phone memory you will get a file named efs_list.txt with the names of the files (every time you run the command the file is overriten, take this in consideration. Also be careful not to misspell something, you could overrite something you need).
I did some more research and ended up being the /Efs folder that wasn't mounted.
Managed to solve it by the terminal, adding the SU command.
Thanks everyone.
Best Regards,
Luis Matos
Hey. I tried this swapper2 app from the market and this little thing formated some partition from my phone thinking it was the swap one. Now phone won't go pass the samsung logo with sound.
I can get into recovery and into download mode. I tried flashing a brand new pcodin EMB5 flash, with no .pit nor repartition. No go. Rooted with CF-root (which also gives me CWM recovery). Recovery gives me the error: can't mount /efs so i'm guessing my /efs got formated. I have a backup made by copying the /efs files to another folder when all was working. What i'm guessing needs to be done is get my /efs partition created again (or at least mounted, not sure it's state) so i can copy it's contents there again.
What's the best way of doing this? I've seen people saying they can just use adb, mount /efs with the commands:
mke2fs /dev/block/mmcblk0p1
mount -w -t ext4 /dev/block/mmcblk0p1 /efs
and copy it's contents. But i need my phone to boot first to use adb, right? Doesn't seem to be working from recovery or download mode.
Would reflashing with odin using the pit file, repartition option or even the Clear ESF option work? I'm not very clear about what "clear efs" does.
Any other ideas?
Thanks!
EDIT:
I've managed to solve my problem, phone's up and running again. I'll post the entire process later for anyone else, god knows i'd have loved to see this written somewhere instead of all the inconclusive bits and pieces scavenged around the internet.
Update:
On recovery (CWM) /efs is the only partition it can't mount.Log says
"w:failed to mount /dev/block/mmcblk0p3 (invalid argument)
Error mounting /efs"
From what i understand, mmcblk0p3 is the /efs partition. Would restoring an image of mmcblk0p3 work? I have my /efs contents but not an image of it. Would it be possible to get an image from some other phone, restore it on mine and just replace it's contents later?
If so, would anyone be so kind to send me one image of mmcblk0p3 for the gt-i9000?
Thank you.
adb works from recovery.
no, no one will send you their efs folder
Yes, i managed to get adb working with recovery. i figured as much. to be honest, but i though if someone had an image from a broken phone or simply wouldn't mind sharing, it wouldn't hurt to ask since i've seen them around for other phones before. I couldn't care less about other phone's contents, just want to replace them with mine.
I will try to recreate this partition via adb with fdisk or something. Can anyone share the details of the mmcblk0p3, like size, blocks, etc?
Any other ideas are also appreciated.
efs contains fragile data, like the IMEI. Having it, it is relatively easy to unblock the phone locked as the result of stolen one claim.
I doubt if someone would share this content, first. Second, any effort related with IMEI cloning is not welcomed here.
spamtrash said:
efs contains fragile data, like the IMEI. Having it, it is relatively easy to unblock the phone locked as the result of stolen one claim.
I doubt if someone would share this content, first. Second, any effort related with IMEI cloning is not welcomed here.
Click to expand...
Click to collapse
I'm well aware and not trying to clone anything. But I'll change my request then: think it's possible for someone to extract the efs image, mount it elsewhere (in linux or something, should be an ext4, right?) delete it's files, save and send it to me? The partition structure should still be there (which is what i want) but no delicate files for me to use. I can then restore it to my phone, hopefully mount it manually in adb and copy my /efs contents.
Think this would work?
Thank you
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 should start off by mentioning im completely new to rooting and custom roms (or even UNIX for that matter)
Just today I've just flashed a CM 10.1 rom onto my LG Optimus 2x.
In the process my phone has lost its IMEI, and for that reason i cannot connect to any mobile network.
In the 'about phone' section of the settings, it shows IMEI as unknown and Baseband as unknown.
Ive learned that this may have to do with a corrupted EFS folder/partition. I didnt make a backup of this folder (the guides i were following didnt
mention that i should have done that)
Now I'm trying to follow along with this guide to recover my IMEI
http://forum.xda-developers.com/showthread.php?t=1264021
The problem is i don't even find the /efs folder in both the terminal emulator or this app ive downloaded "ES File explorer"
Does it mean its been deleted? Ive read that it may need to be mounted so i found this command somewhere on XDA to use
su
mke2fs /dev/block/mmcblk0p3
mount -w -t ext4 /dev/block/mmcblk0p3 /efs
Click to expand...
Click to collapse
The first line worked in the terminal emulator, but when i tried entering the second line i get an error 'mount: No such file or directory'
What am i doing wrong and how screwed am i?
Have you managed sort this out?
I have exactly the same problem on 4X HD.
billion_boi said:
I should start off by mentioning im completely new to rooting and custom roms (or even UNIX for that matter)
Just today I've just flashed a CM 10.1 rom onto my LG Optimus 2x.
In the process my phone has lost its IMEI, and for that reason i cannot connect to any mobile network.
In the 'about phone' section of the settings, it shows IMEI as unknown and Baseband as unknown.
Ive learned that this may have to do with a corrupted EFS folder/partition. I didnt make a backup of this folder (the guides i were following didnt
mention that i should have done that)
Now I'm trying to follow along with this guide to recover my IMEI
http://forum.xda-developers.com/showthread.php?t=1264021
The problem is i don't even find the /efs folder in both the terminal emulator or this app ive downloaded "ES File explorer"
Does it mean its been deleted? Ive read that it may need to be mounted so i found this command somewhere on XDA to use
The first line worked in the terminal emulator, but when i tried entering the second line i get an error 'mount: No such file or directory'
What am i doing wrong and how screwed am i?
Click to expand...
Click to collapse
gergog said:
Have you managed sort this out?
I have exactly the same problem on 4X HD.
Click to expand...
Click to collapse
No i haven't Please let me know if you have figured something out yourself
billion_boi said:
No i haven't Please let me know if you have figured something out yourself
Click to expand...
Click to collapse
I have donwloaded an offcial firmware and flash that. The factory reset was also needed.
Now my mobile is working, but i still do not have efs folder.sometimes i feel that LG phones store that some other way. Do you have efs folder?
/G