Hello dear XDA Community,
- Xperia Z Ultra
- 4.4.2
- 14.3.A.0.681
- C6833
I have a big problem with understanding all of this tutorials. I read everything about rooting and unlocking the Bootloader.
I understood that I need to backup my TA Partition for Unlocking my Bootloader so I can continue to use Sony technology.
Requirements ? Root. Okay that was my first problem. So i looked up how to root my phone and what do i need ? A phone with a unlocked bootloader. great! Sure you can say "look at this topic and carefully read" but I really did that and I am really helpless. Thanks for any help!
What did I read ?
- http://forum.xda-developers.com/showthread.php?t=2292598&nocache=1 (requires root)
- http://forum.xda-developers.com/showthread.php?t=2569904 (requires unlocked bootloader)
- watched severel youtube videos and encountered the same problem
Greets
tr0teK
When your bootloader is unlocked, you can never use X-Reality and any other item which requires the DRM in the Trim Area partition,
Restoring the TA partition without relocking the bootloader will not result in the return of X-Reality and such even if you are using a Sony ROM. This situation appears to have changed since the release of 4.4.
Backing up the TA partition is only good for relocking the bootloader on a Stock ROM (any custom AOSP, CM, AOSPA etc will fail to boot on a locked bootloader), for personal choice or returning the phone under warranty.
You can unlock the bootloader when not rooted, in fact you don't do it with the phone running normally anyway so root or not rooted, it does not matter in that sense.
You don't need to unlock the bootloader to root, if you are willing to re-set up your phone again. What you need to do is downgrade to 4.2, which is rootable, root, install recovery and flash the 681 pre-rooted zip, and use flashtool to flash the associated ftf file to get rooted on 681.
Follow the instructions in Lord Manhattan's thread that you linked to,in order to downgrade and install a recovery, then visit the following link to get the zip & ftf to re-up to 4.4 (681). You most likely will lose cellular connectivity whilst you are downgraded (there is a way around this, but as you are only going down to 4.2 to get a recovery, maintaining your IMEI for that short period of time is just a waste of effort), but it will return when you are back on 681 (4.4).
http://forum.xda-developers.com/showthread.php?t=2687848
- Downgrade to 532
- Root it using Bin4ry's tool
- Backup the TA partition
- Unlock bootloader
- Either update to 681 again and take it from there or flash a kernel with recovery/TWRP and flash a pre-rooted 681. It's easy to root 681, so whatever floats your boat.
Don't mean to hijack this topic but I don't want to open another thread,
if I back up the TA partition, unlock bootloader, root the phone, then relock bootloader, then restore TA partition to bring back the xreality,
I am not going to install custom recovery and Roms.
Thanks for the Informations. I will give it a try the next days and report you if it worked.
coolmingli said:
Don't mean to hijack this topic but I don't want to open another thread,
if I back up the TA partition, unlock bootloader, root the phone, then relock bootloader, then restore TA partition to bring back the xreality,
I am not going to install custom recovery and Roms.
Click to expand...
Click to collapse
Technically it'll work, but i have never done it before. Everything should go smoothly until you're going to re-lock the bootloader. You can't re-lock it on a custom kernel, and you'll be on a custom kernel once you flash Jackie's kernel with recovery, so you'll have to flash a complete stock kernel, then restore the TA partition with the TA Backup Tool, which will also automatically re-lock the bootloader. You should in theory end up with a complete stock ROM with root. That's on paper.
Worst case scenario? If you re-lock the bootloader while you're on a custom kernel, it'll explode it won't power on at all, and all you'll get is a blinking red LED and death. To fix this, just unlock the bootloader in Flashtool again and you're back to start again. It's not dangerous, but it's nerve wrecking to see it there, just blinking without any sign of life. I almost crapped my pants the first time i experienced it, and had no clue what was happening or what to do.
