Reverting back to stock ROM - Galaxy S II Q&A, Help & Troubleshooting

I put a custom ROM on my GS2 for the first time, it involved updating a kernel.
However I really don't like the custom rom I installed and now I want to go back to the stock ROM but with the samsung stuff froze/removed.
Could anyone tell me how to do this please? I'm not sure where to download the stock ROM's from and I'm not sure if I need to change the kernels again.
Cheers

I suppose you just need to d'load a stock ROM and flash it via odin with the phone in download mode.
Very simple.

Stock rom post Dev section .
Remove Samsung bloatware script should be in the same section .
jje

If you made a nandroid backup you can just restore it completely and everything should be back to the way it was.
Sent from my GT-I9100

Related

how to back up stock rom

hi everyone, i plan to root and install custom ROM for SGS II. I don;t want to use ROM uploaded by other people for some selfish insecure reason (feel safer to use my own stock ROM)
So, before that, how do i backup everything in the phone including the stock rom? because we need to changed back the phone to default state to claim the warranty.
You download the stock rom to match yours now and flash that if you ever need to claim warranty.
Plus use the USB recovery jig to reset custom rom counter to zero before any warranty .
jje
leeyming said:
hi everyone, i plan to root and install custom ROM for SGS II. I don;t want to use ROM uploaded by other people for some selfish insecure reason (feel safer to use my own stock ROM)
So, before that, how do i backup everything in the phone including the stock rom? because we need to changed back the phone to default state to claim the warranty.
Click to expand...
Click to collapse
There is no way to save your stock firmware without rooting it before.
The way to save it is to install the Kernel CF-ROOT matching your firmware version and to use CWM Recovery to do a nandroid backup ( rom + data + cache).
You will find safe to use stock firmwares in the officizl thread in the dev section.
Sent from my GT-I9100 using XDA Premium App
everyone thanks for the answer. I just want to have confirmation before i proceeed with rooting.
i don't want to download because of the reason i stated above.

[Q] Kernel

Is it ok to flash a custom kernel on top of another custom kernel?
Sent from my GT-I9100 using xda premium
You dont need to revert on the original one before flash another custom. But you need to format dalvik cache and cache in recovery before flashing or you probably have a bootloop.
I suggest to make a backup of the rom in recovery, so If something goes wrong you can enter recovery and have the latest known working rom back in 2 minutes.
Please note flashing kernels always have a very small chance to corrupt your efs partition, its suggested to backup your efs folder before start play with roms and kernels. How to backup the efs, use the search tool of the forum
Sent from my GT-I9100 using Tapatalk
rembrandtlnx said:
You dont need to revert on the original one before flash another custom. But you need to format dalvik cache and cache in recovery before flashing or you probably have a bootloop.
I suggest to make a backup of the rom in recovery, so If something goes wrong you can enter recovery and have the latest known working rom back in 2 minutes.
Please note flashing kernels always have a very small chance to corrupt your efs partition, its suggested to backup your efs folder before start play with roms and kernels. How to backup the efs, use the search tool of the forum
Sent from my GT-I9100 using Tapatalk
Click to expand...
Click to collapse
Thanks for that. I know how to backup efs. Can i just use nitrality instead of ADB? To flash ROMs does it need to be in a specific firmware like sgsl or is it ok to have different firmware from the base of a custom rom?
Sent from my GT-I9100 using xda premium
I know my english sux sry:
Depends on the kernel but usually it is listed in the kernel thread the how to (odin or clockworkmod), clockworkmode is already on your phone if you rooted it with cf-root.
Now, to enter clockworkmod recovery, just push volume up + home + power button until the S2 bootlogo appears, then wait few seconds.
About the kernel type, i always flashed any kernel despite of my baseband, the difference is not so big.
if something is not working, you can always youse the nandroid backup (the backup done with the recovery cwm (up+home+power) and get back to the previous rom with previous kernel.
Im not really in the kernel "how to" someone else can prolly give you more detailed info, but as for me, i flashed ninphetamine 2.05 and 2.1.3 in cwm and it worked.
But.. as always, the kernel developers got a how to install in their kernel thread, so just read those and be sure about if you need odin or clockworkmod, if you are not sure, DONT flash anything until you are sure on how to proceed or wich system to use for flashing, better keep an old kernel with a working phone than have a brick to hold the papers
PS: also almost all the roms on the S2 forum are flashable with the clockworkmod, only few (like the lite'ning) are flashable with odin.
Again, i know im boring, dont proceed if you are not sure, better ask 10 times instead brick your phone
ephraim033 said:
Is it ok to flash a custom kernel on top of another custom kernel?
Yes not a problem flash as per the custom kernel instructions .
Kernel can be changed within an individual firmware or custom rom .
jje
Click to expand...
Click to collapse
Thanks for the reply guys. Coming back to my second question. What if i have KF1 and the rom i want to flash has a base of KI3, should i flash to stock KI3 first before flashing the custom rom or is it ok to flash a KI3 custom rom without flashing first to stock KI3?
Sent from my GT-I9100 using xda premium
The custom rom first, the kernel after.
I got the habbit to boot succesfully at least once the custom rom. If everything is ok i then flash the kernel. Better do 1 task at time.
You can decide to try the rom without change the kernel..and try a different one if you experience battery drain or other problems.
Sent from my GT-I9100 using Tapatalk
If i am on KH3 and want to flash a custom rom based on KI4 then i would flash stock KI4 and KI4 root first .
Custom rom flashed i will often try a different kernel later .
jje
from my experience
I have found that when i upgraded rom from gingerbread to ics that most custom kernals work with these roms ie now running with xxlpw ics (from gingerbread) with xwlp7 kernal. from what i have read on other posts and threads i could swap kernal to siya or any other as the mega good developers have made them (hotswappable) interchangeable as previous reply said swapping kernal might give you better battery or solve overheat probs.
Eg iwas running darkys rom with siya kernal v?something my phone rocketed temp in short time so i swapped kernal for an up to date one (could have used older one) it solved problem.
Anyone feel free to correct explination im still learning too lol
linuxnubee said:
I have found that when i upgraded rom from gingerbread to ics that most custom kernals work with these roms ie now running with xxlpw ics (from gingerbread) with xwlp7 kernal. from what i have read on other posts and threads i could swap kernal to siya or any other as the mega good developers have made them (hotswappable) interchangeable as previous reply said swapping kernal might give you better battery or solve overheat probs.
Eg iwas running darkys rom with siya kernal v?something my phone rocketed temp in short time so i swapped kernal for an up to date one (could have used older one) it solved problem.
Anyone feel free to correct explination im still learning too lol
Click to expand...
Click to collapse
I'll just point out this thread was dead since Sept 30 before you posted...

