FORUMS
Remove All Ads from XDA

 View Poll Results: Did This Work For You

Worked
 
8 Vote(s)
88.89%
Did Not Work
 
1 Vote(s)
11.11%

[GUIDE] Fix Can't Mount /EFS Which Wont Let You Run Jelly Bean

41 posts
Thanks Meter: 16
 
By XylerSmith, Member on 2nd September 2013, 10:01 PM
Post Reply Email Thread
After I flashed a couple roms I couldn't boot jelly bean anymore and I noticed the error in recovery: E:\ Cant Mount /efs, when installing. But I could still boot ICS but not jellybean. I still had my IMEI and could make calls but could not boot jelly bean because it couldn't mount.

How does this issue happen?
Sometimes when installing a rom something goes wrong and it changes the partition type of /efs making it unable to be mounted. The partition is usually from ext4 to swap.

Most likely this will work on your phone but if it doesn't and your phone stops working I am not responsible.

If your like me and you couldn't get jelly bean to work then flash your device back to ics and it should boot. Once your booted inside of ics we can start the process.

Pre-Setup:
1. Be rooted and have a custom recovery installed.
2. Be on Ics and it boots.
3. Your need to have a Jelly Bean rom like Cyanogenmod on your sdcard.
4. Have adb installed on your pc and usb debugging on in your phone/tab.

Now that that's done its time to start.
Part One:
1. Boot into recovery.
2. We need to find the efs block location.
3. Go to mounts and select efs
4. It should say unable to mount
5. Go to advance and make a recovery.log
6. Put that file on your computer and open it.
7. Look through the file and you should fine something like this around the beginning of the file:
E:Unable to mount '/efs'
I:Actual block device: '/dev/block/mmcblk0p3', current file system: 'swap'
My location is /dev/block/mmcblk0p3 But yours could be different! Most likely the difference will be instead of it ending with a 3 it will be a different number. I will be saying /dev/block/mmcblk0p3 if yours is different just change it to your location.

*WARNING* Sometimes when you copy paste into adb it will auto run the command without you pressing enter. If your location is different then mine and you copy past and it auto runs it could be BAD so to be careful if you want to copy past. Copy the command paste it into Google make the change and copy that and paste into adb

Part Two:
1. When your inside recovery connect your phone to your computer and get into a adb shell. (Sometimes it will take awhile for adb to recognize your device so be patient.)
2. Once you have adb access its time to start entering the commands.(Again my location may be different the yours! Most likely the difference will be instead of it ending with a 3 it will be a different number.

Part Three Inside ADB:
1. su
2. dd if=/dev/block/mmcblk0p3 of=/sdcard/efs.img
3. mke2fs /dev/block/mmcblk0p3
4. mkdir /efs
5. mount -t ext4 /dev/block/mmcblk0p3 /efs
DONT REBOOT PHONE

Part Four On Your Phone:
1. Now /efs is mounted don't unmount it
2. Do a factory reset
3. Install your Jelly Bean rom
4. It should install without any errors
5. Boot your phone
6. If everything went well it should boot.
7. After it boots your signal notification most likely will be gray and internet or calls may not work
8. To fix just install gapps and it will be fixed

There you have it if everything went correctly your efs should be working good and you should be able to go back and do your normal rom flashing.

If jelly bean boots but you don't have phone do this:
1. Go back into recovery and get adb access.
2. su
3. mke2fs /dev/block/mmcblk0p3
4. mkdir /efs
5. mount -t ext4 /dev/block/mmcblk0p3 /efs
6. dd if=/sdcard/efs.img of=/dev/block/mmcblk0p3 bs=4096

And that should fix it and you should still be able to boot jelly bean and have no efs errors.

If you have any questions feel free to post down below in the comments
The Following 7 Users Say Thank You to XylerSmith For This Useful Post: [ View ] Gift XylerSmith Ad-Free
 
 
8th September 2013, 10:42 PM |#2  
Member
Flag Mumbai
Thanks Meter: 18
 
More
Unhappy Please Help!
Got my Note2 back to life! Thanks bro

EDIT: Not exactly :\

I did get my IMEI back, but there's some problem with the factory mode and factory test apps with the stock tw rom.
I cant access the power menu nor the lockscreen.
I've tried to change the factorymode and keystr to ON in the efs/factoryapp folder, gave them the required permissions (744) and also changed the owner (1000.1000).

Still getting the two apps (factory mode and factory test) to FC on every boot and also this message if wifi is on during the boot.
the stock ROM that i've flashed is MC3.

And just to let you know, the phone works flawlessly on CM10.1 20130807 build which has LK6 baseband.
Attached Thumbnails
Click image for larger version

Name:	Screenshot_2013-09-09-16-36-38.jpg
Views:	248
Size:	33.5 KB
ID:	2246115  
The Following User Says Thank You to parthpatels007 For This Useful Post: [ View ] Gift parthpatels007 Ad-Free
2nd December 2013, 04:25 PM |#3  
Junior Member
Thanks Meter: 0
 
More
No power menu nor phone, Imei Ok
I have same behavior on my note 3. Can you tell me how got out this situation(no power menu nor phone).