LordManhattan said:
Technically it'll work, but i have never done it before. Everything should go smoothly until you're going to re-lock the bootloader. You can't re-lock it on a custom kernel, and you'll be on a custom kernel once you flash Jackie's kernel with recovery, so you'll have to flash a complete stock kernel, then restore the TA partition with the TA Backup Tool, which will also automatically re-lock the bootloader. You should in theory end up with a complete stock ROM with root. That's on paper.
Worst case scenario? If you re-lock the bootloader while you're on a custom kernel, it'll explode it won't power on at all, and all you'll get is a blinking red LED and death. To fix this, just unlock the bootloader in Flashtool again and you're back to start again. It's not dangerous, but it's nerve wrecking to see it there, just blinking without any sign of life. I almost crapped my pants the first time i experienced it, and had no clue what was happening or what to do.
Click to expand...
Click to collapse
Thanks for the reply, I think I will ditch rooting from this phone, too much troubles, I don't understand why Sony put the DRM key in a trim partition, perhaps they don't want us to root the phone after all.
I did it guys. It worked!
My steps:
- Downgraded to 4.2.2 with Flashtool (.532)
- Rooted with Bin4ry's tool
- Installed CWM and TWRP Dual Recovery for Xperia Z locked Bootloader by krabappe12548
- Flashed to 4.4.2[rooted] (http://forum.xda-developers.com/showthread.php?t=2687848)
Now I have the newest version with Root Access. Everything works great
Greets
tr0teK
tr0teK said:
I did it guys. It worked!
My steps:
- Downgraded to 4.2.2 with Flashtool (.532)
- Rooted with Bin4ry's tool
- Installed CWM and TWRP Dual Recovery for Xperia Z locked Bootloader by krabappe12548
- Flashed to 4.4.2[rooted] (http://forum.xda-developers.com/showthread.php?t=2687848)
Now I have the newest version with Root Access. Everything works great
Greets
tr0teK
Click to expand...
Click to collapse
is this witout unlock the bootloader?
MjsNL said:
is this witout unlock the bootloader?
Click to expand...
Click to collapse
Yep, that will work well on a locked BL
If you are only downgrading to flash the current rooted firmware, you don't even need to root 532, as [nut]'s dual recovery can be installed by the same method that bin4ry's root is delivered, just install the recovery, flash the zip, flash the ftf and away you go
Related
I have a new xperia z ultra c6806
Read a lot but still confused. ( Not everybody is made equal )
I want to root and back up TA
1 - My understanding is for backing up TA, i need to be rooted. But for rooting I need to be unlocked. But unlocking will erase the TA information. Am I wrong.
2- If I unlock boatloader can I flash back to pure stock for either warranty or returning the device.
Thanks
C6806 eh?
- Open the dialer and dial *#*#7378423#*#*
- Go to Service Info -> Configuration and check what is says under "Rooting status". Does it say Yes or No?
If it says yes, go ahead and downgrade to 532 and root it using Bin4ry's root tool, backup your TA partition and then unlock the bootloader, update to 757 again and flash Jackie's kernel and flash SuperSU. You can find links and what not here.
LordManhattan said:
C6806 eh?
- Open the dialer and dial *#*#7378423#*#*
- Go to Service Info -> Configuration and check what is says under "Rooting status". Does it say Yes or No?
If it says yes, go ahead and downgrade to 532 and root it using Bin4ry's root tool, backup your TA partition and then unlock the bootloader, update to 757 again and flash Jackie's kernel and flash SuperSU. You can find links and what not here.
Click to expand...
Click to collapse
Thanks for the reply
It says " Bootloader unlock allowed: Yes
So I guess, I will follow what you are saying
One thing; don't panic when you're noticing that you're not getting any signal at all (cell, WiFi etc.). That's the way it is when you're downgrading the baseband past .290, but you're only going to be on 532 for a short period of time, so it's no big deal. You'll get your signal back once you're back on 757.
LordManhattan said:
One thing; don't panic when you're noticing that you're not getting any signal at all (cell, WiFi etc.). That's the way it is when you're downgrading the baseband past .290, but you're only going to be on 532 for a short period of time, so it's no big deal. You'll get your signal back once you're back on 757.
