Database Users

[Q] Help! Kernel Stopped Nexus 7 from booting!

My Nexus 7 is at Android 4.2.1 and after installing the Elite Kernel to make it boot faster with CLockWork Mod, its stuck at the X animation. I can still access fastboot mode and clockwork recovery mod but I still can start the device. Please help

reflash your rom in your cwm recovery.

Tried
simms22 said:
reflash your rom in your cwm recovery.
Click to expand...
Click to collapse
I just tried doing that and it said it was succesfully installed but I need to reboot. After tapping reboot system my Nexus 7 is still stuck in that X animation and wont boot.

1100G19 said:
I just tried doing that and it said it was succesfully installed but I need to reboot. After tapping reboot system my Nexus 7 is still stuck in that X animation and wont boot.
Click to expand...
Click to collapse
go into the bootloader/fastboot and try booring from there. you also might need to wipe data/factory reset then reflash your rom. also, sometimes force rebooting from a bootloop will boot it(long press the power button while in the bootloop, hold the power button for 10-20 seconds).

I had this happen to me yesterday when trying to flash a custom kernel to use with CM 10.1. The way I was able to fix it, was to pull the boot.img from the ROM zip and flash it through fastboot in the bootloader. The short and simple way is this:
Open the command prompt or terminal in the folder where fastboot is on your computer, extract the boot.img from the zip file of the ROM your using and place it in the folder with fastboot, then on your Nexus 7, hold in power + volume up + volume down to turn it off. Then hold down volume down and press power to boot into the bootloader. Once there, type in the command prompt/terminal: fastboot flash boot boot.img then reboot and you should be good to go.

Can I just remove the ROM?
simms22 said:
go into the bootloader/fastboot and try booring from there. you also might need to wipe data/factory reset then reflash your rom. also, sometimes force rebooting from a bootloop will boot it(long press the power button while in the bootloop, hold the power button for 10-20 seconds).
Click to expand...
Click to collapse
So if I back up the devices files with CWM and factory reseting it will remove the backup, so is there a way to send the backup onto my laptop?
Also is it possible to just remove the rom because I feel like my life would be easier if I unintalled it.
Thank You!

Hmmmmmm
Hanger84 said:
I had this happen to me yesterday when trying to flash a custom kernel to use with CM 10.1. The way I was able to fix it, was to pull the boot.img from the ROM zip and flash it through fastboot in the bootloader. The short and simple way is this:
Open the command prompt or terminal in the folder where fastboot is on your computer, extract the boot.img from the zip file of the ROM your using and place it in the folder with fastboot, then on your Nexus 7, hold in power + volume up + volume down to turn it off. Then hold down volume down and press power to boot into the bootloader. Once there, type in the command prompt/terminal: fastboot flash boot boot.img then reboot and you should be good to go.
Click to expand...
Click to collapse
Its a bit complicated. Also how do I get the boot.img to my computer from my nexus 7 because when I connected the Nexus 7 folder is not under "My Computer"
Thank you

Sounds like you need to go to fastboot and flash 4.13 bootloader.
Sent from my Nexus 7 using xda premium

Dont know
rebel1699 said:
Sounds like you need to go to fastboot and flash 4.13 bootloader.
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
How do I flash 4.13 bootloader?

All you have to do is download the same ROM on your computer that you have on your phone. If its stock 4.2.1, then download the factory image of it and extract the boot image from the zip file and follow the same steps I outlined, though instead of using: fastboot flash boot boot.img, it would be fast boot flash boot <name of boot image>.img
If you still have trouble, feel free to message me here or on GTalk and I'll walk you through it.
Sent from my Nexus 7 using Tapatalk HD

There's an important lesson to be learned here, and you unfortunately learned it the hard way. Never, ever, blindly flash something. You need to read the OP as well as catch up on at least the last page or two of the thread. Had you done so, you would have noted that Clemsyn's Elite kernels are not compatible with 4.2.1.
I'm not saying this to be a condescending, but rather to save you the possibility of getting into situations like this again. Fortunately, Nexus devices are easily recoverable from various user errors.

Accidentally erased my OS. Need help getting it back.

Made a silly mistake. I was going to flash M-kernel to my device after updating to 4.2.2 and while I was in Team Win recovery I chose to wipe cache and system. I flashed the kernel and now when I select to reboot it says "No OS installed! Are you sure you wish to reboot?" I still have the file to flash 4.2.2 but don't know how I can get it on the device in it's current state. Any help would be greatly appreciated.
I tried this method here: http://forum.xda-developers.com/showthread.php?t=1667929 however I can't get Unmount/sdcard to work in the recovery menu and therefore can't push the OS file using the cmd prompt.

You may have to fastboot the system.img and boot.img into place. How did you root? Did you use root and unlock? Did you use wugs? Do you have android sdk and fastboot installed?
Btw, I did this too. I was preparing to flash a rom, did a factory reset, wipe system, and (understand I had just gotten this device at the time LOL) wiped internal storage. Which meant my backups and update.zips were gone. The nexus 7 doesn't seem to have a way to mount twrp from recovery to side load files so I just used fastboot to fix it.

hlxanthus said:
You may have to fastboot the system.img and boot.img into place. How did you root? Did you use root and unlock? Did you use wugs? Do you have android sdk and fastboot installed?
Btw, I did this too. I was preparing to flash a rom, did a factory reset, wipe system, and (understand I had just gotten this device at the time LOL) wiped internal storage. Which meant my backups and update.zips were gone. The nexus 7 doesn't seem to have a way to mount twrp from recovery to side load files so I just used fastboot to fix it.
Click to expand...
Click to collapse
I use Root Tool Kit to root and unlock. I have android sdk installed on the PC but not sure what fasboot is. Can you explain how to "fasboot the system.img and boot.img into place"?

If you are using the toolkit, just select your device, select flash stock firmware and connect your nexus in bootloader mode (fastboot mode, hold volume down and power when it's turned off)
Sent from my Nexus 7 running Android 4.2.2

mihahn said:
If you are using the toolkit, just select your device, select flash stock firmware and connect your nexus in bootloader mode (fastboot mode, hold volume down and power when it's turned off)
Sent from my Nexus 7 running Android 4.2.2
Click to expand...
Click to collapse
Will doing this cause me to lose everything I have on the Nexus already?

How to Root without flashing custom recovery

HOW TO ROOT YOUR DEVICE WITHOUT FLASHING RECOVERY
This can be done with two methods.
ADB or FASTBOOT.
I have tested both methods and they worked for me.
I tested this on JSS15J. I am not sure about any other versions but I guess it should work.
SOME BASIC INFORMATION
Usually when you want to root your device, you must have UNLOCKED BOOTLOADER.
A CUSTOM RECOVERY is usually used to flash SuperSU to gain root access.
CUSTOM RECOVERIES ARE USUALLY FLASHED (they permanently replace your stock recovery)
In this guide, You BOOT into custom recovery by going into BOOTLOADER and then using fastboot/adb tools to flash SuperSU .
Booting is temporary and thus once you restart from recovery, the custom recovery will be gone
Make sure, you have USB debugging mode enabled. To go into bootloader you can either use adb commands ( Type [adb reboot bootloader] in cmd in platform tools directory with your device connected) or do it manually by turning it off and then holding power and volume down.
You must also have platform tools of SDK (Fastboot and ADB) for this to work. MAKE SURE YOU OPEN CMD into the folder where platform tools are present.
Try it on OWN risk. I will not be responsible for bricked devices or any damage.
ADB METHOD
Connect to your PC and make sure USB debugging is on.
COMMANDS IN BRACKETS. DON'T WRITE THEM. COMMAND WOULD BE LIKE : fastboot boot recovery.img
MAKE SURE YOUR DEVICE HAS UNLOCKED BOOTLOADER
(fastboot boot [recovery.img])--------------------- Name of recovery to be here
Mount /system and push the necessary files once the recovery has started:
(adb push su /system/xbin)
(adb push Superuser.apk /system/app)
Set correct permissions:
(adb shell)------------------------------ You have got into your device's shell
(chmod 06755 /system/xbin/su)
(chmod 0644 /system/app/SuperSU.apk)
(exit)
Reboot:
(adb reboot)
FASTBOOT METHOD
This is relatively easier as you will boot into custom recovery temporarily and then flash ZIP of SuperSU. Afterwards I recommend to clear davik cache and restart.
UNLOCKED BOOTLOADER REQUIRED
Boot into bootloader.
Type these commands to boot into custom recovery. This will not flash recovery and you will have stock recovery once you restart.
fastboot boot recovery recovery.img where recovery.img will be the file name of recovery
(After 4.4, use this command "fastboot boot recovery.img" instead of above mentioned)
After booting into reccovery, flash SuperSU and you are done.
I recommend clearing dalvik cache before leaving and restart.
And you are done.
YOU CAN ALSO USE A PREROOTED KERNEL WHICH YOU CAN FLASH VIA FASTBOOT. I AM NOT SURE IF THERE IS ANY
For information on how to retain root after OTA, please refer to this :
Update Super SU is also taken from this guide.
http://forum.xda-developers.com/showthread.php?t=2415497
For Recovery/SuperSU/TWRP
http://forum.xda-developers.com/showthread.php?t=2382051
CWM
http://forum.xda-developers.com/showthread.php?t=2381544
PLATFORM TOOLS:
http://www.androidfilehost.com/?fid=9390355257214632011
If you are stuck in a bootloop, make sure you have cleared dalvik cache in custom recovery.
I got bootloop when i tried with fastboot method as I was new to twrp, I explored it a bit and tried to remove system and tried overwriting data to see how it is different from CWM and check its strength. I got an error clearing cache so I rebooted into custom recovery to clear dalvik and my nexus booted fine (DON'T TRY THIS, JUST CLEAR CACHE AND WIPE DATA and restart)
REMEMBER, UNLOCKING BOOTLOADER WILL DELETE ALL YOUR DATA AND DOING WIPES WILL ALSO DELETE ALL YOUR DATA.
DALVIK WON'T DELETE YOUR DATA BUT
MAKE SURE YOU HAVE MADE A BACKUP using BACKUP PRO (non rooted) or Helium (non rooted) and Titanium Backup Pro (Daah, you are not rooted so this won't work)
GOOD LUCK

Booting into custom recovery to install root works fine.
As you mentioned unlocking bootloader is still a prerequisite.
You may want to just use the SuperSU install zip though. Though I haven't tried Superuser on this tablet, it is my understanding it hasn't been modified to work with 4.3 security. That may have changed since I last looked so if you find differently please post. SuperSU added a daemon mode to deal with 4.3 security changes.

sfhub said:
Booting into custom recovery to install root works fine.
As you mentioned unlocking bootloader is still a prerequisite.
You may want to just use the SuperSU install zip though. Though I haven't tried Superuser on this tablet, it is my understanding it hasn't been modified to work with 4.3 security. That may have changed since I last looked so if you find differently please post. SuperSU added a daemon mode to deal with 4.3 security changes.
Click to expand...
Click to collapse
I got bootloop but then realised it might due to trying to wipe system in twrp. Clearing dalvik worked fine .SuperSU used

So you don't replace stock recovery if you boot into a custom recovery using fastboot?
Sent from my Nexus 7 (2013)

Muikkuman said:
So you don't replace stock recovery if you boot into a custom recovery using fastboot?
Sent from my Nexus 7 (2013)
Click to expand...
Click to collapse
The trick here is to BOOT into custom recovery BUT not FLASH recovery permanently. Once you restart, the CUSTOM recovery will be gone.
You can use simple commands if using Fastboot
fastboot boot recovery [recovery name.img]
This way you will install SuperSU using recovery which is relatively easier than ADB commands.
You will only go into recovery temporarily.
I also read a forum where you can preserver root even after OTA/ Updates.
[UPDATE]
http://forum.xda-developers.com/showthread.php?t=2415497
Do check that out as well.
I tried this with Twrp and superSU.
I got bootloop as I have been always CWM person so I accidently tried to delete system too with dalvik cache and hard reset and I got an error
However, I boot again into recovery and cleared wipes and the bootloop was gone

Hnk1 said:
The trick here is to BOOT into custom recovery BUT not FLASH recovery permanently. Once you restart, the CUSTOM recovery will be gone.
You can use simple commands if using Fastboot
fastboot boot recovery [recovery name.img]
This way you will install SuperSU using recovery which is relatively easier than ADB commands.
This way you will only go into recovery temporarily.
I also read a forum where you can preserver root even after OTA/ Updates.
Do check that out as well.
I tried this with Twrp and superSU.
I got bootloop as I have been always CWM person so I accidently tried to delete system too with dalvik cache and hard reset and I got an error
However, I boot again into recovery and cleared wipes and the bootloop was gone
Click to expand...
Click to collapse
Thanks for your reply I'll make sure to check everything out.
Sent from my Nexus 7 (2013)

Muikkuman said:
Thanks for your reply I'll make sure to check everything out.
Sent from my Nexus 7 (2013)
Click to expand...
Click to collapse
Anytime mate

How do we clear dalvik without a custom recovery?

Master619 said:
How do we clear dalvik without a custom recovery?
Click to expand...
Click to collapse
You restart your device. Boot into bootloader and use fastboot to Boot into custom recovery(command given in post above).Once Into recovery, you can easily clear dalvik cache.
And remember, it might not require clearing cache because I was exploring twrp n overwriting data n tried To delete system to see how powerful the recovery is. I will update guide now

muikkuman said:
so you don't replace stock recovery if you boot into a custom recovery using fastboot?
Sent from my nexus 7 (2013)
Click to expand...
Click to collapse
master619 said:
how do we clear dalvik without a custom recovery?
Click to expand...
Click to collapse
guide updated. Check it.
Platform tools are being attached

The "fastboot boot recovery recovery.img" command is not working anymore. The command prompt returns with a "cannot load recovery" error. At least that's what it does on my Nexus 7 running Android 4.4.2.
This seems to affect Android 4.3 and upwards according to this Nexus 4 thread: http://forum.xda-developers.com/nexus-4/help/solved-fastboot-boot-recovery-img-t2380675
There's a workaround with a different fastboot command line as mentioned in the thread. I wonder if there's also a fix for the Nexus 7. Any replies would be greatly appreciated.

gunner49 said:
The "fastboot boot recovery recovery.img" command is not working anymore. The command prompt returns with a "cannot load recovery" error. At least that's what it does on my Nexus 7 running Android 4.4.2.
This seems to affect Android 4.3 and upwards according to this Nexus 4 thread: http://forum.xda-developers.com/nexus-4/help/solved-fastboot-boot-recovery-img-t2380675
There's a workaround with a different fastboot command line as mentioned in the thread. I wonder if there's also a fix for the Nexus 7. Any replies would be greatly appreciated.
Click to expand...
Click to collapse
Did you try: fastboot boot recovery.img ?

mdamaged said:
Did you try: fastboot boot recovery.img ?
Click to expand...
Click to collapse
That worked a treat! Thanks a lot mate!

Those who finding difficulty in rooting Nexus 7 (2013) can use Wugfresh Nexus Root Toolkit. It is so powerful that you would find every function you would like to do on your Nexus 7, from the comfort of your PC. Also watch qbking77 's video on using the Toolkit for further information.

[Q] Boot Loop (CM Recovery)

First of all, I know that there are many people asking same thing. I have checked those threads and I guess I am just a little bit more clueless. Last time I was able to use my Nexus 10 was 3 months ago. Since then I tried to solve it many times, but no luck so far. I will try to explain some of the issues I'm experiencing, but I'm afraid I'm not too good with all the expressions people are using on this forum.
1. ADB vs Fastboot
I see this mentioned often and I don't know what exactly it means. It's amazing to me that I can't google it, I'm usually good with googling. I can see that my N10 is sometimes listed under ADB and sometimes under Fastboot devices but I have no idea what I did to change that. I do know that whatever I try to do at certain point, it's always in "wrong" mode, waiting for adb etc. So if someone can point me to a thorough explanation, a wiki or something, that would be very nice.
2. The Loop
I managed to get ClockworkMod v6.0.4.3 installed and it's this loop that device is now inside. I've tried pretty much all possible combinations, wiped both caches, did factory reset, rebooted to system/bootloader/recovery... nothing. Always ends up on same CM menu.
3. Android Toolkit
I have installed this on my computer and tried so many things that I forgot about all details. I tried flashing the big 400 MB stock image to the device, but haven't been successful (says waiting for ADB, even if the device WAS listed as ADB device before I started the procedure). I am also expecting to see the N10 as another "drive" from my desktop, if you know what I mean, so that I could copy files to it. However I don't see it that way, I only see it registered as a Nexus 10 device, like a mouse or any other non-drive device. Is this normal?
So what to do? Can anyone tell me in a simple way, because I am obviously stupid enough to find threads I've seen so far not clear enough. And I would actually think that my computer literacy level is rather high, I think that this Nexus 10 is the only thing that brought me to my knees in last 20 years of working with computers.
And when I say "simple wiki style" I'm thinking of something like this:
Ok. no links allowed, great. It's a redmondpie article named
/how-to-set-up-android-adb-and-fastboot-on-windows-tutorial/
This is easy enough for me... but do I assume correctly that all this has already been done with me installing Android Toolkit? If so, it uses a different path structure and I don't see all those folders...

So u do have cmw installed, when u try to flash a ROM it just boots to recovery?
Sent from my Nexus 10 using Tapatalk

newellj79 said:
So u do have cmw installed, when u try to flash a ROM it just boots to recovery?
Click to expand...
Click to collapse
You mean flashing ROM only with CWM, not through android toolkit? Through CWM menu I have tried (many times):
- wipe data / factory reset
- wipe cache partition
- wipe dalwik cache
I don't see way to do anything with:
- install zip
- backup and restore
- mounts and storage
Rebooting menu items do following:
- Reboot system --> reboots to same CWM recovery menu
- Reboot to bootloader --> reboots to the stock bootloader "menu" where I can choose between Start, Power Off, Recovery mode (picking this will reboot to CWM recovery menu) and Restart bootloader (picking this will reboot to this same menu)
- Reboot recovery --> reboots to same CWM recovery menu

1 adb works only in os and recovery, fastboot works only in bootloader
2 it looks like your recovery is screwed up, flash this with fastboot
http://techerrata.com/file/twrp2/manta/openrecovery-twrp-2.6.3.1-manta.img
fastboot erase recovery
fastboot flash recovery nameofrecovery.img
3try not to use toolkits, you have a nexus, toolkits are more complicated than manual methods and you won't learn anything from it
Once you have recovery
Wipe all, then you will will need to use adb sideload to flash ROM as you have no ROM on emulated sdcard
Go to advanced menu
adb sideload
adb sideload nameofROM.zip
adb sideload gapps.zip
For more info on fastboot
http://forum.xda-developers.com/showthread.php?t=2277112
Sent from my Nexus 7 using XDA Premium 4 mobile app

demkantor said:
1 adb works only in os and recovery, fastboot works only in bootloader
2 it looks like your recovery is screwed up, flash this with fastboot
http://techerrata.com/file/twrp2/manta/openrecovery-twrp-2.6.3.1-manta.img
fastboot erase recovery
fastboot flash recovery nameofrecovery.img
3try not to use toolkits, you have a nexus, toolkits are more complicated than manual methods and you won't learn anything from it
Once you have recovery
Wipe all, then you will will need to use adb sideload to flash ROM as you have no ROM on emulated sdcard
Go to advanced menu
adb sideload
adb sideload nameofROM.zip
adb sideload gapps.zip
For more info on fastboot
http://forum.xda-developers.com/showthread.php?t=2277112
Sent from my Nexus 7 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
The first part worked ok. The second part doesn't.
ADB sideload - I went there in the Nexus menu
adb sideload kitkat2501.zip
returns this:
* failed to write data 'protocol fault (no status)' *
If I do it without starting adb sideload on nexus, then it just says "error: closed", so it does recognize the change.
I downloaded the latest sdk tool, 64-bit, and the stock nexus 10 rom from 25th Janaury.

Let's do this, grab the latest stock for manta from here
https://developers.google.com/android/nexus/images
fastboot erase system -w
fastboot erase boot
fastboot erase recovery
And extract and run the flashall.bat
This should bring you to the latest official software/firmware. Then with you up and running we can root and give you custom recovery,ROM,whatever
If you have an issues at all please copy and paste all input/output from cmd/terminal here
Sent from my Nexus 7 using XDA Premium 4 mobile app

demkantor said:
Let's do this, grab the latest stock for manta from here
fastboot erase system -w
fastboot erase boot
fastboot erase recovery
And extract and run the flashall.bat
This should bring you to the latest official software/firmware. Then with you up and running we can root and give you custom recovery,ROM,whatever
If you have an issues at all please copy and paste all input/output from cmd/terminal here
Sent from my Nexus 7 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
You are a wizard. I got it all ok now and I added CWM to it, it was easy to root it from there.

Stock recovery flashable .zip?

How can i flash the stock recovery?
Or what can i do to have it? I want to download the new firmware...but im using the TWRP Recovery... (Bootloader unlock)
Any suggestions?

andrexp31 said:
How can i flash the stock recovery?
Or what can i do to have it? I want to download the new firmware...but im using the TWRP Recovery... (Bootloader unlock)
Any suggestions?
Click to expand...
Click to collapse
k1ll3r8e's toolkit should be able to do it for you, give it a try.

Thanks for the answer. But the stock recovery didnt work for the thing that i want to do... I want a fresh installation of the last compilation of the firmware. I want to wipe it all...and install the the stock firmware,to start from 0. (Cause i have to much garbage in the system. The Ram memory is down of 1,60 gb with 3 user apps installed) You know how can i do that?
I had it the stock recovery this morning but didnt download me the last firmware...(cause i have the bootloader unlocked) So i return to twrp...
I just want a fresh installation of the stock rom to start from there.

andrexp31 said:
How can i flash the stock recovery?
Or what can i do to have it? I want to download the new firmware...but im using the TWRP Recovery... (Bootloader unlock)
Any suggestions?
Click to expand...
Click to collapse
You can get stock recovery here http://forum.xda-developers.com/huawei-p9lite/how-to/root-root-recovery-bootloader-unlock-t3457564
Download the zip extract it and I believe it's called stock.img
I'm going to assume bootloader is unlocked and USB debugging is enabled
Enter fastboot mode and connect to PC
Load up adb terminal on your PC type fastboot flash recovery PATH/stock.img (PATH= file path to the recover img)
After that is done download the latest firmware for your phone version and extract it, extract update.zip and put its contents on the root of your sd card in a file called dload (make if it doesn't exist)
With the SD card inserted and phone turned off power up by holding volume up, volume down and power at the same time for about 8 seconds, this will start the update, once that has done you will want to power the device holding volume up and power for a while, select factory/data reset, then wipe cache, reboot into clean stock rom.
This will also remove root and relock bootloader