I see people unlocking bootloader and rooting. However, no one mention about DRM backup and restoration. Anyone here knows if all Sony X series phone can have its TA backup?
ataraxist said:
I see people unlocking bootloader and rooting. However, no one mention about DRM backup and restoration. Anyone here knows if all Sony X series phone can have its TA backup?
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Since XA2 and below, there is no way to backup the TA partition and no way to restore and lock the bootloader
Related
will restoring ta partition unroot my phone and will i be able to get ota updates back?and how should i unlock my bootloader without providing my imei to the sony people?
Hello everyone, I did my best to help a few people in Q&A section, but now, I have a few questions myself, all of them, regarding mysterious TA partition.
My C1905 came out of the box with branded 15.1.C.2.8 firmware. One of the first things I did after rooting the device was backing up my TA partition, knowing that I will sooner or later unlock the bootloader. However, I then cross-flashed unbranded C2005 15.2.A.2.5 firmware. My questions are:
1)Do I need to backup TA partition again on a new firmware to be able to relock my bootloader without changing it? Does the TA partition vary between firmwares?
2)Will changing my firmware again to official 4.2.2 for C1905 (which should be released within 2 months) require my to back it up again? Is the C2005's TA partition different than C1905's?
3)Just out of curiousity, what exactly does the TA partition contain? From what I've read, it stores unique "DRM keys", but that doesn't tell me much. Are these keys linked with any hardware (like - for comparison - Samsung's "EFS" folder stores IMEI, MAC adress product code etc and without it, phone has very limited capabilities), or is it just more like "locked bootloader certificate"?
I just want to clear that up, thanks in advance for answering.
3) TA partition contains DRM(Digital Rights Management ) keys, as you said, and other bootloader and hardware related information.
As for the relocking part the problem is the DRM keys...If you read some of the wiki article i linked then you will understand how they are being used in order to prevent locking the bootloader again.
Some software requires those to run, Ex:Bravia Engine2(we dont have that in our phones, but if we had and unlocked the bootloader we wouldn't be able to use it).
1),2)No, you have unlocked your bootloader and your DRM keys are gone, you have them only in your back up. If you want to relock then you will restore your backup while in stock rom-kernel.
stamatis said:
1),2)No, you have unlocked your bootloader and your DRM keys are gone, you have them only in your back up. If you want to relock then you will restore your backup while in stock rom-kernel.
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I think you didn't fully understand the first question. Can I backup TA of my current firmware and then use that back up to relock bootloater WITHOUT changing it back to the stock 15.1.C.2.8? Or do I HAVE to roll back to stock firmware and only then I will be able to relock it? Or maybe I can use the stock backup on any firmware, because TA doesn't change? In other words, can I relock the bootloader on other ROM than stock?
WoJtOn said:
I think you didn't fully understand the first question. Can I backup TA of my current firmware and then use that back up to relock bootloater WITHOUT changing it back to the stock 15.1.C.2.8? Or do I HAVE to roll back to stock firmware and only then I will be able to relock it? Or maybe I can use the stock backup on any firmware, because TA doesn't change? In other words, can I relock the bootloader on other ROM than stock?
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I think i answered:laugh: haha.
It is recommended to be on stock. I wouldn't try it with custom rom due to the possibility of hard brick.
Hey, I'm about to sell my phone, so I need to get it to its factory state. Prefably so that the guy that buys it could send it over for repairs if needed.
And so I did not backup the TA partition. From what I've read that means no relocking the bootloader. Fine.
But how do I go back to the original 4.1.2 sony-branded system?
I'm currently on CM11. Can I just use Sony Companion to perform the update, is it safe? What steps should I undertake?
As far as I know, Sony Update Service won't work with unlocked bootloader (I may be wrong), however, you just need Flashtool and a FTF from the latest stock firmware for Xperia M single SIM (currently at 15.1.C.2.8)
Sorry mate but you can't lock your bootloader without DRM keys(TA PARTITION BACKUP).
You can flash stock ROM using FTF flashtool and but i cant relock your bootloader but you will get stock rom back.
Warranty is void now!!
Sh!t. That's not good.
Thank you guys for answers!
One more thing.
Is it possible to receive OTA updates after I unlocked bootloader and flashed the stock firmware with flashtool?
No once bootloader is unlocked it bricks the device doing ota updates
Sent from my C1905 using xda premium
Sh!tness. So I guess I'm stuck with the phone forever.
Thanks!