Click to expand...
Click to collapse
Got 532 installed and unlocked but now cant update to 757.... Pc companion is saying I am uptodate..
There seems to be no link to download 6806 757 firmware
Edit : oofff ... finally got everything working.. That was lot of work...
aalupatti said:
Got 532 installed and unlocked but now cant update to 757.... Pc companion is saying I am uptodate..
There seems to be no link to download 6806 757 firmware
Edit : oofff ... finally got everything working.. That was lot of work...
Click to expand...
Click to collapse
So you figured out that you had to use Flashtool? You backed up TA? And you managed to unlock the bootloader and root?
Don't worry, this is a one time thing. The boring stuff is the downgrading and backup of TA, so since you've backed it up, it's done. If you have to relock your bootloader and un-root for whatever reason and you want to root again, you don't have to do this again. You then have to unlock the bootloader and simply flash a kernel.
Sent from my C6833
LordManhattan said:
So you figured out that you had to use Flashtool? You backed up TA? And you managed to unlock the bootloader and root?
Don't worry, this is a one time thing. The boring stuff is the downgrading and backup of TA, so since you've backed it up, it's done. If you have to relock your bootloader and un-root for whatever reason and you want to root again, you don't have to do this again. You then have to unlock the bootloader and simply flash a kernel.
Sent from my C6833
Click to expand...
Click to collapse
My issue was downgrading and some driver issues with windows 8. All went well..
However now when I reboot I get this error " System UID's are inconsistent, you need to wipe your data partition or your device will be unstable"
But fixed that using twrp
I cant believe how good quality the phone hardware is.. Was using samsung for the last few years...
I am waiting for the next generation of z ultra and going to get that too.... Wish they introduce qi charging...
I will soon be getting a new Z Ultra and I would like to know what to do:
I want to stay on the stock rom but root it and update it to the latest version
So should I downgrade/root/unlock bootloader/whatever before i start using it?
If so, can someone tell me the steps to doing it e.g.
1) downgrade to .623
2) unlock bootloader
3) flash kernel and recovery
4) backup TA
5) update to latest version
6) root
???
panyan said:
I will soon be getting a new Z Ultra and I would like to know what to do:
I want to stay on the stock rom but root it and update it to the latest version
So should I downgrade/root/unlock bootloader/whatever before i start using it?
If so, can someone tell me the steps to doing it e.g.
1) downgrade to .623
2) unlock bootloader
3) flash kernel and recovery
4) backup TA
5) update to latest version
6) root
???
Click to expand...
Click to collapse
If all you are wanting is latest firmware with root just let it update then follow this thread.
http://forum.xda-developers.com/showthread.php?t=2784900
If you do decide to unlock bootloader then you have listed steps in wrong order.
1. Root
2. Backup TA
3. Unlock Bootloader
Alternately you could use the dualrecovery installer for step 1 as it has the root exploit built in.
adfurgerson said:
If all you are wanting is latest firmware with root just let it update then follow this thread.
http://forum.xda-developers.com/showthread.php?t=2784900
If you do decide to unlock bootloader then you have listed steps in wrong order.
1. Root
2. Backup TA
3. Unlock Bootloader
Alternately you could use the dualrecovery installer for step 1 as it has the root exploit built in.
Click to expand...
Click to collapse
I would like to have recovery installed and have a backup of my TA partition just in case
Can you tell me the whole process please?
1-> ?
panyan said:
I would like to have recovery installed and have a backup of my TA partition just in case
Can you tell me the whole process please?
1-> ?
Click to expand...
Click to collapse
1.http://forum.xda-developers.com/xpe...de-root-android-4-4-4-ver-14-4-0-108-t2801587
2.http://forum.xda-developers.com/showthread.php?t=2292598
Backing up TA needs to be done before unlocking bootloader as that is when DRM keys become lost. Also want to mention that I made a Nandroid right after using dualrecovery installer and before unlocking bootloader. When that backup was restored my bootloader became locked again, but I can't swear that the DRM keys remained intact.
adfurgerson said:
If all you are wanting is latest firmware with root just let it update then follow this thread.
http://forum.xda-developers.com/showthread.php?t=2784900
If you do decide to unlock bootloader then you have listed steps in wrong order.