Thanks

Quote:
Originally Posted by parthpatels007

Got my Note2 back to life! Thanks bro

EDIT: Not exactly :\

I did get my IMEI back, but there's some problem with the factory mode and factory test apps with the stock tw rom.
I cant access the power menu nor the lockscreen.
I've tried to change the factorymode and keystr to ON in the efs/factoryapp folder, gave them the required permissions (744) and also changed the owner (1000.1000).

Still getting the two apps (factory mode and factory test) to FC on every boot and also this message if wifi is on during the boot.
the stock ROM that i've flashed is MC3.

And just to let you know, the phone works flawlessly on CM10.1 20130807 build which has LK6 baseband.

2nd December 2013, 08:36 PM |#4  
Member
Flag Mumbai
Thanks Meter: 18
 
More
Quote:
Originally Posted by vit0r94

I have same behavior on my note 3. Can you tell me how got out this situation(no power menu nor phone).

Thanks

I gave right permissions to all the files in the efs folder (almost gave all permissions '-rwrxr' ), and rebooted, and that's it!
16th December 2013, 05:19 AM |#5  
android addicts's Avatar
Senior Member
Thanks Meter: 96
 
More
Quote:
Originally Posted by parthpatels007

I gave right permissions to all the files in the efs folder (almost gave all permissions '-rwrxr' ), and rebooted, and that's it!

Wow you are a good. It fix my issue. However if I have a correct efs backup, still my SGS3 i9300 not detect the IMEI. Don't know what is the reason.
31st December 2014, 06:12 PM |#6  
Senior Member
Flag Suceava / Iasi
Thanks Meter: 49
 
More
Can't get it to work on my phone galaxy s2 i9100, i tried a number of times, doesn't matter what i do, i get a boot loop, tried 4 different roms , stock 4.1.2, custom 4.1.2, 4.4.2 and 5.0.2, i get the same result

worked, at the end, thanks
17th September 2015, 11:51 PM |#7  
Junior Member
Thanks Meter: 0
 
More
THANK YOU!
Quote:
Originally Posted by XylerSmith

After I flashed a couple roms I couldn't boot jelly bean anymore and I noticed the error in recovery: E:\ Cant Mount /efs, when installing. But I could still boot ICS but not jellybean. I still had my IMEI and could make calls but could not boot jelly bean because it couldn't mount.

How does this issue happen?
Sometimes when installing a rom something goes wrong and it changes the partition type of /efs making it unable to be mounted. The partition is usually from ext4 to swap.

Most likely this will work on your phone but if it doesn't and your phone stops working I am not responsible.

If your like me and you couldn't get jelly bean to work then flash your device back to ics and it should boot. Once your booted inside of ics we can start the process.

Pre-Setup:
1. Be rooted and have a custom recovery installed.
2. Be on Ics and it boots.
3. Your need to have a Jelly Bean rom like Cyanogenmod on your sdcard.
4. Have adb installed on your pc and usb debugging on in your phone/tab.

Now that that's done its time to start.
Part One:
1. Boot into recovery.
2. We need to find the efs block location.
3. Go to mounts and select efs
4. It should say unable to mount
5. Go to advance and make a recovery.log
6. Put that file on your computer and open it.
7. Look through the file and you should fine something like this around the beginning of the file:
E:Unable to mount '/efs'
I:Actual block device: '/dev/block/mmcblk0p3', current file system: 'swap'
My location is /dev/block/mmcblk0p3 But yours could be different! Most likely the difference will be instead of it ending with a 3 it will be a different number. I will be saying /dev/block/mmcblk0p3 if yours is different just change it to your location.

*WARNING* Sometimes when you copy paste into adb it will auto run the command without you pressing enter. If your location is different then mine and you copy past and it auto runs it could be BAD so to be careful if you want to copy past. Copy the command paste it into Google make the change and copy that and paste into adb

Part Two:
1. When your inside recovery connect your phone to your computer and get into a adb shell. (Sometimes it will take awhile for adb to recognize your device so be patient.)
2. Once you have adb access its time to start entering the commands.(Again my location may be different the yours! Most likely the difference will be instead of it ending with a 3 it will be a different number.

Part Three Inside ADB:
1. su
2. dd if=/dev/block/mmcblk0p3 of=/sdcard/efs.img
3. mke2fs /dev/block/mmcblk0p3
4. mkdir /efs
5. mount -t ext4 /dev/block/mmcblk0p3 /efs
DONT REBOOT PHONE

Part Four On Your Phone:
1. Now /efs is mounted don't unmount it
2. Do a factory reset
3. Install your Jelly Bean rom
4. It should install without any errors
5. Boot your phone
6. If everything went well it should boot.
7. After it boots your signal notification most likely will be gray and internet or calls may not work
8. To fix just install gapps and it will be fixed

There you have it if everything went correctly your efs should be working good and you should be able to go back and do your normal rom flashing.

If jelly bean boots but you don't have phone do this:
1. Go back into recovery and get adb access.
2. su
3. mke2fs /dev/block/mmcblk0p3
4. mkdir /efs
5. mount -t ext4 /dev/block/mmcblk0p3 /efs
6. dd if=/sdcard/efs.img of=/dev/block/mmcblk0p3 bs=4096

And that should fix it and you should still be able to boot jelly bean and have no efs errors.

If you have any questions feel free to post down below in the comments

Thanks so much!! This helped me out tons!
Post Reply Subscribe to Thread

Guest Quick Reply (no urls or BBcode)
Message:
Previous Thread Next Thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes