Why does updating not require bootloader unlock but downgrading does? - Android Q&A, Help & Troubleshooting

Can anyone help me understand why when my phone gets an android update it can install it without unlocking the bootloader but if I wanted to downgrade my android version I need to unlock it?

motog31user said:
Can anyone help me understand why when my phone gets an android update it can install it without unlocking the bootloader but if I wanted to downgrade my android version I need to unlock it?
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With updating, it is by system settings or OTA. However with downgrading, the system cannot let you downgrade by default, as there is no system setting for that - you can unlock the bootloader and then downgrade your version.
To answer your question, YES.
You need to unlock the bootloader to downgrade.

Related

[Q] simplist way to unlock bootloader & root

my brother want me to install a new os for him however he is still on stock kernel and os ect 2.3.4 I believe,
what is the simplest, fastest and safes way to unlock the bootloader of his phone,
furthermore can I use flashtool to root his phone and install other kernals ect,
I have tried *#*#7378423#*#* and it says ''yes'' [as his phone is sim unlocked but I know that he has not unlocked the bootloader himself]
thank you for your time and help in advance :good:
The simplist way to unlock bootloader is the official way.. but you will lose warranty and DRM keys.
Callliope said:
The simplist way to unlock bootloader is the official way.. but you will lose warranty and DRM keys.
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how is that??
http://unlockbootloader.sonymobile.com/ , just read very carefully!10 times before you unlock it.

[Q] re-lock bootloader?

with all the security related threats recently i'm realizing i really need to re-lock my bootloader.
any links on how to do this? i've searched and it's all about unlocking and a few on un-rooting.
i need to retain root, but want a locked bootloader so if i lose my phone it's less likely to have its data siphoned.
CWM, unsure of version
thanks!

[ADVICE] Unlock before N update!