1. Root
2. Backup TA
3. Unlock Bootloader
Alternately you could use the dualrecovery installer for step 1 as it has the root exploit built in.
Click to expand...
Click to collapse
adfurgerson said:
1.http://forum.xda-developers.com/xpe...de-root-android-4-4-4-ver-14-4-0-108-t2801587
2.http://forum.xda-developers.com/showthread.php?t=2292598
Click to expand...
Click to collapse
So the whole process would be:
1) root (http://forum.xda-developers.com/xpe...de-root-android-4-4-4-ver-14-4-0-108-t2801587)
2) backup TA (http://forum.xda-developers.com/showthread.php?t=2292598)
3) unlock bootloader?
4) flash recovery
5) update to latest version OS
6) root
?
panyan said:
So the whole process would be:
1) root (http://forum.xda-developers.com/xpe...de-root-android-4-4-4-ver-14-4-0-108-t2801587)
2) backup TA (http://forum.xda-developers.com/showthread.php?t=2292598)
3) unlock bootloader?
4) flash recovery
5) update to latest version OS
6) root
?
Click to expand...
Click to collapse
Sorry I am at work so my simple replies are even worse than normal.
The easyroot method (towelroot) and the dualrecovery exploit don't require downgrading, so just let it update to latest firmware. If you can't get the OTA for any reason you can flash the latest FTF for your region with flashtool. Then once on latest use dualrecovery installer and TA backup tool. That should have you rooted with recovery and backed up.
Edit...unlocking bootloader is only needed to flash custom ROMs or kernels.
adfurgerson said:
Sorry I am at work so my simple replies are even worse than normal.
The easyroot method (towelroot) and the dualrecovery exploit don't require downgrading, so just let it update to latest firmware. If you can't get the OTA for any reason you can flash the latest FTF for your region with flashtool. Then once on latest use dualrecovery installer and TA backup tool. That should have you rooted with recovery and backed up.
Edit...unlocking bootloader is only needed to flash custom ROMs or kernels.
Click to expand...
Click to collapse
Dont apologise, I really appreciate your help.
I will want to flash custom roms in the future so should I unlock it on day 1?
So the process is:
1) update to latest 4.4.4
2) install dual recovery from here: http://forum.xda-developers.com/showthread.php?t=2647492
3) go into recovery and make a backup
4) make a TA backup with this: http://forum.xda-developers.com/showthread.php?t=2292598
5) root with this: http://forum.xda-developers.com/showthread.php?t=2784900
panyan said:
Dont apologise, I really appreciate your help.
I will want to flash custom roms in the future so should I unlock it on day 1?
So the process is:
1) update to latest 4.4.4
2) install dual recovery from here: http://forum.xda-developers.com/showthread.php?t=2647492
3) go into recovery and make a backup
4) make a TA backup with this: http://forum.xda-developers.com/showthread.php?t=2292598
5) root with this: http://forum.xda-developers.com/showthread.php?t=2784900
Click to expand...
Click to collapse
Step 5 shouldn't be needed as the dualrecovery will take care of rooting. I didn't check the links you posted but if they are the same as I did you should be good.
adfurgerson said:
Step 5 shouldn't be needed as the dualrecovery will take care of rooting. I didn't check the links you posted but if they are the same as I did you should be good.
Click to expand...
Click to collapse
Ok, excellent
What would the process be if I wanted to unlock the bootloader too?
panyan said:
Ok, excellent
What would the process be if I wanted to unlock the bootloader too?
Click to expand...