[Q] safe current SGS ROM (original samsung) before I install e.g. CM7

hi!
I plan to root my SGS2 phone (using odin to put a CF-Kernel on it) and then I plan to install e.g. CM7...
But I want to backup as much as possible in advance to be able to return to stock as close as possible. because of this I want to backup my very on ROM (which is at the moment samsung 2.3.4 stock with TouchWiz), so that I don't have to download a stock-ROM or something like that...
1.) Is it possible to backup my current ROM (e.g. via CWM) so that I can return to this when I find out that I don't like CM7 for example? so that I won't need to download a separate stock-rom to get to my current stock-rom, because I backed my current ROM up myself?
2.) if this is possible, can I then use KIES again after I recovered my own current stock-rom after I decided to not use cm7 anymore and I want to eturn to my own stock-backup (that I backed up in advance - if it was possible (see previous question)) to then use KIES to update e.g. to icq cream sandwich when it's released next year on the "nomal" KIES-way...?
3.) according to that I have this post, where I ask, if it's possible to backup my stock-kernel before replacing it with CF-Kernel... I'd appreciate help there, too, very much!
thank you very much!!
Read what is your current rom at about section and take notes about rom and kernel.
Then go to Intratech's thread, find your firmware and original kernel,
Download and keep in a safe place.
Use Odin to flash back to stock wit the firmware you downloaded.
Cheers.
Sent from outter space using a Gremlin for delivery!
Full Backup: http://forum.xda-developers.com/showthread.php?t=1409484
However its untested by me how you put it back.
Also look at Post 9 from oinylicious in this Thread, you can use Zergrush only for temp root instead of Doomlords Tool where you get permanent root.
This works for the whole Phone, not just the Kernel
I did exactly what your planning.
I had a stock phone and firmware.
Used cfroot kernel to root.
Did a nandroid backup or CWM backup.
Did a titanium backup of apps.
Flashed CM7 nightly Rom.
All was good but wanted to go back.
Did a CWM restore.
Was back on stock all good as before.
Did the same with miui.
Actually I can go back and forth as I have CWM backups of each type.
Hope this helps.
Sent from my GT-I9100 using XDA App
aceofclubs said:
I did exactly what your planning.
I had a stock phone and firmware.
Used cfroot kernel to root.
Did a nandroid backup or CWM backup.
Did a titanium backup of apps.
Flashed CM7 nightly Rom.
All was good but wanted to go back.
Did a CWM restore.
Was back on stock all good as before.
Did the same with miui.
Actually I can go back and forth as I have CWM backups of each type.
Hope this helps.
Sent from my GT-I9100 using XDA App
Click to expand...
Click to collapse
thank you! yes, this is what I inteded to to. when this really works, it's great.
sorry for the noob question but "nandroid backup or CWM" is already included in the CF-Kernel, am I right?
the resulting question would be if it's possible to backup the original kernel... before I flash the CF-Kernel... I asked it here...
sorry for the noob question but "nandroid backup or CWM" is already included in the CF-Kernel, am I right?
If its the CWM and ROOT Kernel yes .
the resulting question would be if it's possible to backup the original kernel... before I flash the CF-Kernel... I asked it here...
No but you should find matching kernel in stock roms thread .
jje
JJEgan said:
the resulting question would be if it's possible to backup the original kernel... before I flash the CF-Kernel... I asked it here...
No but you should find matching kernel in stock roms thread .
jje
Click to expand...
Click to collapse
is it really impossible?
read my post, you obviously missed it
gänsebraten said:
read my post, you obviously missed it
Click to expand...
Click to collapse
hi gänsebraten, thank you very much for your hint. I read your linked post now. it looks very promising. and is exacly what i mentioned. but...
although, if it's still not shure if it is possible to restore the backed up files via your method... it's like playing with fire... I'm referring to your post...
did anyone tryed this way to backup and restore KERNEL and ROM and can confirm it works? I'd appreciate it very much

help flashing roms

Im new to the whole SGS2 so needed a little help ive rooted my Galaxy and its on UK 2.3.5 stock rom my question is can i flash any rom i choose or is it like when rooting it when i had to get a kernel that matched.
The other thing is, is it worth buying Odin Mobile.
Cheers
Once you root your phone and have CWM recovery and not the stock one you can flash any ROM you choose.It has nothing to do with kernels but each ROM is based on a firmware so you should match your firmware to a ROM based on the same to start with and if you choose to stay with the same ROM then there are non-wipe ROMs that can be flashed over top without worries.Just be sure you read properly the install/flash instructions.Some ROMs need Odin to be flashed but most just need to be pasted to your internal-SD and then flashed in recovery mode.Ill leave a link below to my ROM where there is an instruction guide so you can read it to see what I mean.
http://forum.xda-developers.com/showthread.php?t=1290468
polly69 said:
Im new to the whole SGS2 so needed a little help ive rooted my Galaxy and its on UK 2.3.5 stock rom my question is can i flash any rom i choose or is it like when rooting it when i had to get a kernel that matched.
The other thing is, is it worth buying Odin Mobile.
Cheers
Click to expand...
Click to collapse
It depends on how you have rooted ...... if as mentioned above you have CWM (means you have flashed a custom/insecure stock kernel) just flash a ROM with CWM Recovery like any ZIP but i'd advise you to reset the phone before that .... since you are on Stock ROM which is Odexed and all custom ROMs are deodexed you might end up in a bootloop also may i suggest CheckROM as it is simple to install and highly customizable thus i recommend this as your first flash......
checkrom thread:
http://goo.gl/eRCJt
else i use this site it's pretty awesome to keep track of things
http://goo.gl/ihgse
Cheers to both of you, i think i will give checkrom ago as theres that many to choose from and im new to the rooted SGS2.

[Q] Unbranded 2.3 UK f/w?

Sorry for being a bit dumb, I used to be on XDA all the time when I had my x10 but that's some time ago now!
I want to flash an original unbranded uk 2.3 ROM on to my phone. No tweaks, rooting etc
Can someone please help me find one or link me to the relevant thread?
And once I've got the ROM what do I need to do? With the x10 it was a simple case of place the zip on the sd, boot into xrecovery and flash. Is it the same with the GS2?
Curious as to why you'd want to put a 2.3 GB rom on your phone ? Anyhoo, have a look at this thread. If you find links don't work, note the details of the firmware you want & search Samfirmware.com for it.
Want to install unbranded GB so I can get the official ICS update via Kies. That would work - right?
Yep. If you install 'correct' stock rom for your region it should give you the correct CSC for your country & you should be able to get Kies updates. If it doesn't work, you can always grab ICS stock roms from here/elsewhere & flash them manually.
psx612 said:
Want to install unbranded GB so I can get the official ICS update via Kies. That would work - right?
Click to expand...
Click to collapse
Just a tad confused as there's so many ROMs to choose from!
I've installed Clockwork Mod, is it now just a case of find the correct ROM, stick it on the SD card and boot the phone in recovery?
Doubt you'll find many stock roms that are CWM flashable.
The majority (all ?) are Odin flashable, because people tend to go back to stock to either get a 'clean slate' they can then install custom roms/kernels over if they've had problems, or if they're sending the phone in for warranty service/replacement.
Right, so gotta work out how to use Odin....cheers!
So that means that custom ROMs can be flashed using CWM?
Sent from my GT-I9100 using xda premium
Many (most) custom roms are CWM flashable. Some also have Odin flashable versions.
That's what makes trying custom roms so easy, you backup your existing rom in CWM, flash the rom you want to try, if you don't like it you restore your backup & go back to your previous setup. All in a matter of minutes.
psx612 said:
Right, so gotta work out how to use Odin....cheers!
So that means that custom ROMs can be flashed using CWM?
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
As to the last post .
I have custom GB rom and want to try but not buy ICS custom rom .
Nandroid backup of full existing GB rom and all apps and settings via CWM recovery .
Flash ICS custom rom via CWM recovery test it make a nandroid backup also .
Boot CWM recovery and go back to the exact GB settup and i can even restore the ICS rom again .
jje

Categories

Resources