Further info for future Xperia phones you may buy: when you unlock your bootloader your DRM keys get wiped, without them, OTA updates, Mobile Bravia Engine (in models that have them -- not the case for Xperia M), Track ID, Download Music Info and SensME (alongside some other proprietary apps/features) will not work, even if you flash stock firmware again.
Before unlocking your bootloader it's always recommended to do a TA backup first, so, if you need, you can relock your bootloader to get your DRM keys back and make proprietary Sony apps/features working again. Since you didn't backup your TA partition before unlocking, you are out of luck now and there is no way of relocking your bootloader.
Also, DO NOT EVER TRY restoring a TA backup from another device (even if it's exactly the same model), TA partition contain some unique info and flashing a TA backup from another device will permanently hard brick your phone...
Well that's a very comprehensive answer! Thanks!
I decided to unlock it, then im stuck in bootloop... At first it says failed, then after i press it again, it says succrss, but i got a bootloop...
What causing this problem?
AndreIrawan97 said:
I decided to unlock it, then im stuck in bootloop... At first it says failed, then after i press it again, it says succrss, but i got a bootloop...
What causing this problem?
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When you unlock the bootloader via sony's official way (using fastboot mode) your security related contents (DRM keys) in trim/TA partition gets erased and you will have access to install a new custom rom . But while unlocking is under progress, say for any reason it gets interrupted,there is a chance that all security related data might not be erased fully / In other words there is a chance that TA partition might have been corrupted
Usually when your phone boots its verifies for the intactness of TA/Trim partition, either it should have all security data (locked bootloader) or fully erased security related data (unlocked bootloader), if partial security information is available, it considers that TA partition has been tampered and will refuse to boot
gokukaushik said:
When you unlock the bootloader via sony's official way (using fastboot mode) your security related contents (DRM keys) in trim/TA partition gets erased and you will have access to install a new custom rom . But while unlocking is under progress, say for any reason it gets interrupted,there is a chance that all security related data might not be erased fully / In other words there is a chance that TA partition might have been corrupted
Usually when your phone boots its verifies for the intactness of TA/Trim partition, either it should have all security data (locked bootloader) or fully erased security related data (unlocked bootloader), if partial security information is available, it considers that TA partition has been tampered and will refuse to boot
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So.... How to properly unlock it? And what should i do if i got a bootloop again?
AndreIrawan97 said:
So.... How to properly unlock it? And what should i do if i got a bootloop again?
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Right now if you are able to boot into your phone, leave it, you have already unlocked/relocked it. If you are in the same situation again,
Steps
1) Relock your bootloader via flashtool
2) Now flash a fully bundled sony official ftf via flashtool.(This will ensure that if any discrepencies in TA partition are there, will be corrected)
Note: This will not restore your DRM keys.I am afraid if you have not backed up your DRM keys during first unlocking trail.they are lost.
3) Follow sony's official bootloader unlock method (www.developer.sonymobile.com/unlockbootloader/unlock-yourboot-loader)
gokukaushik said:
Right now if you are able to boot into your phone, leave it, you have already unlocked/relocked it. If you are in the same situation again,
Steps
1) Relock your bootloader via flashtool
2) Now flash a fully bundled sony official ftf via flashtool.(This will ensure that if any discrepencies in TA partition are there, will be corrected)
Note: This will not restore your DRM keys.I am afraid if you have not backed up your DRM keys during first unlocking trail.they are lost.
3) Follow sony's official bootloader unlock method (www.developer.sonymobile.com/unlockbootloader/unlock-yourboot-loader)
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So... Can i just restore TA and unlock it? Because i have a TA backup
AndreIrawan97 said:
So... Can i just restore TA and unlock it? Because i have a TA backup
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Good that you had a TA backup before unlocking.If you restore your TA backup and unlock it again , it will again erase your security keys, which will lead you to where you started.What is your requirement . Unlock your bootloader only if you want to install a custom rom. Believe me, TA partition is not the one to be played with; it can even render your mobile into a costly paper weight(hardbrick), if it gets messed up pretty bad . If you are already unlocked do not try to restore your TA partition,and unlock again.Its already unlocked and doesnt make any sense to unlock it again ; Restore it only when you want to go back to a locked bootloader.
Hi , i have one question how to lock bootloader on Xperia M
I no have backup of TA. Help me.
It's simple: you can't. And you can't just obtain a backup TA from anywhere. Every TA is unique, like how zebras have different patterns and how humans have different fingerprints.