Click to collapse
Here is a quick rundown....TA backup needs root to work, TA backup saves DRM keys needed for Sony proprietary stuff like audio, video and camera, also if warranty replacement is needed. DRM keys are lost when bootloader is unlocked, also internal storage is wiped. If unlocking a brand new phone then nothings lost, but if you have apps, pics, etc. then you will need to back them up first. I can't remember if I needed to rerun the dualrecovery after unlocking or if recovery was intact. I do know that restoring a Nandroid that I made before unlocking bootloader to phone after it was unlocked caused a soft brick until I unlocked it again. Maybe @blueether could double-check the info I have given you for accuracy as I may be over my head here.
adfurgerson said:
Here is a quick rundown....TA backup needs root to work, TA backup saves DRM keys needed for Sony proprietary stuff like audio, video and camera, also if warranty replacement is needed. DRM keys are lost when bootloader is unlocked, also internal storage is wiped. If unlocking a brand new phone then nothings lost only the DRM keys are lost, but if you have apps, pics, etc. then you will need to back them up first. I can't remember if I needed to rerun the dualrecovery after unlocking or if recovery was intact. I do know that restoring a Nandroid that I made before unlocking bootloader to phone after it was unlocked caused a soft brick until I unlocked it again. Maybe @blueether could double-check the info I have given you for accuracy as I may be over my head here.
Click to expand...
Click to collapse
It all looks about right, I would just change the above a little
blueether said:
It all looks about right, I would just change the above a little
Click to expand...
Click to collapse
Will root and recovery persist after unlocking bootloader? I can't remember if it does or not. Thanks for looking that over, the last I want is to give out erroneous advice.
adfurgerson said:
Will root and recovery persist after unlocking bootloader? I can't remember if it does or not. Thanks for looking that over, the last I want is to give out erroneous advice.
Click to expand...
Click to collapse
I cant unforget either, been too long since I've had a locked BL
1) update to latest 4.4.4 - See FTF thread
2) install dual recovery by [NUT]
3) go into recovery and make a backup - handy if you ever need to get back to stock - I'm not sure if it backs up the TA either
4) make a TA backup and save it on the cloud and on HDD
5) unlock the BL by visiting Sony's dev site and using flashtool
6) re-root / reinstall su if needed
7) make another backup of the TA and call this one unlocked - this can then be used to unlock the BL with out the data wipe
All off the top of my head and not done in ages
blueether said:
1) update to latest 4.4.4 - See FTF thread
2) install dual recovery by [NUT]
3) go into recovery and make a backup - handy if you ever need to get back to stock - I'm not sure if it backs up the TA either
4) make a TA backup and save it on the cloud and on HDD
5) unlock the BL by visiting Sony's dev site and using flashtool
6) re-root / reinstall su if needed
7) make another backup of the TA and call this one unlocked - this can then be used to unlock the BL with out the data wipe
Click to expand...
Click to collapse
Brilliant - thank you very much
You guys have been invaluable!
The other day, I set about installing Cyanogenmod 11 on my Xperia Z2 D5603. I was already rooted on the stock rom 4.4.4 Kitkat 23.0.1.A.0.167. I used flashtool to downgrade to 4.4.2 17.1.2.A.0.314, rerooted it, and installed dualrecovery from this link: http://forum.xda-developers.com/showthread.php?t=2785598
But upon choosing reboot after flashing the custom ROM via TWRP, the phone went dark, and wouldn't turn on. The only response I got was a quick vibration every second or two if I hold down the power button. I could not access recovery either.
I was able to revive it by using flashtool to reflash 4.4.2 17.1.2.A.0.314. I tried the same procedure with AOKP ROM, which had the same result. After trying many different things, I realized that factory reset, or wiping 'system' under advanced wipe would cause this to happen. Flashing without factory reset either returns an error, or finishes, but doesn't actually flash the ROM (stock ROM boots)
How to I flash a ROM without this happening? Any help is appreciated.
Have you unlocked your bootloader? It doesn't sound like it.
These roms require another kernel and you need to unlock your bootloader to install it.
o0 Matt 0o said:
Have you unlocked your bootloader? It doesn't sound like it.
These roms require another kernel and you need to unlock your bootloader to install it.
Click to expand...
Click to collapse
I thought that the fact that it was successfully rooted meant that the bootloader was unlocked. Is this not the case?
How do I unlock the bootloader and install whatever kernel I need?
ljapplebaum said:
I thought that the fact that it was successfully rooted meant that the bootloader was unlocked. Is this not the case?
How do I unlock the bootloader and install whatever kernel I need?
Click to expand...
Click to collapse
Hmm no.
Root ! = unlocked bootloader.
Go to the sony website ( http://developer.sonymobile.com/unlockbootloader/unlock-yourboot-loader) to get instructions to unlock your bootloader.
But with your first assumption in mind, I suggest you read up about it first. Understand the risks and limitations.
o0 Matt 0o said:
Hmm no.
Root ! = unlocked bootloader.
Go to the sony website to get instructions to unlock your bootloader.
But with your first assumption in mind, I suggest you read up about it first. Understand the risks and limitations.
Click to expand...
Click to collapse
Perfect! I unlocked the bootloader by using the instructions on sony's website. It did the trick, and CM11 is running successfully.
Thanks so much!
I have mine updated to 5.1.1 and the bootloader is unlockable. However, the rooting instruction is confusing for this version.
I am looking for the definite solution for rooting (if it is required to unlock the bootloader, should I backup TA partition first?) 100% stock 5.1.1.
Frankly, I don't want to mess with Kingroot or similar tools from China.
I'm interested in this as well. Sent for warranty repair and came back with 5.1.1. Looking for recommended way to root and backup TA (though I have the original backup somewhere)
http://forum.xda-developers.com/xperia-z-ultra/general/guide-how-to-root-install-recovery-t3210207
I managed to root the device. Here is a guide:
http://forum.xda-developers.com/xperia-z-ultra/general/comprehensive-guide-rooting-5-1-x-t3219502
This is how i did it...downgraded to 4.4.4 and root it,TA backup, unlocked the device, updated to 5.1.1 with stock ftf installed the new recovery an flashed the TWRP after that flash the SuperSU zip and done...
fnldstntn said:
This is how i did it...downgraded to 4.4.4 and root it,TA backup, unlocked the device, updated to 5.1.1 with stock ftf installed the new recovery an flashed the TWRP after that flash the SuperSU zip and done...
Click to expand...
Click to collapse
That's a waste of time. OP has an unlockable bootloader, so he just has to:
- Flash recovery
- Flash SuperSU
- Reboot
Klaos3000 said:
That's a waste of time. OP has an unlockable bootloader, so he just has to:
- Flash recovery
- Flash SuperSU
- Reboot
Click to expand...
Click to collapse
unlockable =/= unlocked
mingkee said:
unlockable =/= unlocked
Click to expand...
Click to collapse
Unlocking the BL is still FAR quicker than going through that hellish process for locked bootloaders. It's like trying to juggle with your hands tied to your back, but they're not really tied. Not sure why WE are arguing though. You provided a guide for a locked bootloader, while I gave one for unlocked. What OP decides to do is currently a mystery.
Klaos3000 said:
Unlocking the BL is still FAR quicker than going through that hellish process for locked bootloaders. It's like trying to juggle with your hands tied to your back, but they're not really tied. Not sure why WE are arguing though. You provided a guide for a locked bootloader, while I gave one for unlocked. What OP decides to do is currently a mystery.
Click to expand...
Click to collapse
Here is a deal: unlocking bootloader will remove DRM key. The only workaround is to backup TA partition. However, doing such also requires root, so you have to root before unlocking bootloader.
Don't you know your method is no brainer???! But dealing with DRM key is another story.
Hello !
Frankly you should try with kingroot it's not really a big deal it's quicker and don't worry you will not mess up your phone. I did the same on mine, and it's quick...
LordBli said:
Hello !
Frankly you should try with kingroot it's not really a big deal it's quicker and don't worry you will not mess up your phone. I did the same on mine, and it's quick...
Click to expand...
Click to collapse
Kingroot does not work with 5.1.x, sorry.
I still have to rollback to 4.4.x and use dualrecovery method 3.
mingkee said:
Kingroot does not work with 5.1.x, sorry.
I still have to rollback to 4.4.x and use dualrecovery method 3.
Click to expand...
Click to collapse
Okay, so roll back to KitKat, root, backup your TA, unlock bootloader, and then update to 5.1.1 again. You'll then be able to just flash a recovery and root. If you don't care about the TA partition, then unlock bootloader and flash recovery and root.
Be aware that if your device is still under warranty, it'll be voided the second you lose the DRM keys (TA). If you're not under warranty anymore, it doesn't make any difference. If your device has to go into repairs down the road, it won't matter since you don't have warranty either way. But if you have, it's a good idea to back it up.
Also, the X-Reality engine etc. were at one point dependent on the TA partition, but this changed on KitKat, so X-Reality still works on an unlocked bootloader (even though it's really bad).
Klaos3000 said:
Okay, so roll back to KitKat, root, backup your TA, unlock bootloader, and then update to 5.1.1 again. You'll then be able to just flash a recovery and root. If you don't care about the TA partition, then unlock bootloader and flash recovery and root.
Be aware that if your device is still under warranty, it'll be voided the second you lose the DRM keys (TA). If you're not under warranty anymore, it doesn't make any difference. If your device has to go into repairs down the road, it won't matter since you don't have warranty either way. But if you have, it's a good idea to back it up.
Also, the X-Reality engine etc. were at one point dependent on the TA partition, but this changed on KitKat, so X-Reality still works on an unlocked bootloader (even though it's really bad).
Click to expand...
Click to collapse
Here is what I did as mentioned on the post linked on earlier post.
Download the latest ROM with Xperifirm, and 4.4.x ROM found in a sticky on the general section.
Pack the 5.1.X ROM as flashable pre-rooted.
Use Flashtool to rollback to 4.4.x, completely wipe, made initial setup and enable debug, and install recovery.
Install pre-rooted ROM through TWRP.
Backup TA partition and device data.
Unlock bootloader.
Restore TA partition and device data.
Done.
So I rooted this phone 1 or 2 years ago and now I want to give this phone to my uncle. I read on some other sites to remove the root you just have to delete some folders etc and you're good. I did that but twrp is still on the phone.
I want to make it so the phone is no longer rooted and relock the bootloader so that it doesn't have the "do not trust this device" message on it
The build number it has installed is 34.4.A.2.85
hello. I'm XP docomo user here. let me tell you about my experience here. my bootloader unlock allowed was initially no. i backed up my ta partition before i force my bootloader allow to be yes. it was a successful attempt and i went straight unlocking my bootloader. then i attempted to flash back my ta for fun. the bootloader was automatically locked and the allow was no again. twrp recovery also gone lol. i don't know whether this will okay for you
the main point is backup your ta partition before unlocking the bootloader. it has drm keys which really vital to xperia camera as well as x reality mode/ super vivid. once you unlocked the bootloader, the drm keys will be gone for good unless you've it backed up.
i think restoring the ta partition which is created before unlock is the best way to relock the bootloader again.
first restore the ta partition, download latest firmware on xperifirm, use flashtool to flash ftf created by xperifirm. then, voila.
friendly reminder, flash only ftf supported for your variant. (eg. flash only f8131 ftf for f8131, SO-04H ftf for SO-04H, etc)
DO NOT ATTEMPT TO FLASH OTHER PERSON'S TA PARTITION OR YOU WILL GET ETERNITY HARD BRICK
If you didn't back up your TA partition, you can NOT unlock, as the previous poster said, trying to flash one from a different device will irrecoverably brick your one.
You can flash stock with Flashtool (the one by Androxyde, not Sony Flash Tool, they are different) though. While at it, you might give SailfishOS and Ubuntu Touch (alternative, Linux-based OSes) a shot.