Cleaning this up and clarifying as my original post was vague:
It is recommended that you unlock your bootloader before the 7.0 Nougat update. Although it will still be possible the process will be more difficult and risky afterwards.as you will need to use one of the edl mode tools (axon7backup, axom7tool).
The easiest way is to download this kit f you have the A2017U: (I can't speak to other models) (This kit and instructions are thanks to @jcadduono)
https://build.nethunter.com/misc/axon7/AXON7-A2017U-BL-UNLOCK-KIT.zip
https://build.nethunter.com/misc/axon7/INSTRUCTIONS.txt
The basic steps, which the above zip with take you through in detail are:
1. Flash Official B20 , enable OEM UNLOCKING after flashing.
2. Flash BLFastboot zip provided by ZTE when they had unlock method.
3. Enable OEM UNLOCKING in Developers Option
4. Boot to Bootloader
5. type : fastboot oem unlock
6. Done
Note: If you do not have the OEM UNLOCKING flag set in developer options you will get a soft brick. Also bear in mid this will wipe data.
All that being said I've heard Nougat to is going to be great from those in the know. In their words ”Well worth the wait! Hang in there!” from a HIGHLY credible source.
Why would anyone relock before update? I do agree anyone who wants to unlock should do it now.
lokissmile said:
For anyone looking to bootloader unlock, I've heard that the methods might change when the N update rolls out. It's a major update and although I personally don't have N and can't get a direct answer because those who know for sure are under NDA. I can tell you that the advice given to me is to not re-lock. So if you are thinking of unlocking your bootloader I'd do it soon while the methods are stable. Google confirmed that daydream is certified in an upcoming update so the daydream version of the stock ROM has been through googles QA. Might as well get ready now, we will probably have another surge of custom ROMS shortly after. I'm just sharing what I think is a best practice.
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OK, so just to make it quick, for everyone, unlock your bootloader sooner than later. It is safe since you can revert it to a locked state at any time later.
lafester said:
Why would anyone relock before update? I do agree anyone who wants to unlock should do it now.
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I do it on occasion to test things I'm working on. Better to warn people who might do it to get PoGo or SafetyNet working I figured.
lokissmile said:
I do it on occasion to test things I'm working on. Better to warn people who might do it to get PoGo or SafetyNet working I figured.
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No need to bootloader lock an Axon 7 to get SafetyNet (Android Pay, PoGo, etc). Just do it the XDA way. But never relock!!!!
Could one of you guys explain whats so dangerous about relocking bootloader since u seem to know something I don't.
I have unlocked and relocked my bootloader several times by fastboot oem lock and restoring my stock fbop partition.
Have I done something wrong?
Regards,
mischa_martin
mischa_martin said:
Could one of you guys explain whats so dangerous about relocking bootloader since u seem to know something I don't.
I have unlocked and relocked my bootloader several times by fastboot oem lock and restoring my stock fbop partition.
Have I done something wrong? [emoji14]
Regards,
mischa_martin
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Read the OP.
I think what the op is trying to say is that by unlocking the bootloader you won't get ota updates. You would need to wait until a twrp flashable update is out or a rom running Android 7.
stevecaboose said:
I think what the op is trying to say is that by unlocking the bootloader you won't get ota updates. You would need to wait until a twrp flashable update is out or a rom running Android 7.
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That's how it's been since modifying the bootloader was a thing. Unlocked bootloader = no OTA.
tzbigworm said:
That's how it's been since modifying the bootloader was a thing. Unlocked bootloader = no OTA.
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Click to collapse
@stevecaboose
Unlocking Bootloader = Yes to OTA's.
Modding System and Boot = NO OTA's
hope that clear things up.
Close enough lol!
To be clear, it would be best to unlock before N is pushed out. I have it on good authority that unlocking your bootloader after you update to N will be more difficult and risky. Relocking would put you in the same situation. It's trivial to return to stock system+boot with an unlocked bootloader and TWRP and then the OTA will come through just fine. Or you can just wait for the TWRP flashable N stock ROM.
So to be clear, since I'm not 100% sure what affects the "system" and "boot" areas: I can unlock my BL using only guide 2 in this link ( https://forum.xda-developers.com/axon-7/how-to/guide-install-twrp-unlock-bl-flash-t3517379 ) and still get OTAs? If I install TWRP does that make me OTA-ineligible?
ScaryBugThing said:
So to be clear, since I'm not 100% sure what affects the "system" and "boot" areas: I can unlock my BL using only guide 2 in this link ( https://forum.xda-developers.com/axon-7/how-to/guide-install-twrp-unlock-bl-flash-t3517379 ) and still get OTAs? If I install TWRP does that make me OTA-ineligible?
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TWRP/BL unlock doesn't affect OTA, ROOT does.
raystef66 said:
TWRP/BL unlock doesn't affect OTA, ROOT does.
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Click to collapse
You're totally wrong there,
TWRP will affect OTA's if the OTA need to check/patch recovery, BUT been Bootloader Unlock will NOT effect OTA.
To manage a clean/successful OTA's installation, you need to be FULL STOCK. (System, boot, Recovery, aboot if the OTA need to patched).
I think the OP was trying to say that it's possible current tools will not work to unlock the bootloader after the 7.x ota is installed.
DrakenFX said:
You're totally wrong there,
TWRP will affect OTA's if the OTA need to check/patch recovery, BUT been Bootloader Unlock will NOT effect OTA.
To manage a clean/successful OTA's installation, you need to be FULL STOCK. (System, boot, Recovery, aboot if the OTA need to patched).
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I'm not fully agreed with that. You can install OTA's when you receive it, download it, install it when first booted into twrp cache. Only if you're not rooted. When you're rooted first unroot and in principle this should work.
There are several cases on internet about that. Even I did it with an unrooted but TWRP-ed Zopo C2. Received an OTA and installed it.
Im always glad to learn but IMO there are some possibilities to do the ota after all. But I am willing to accept it's a general fact that twrp could affect the normal OTA.
Edit : let's wait and see when B10 is rolling out and if I get a notification about that and if I can install it as a normal OTA(not with SD) with TWRP. Keep you updated:cyclops:
Noob here, forgive me ...
So what is the best way to only unlock bootloader without flash twrp?
A2017U, B29.
Thanks
eladmitz said:
Noob here, forgive me ...
So what is the best way to only unlock bootloader without flash twrp?
A2017U, B29.
Thanks
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I`m on the same boat. What should be the safer procedure to unlock BL an still get the N OTA?
eladmitz said:
Noob here, forgive me ...
So what is the best way to only unlock bootloader without flash twrp?
A2017U, B29.
Thanks
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felipe.vella said:
I`m on the same boat. What should be the safer procedure to unlock BL an still get the N OTA?
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Click to collapse
1- Download Official B20 from ZTE SITE (look Software Updates for the 6gb variant)
2- look in the forum for the B20fastboot zip file
3- Move both files to your SDCARD.
4- Enable OEM Unlocking under Developers Option
5- boot to stock recovery.
6- Install B20 official update via SDCARD (this will wipe Data)
7- boot and re-enable OEM Unlocking
8- boot to recovery and install B20fastboot zip
9- boot to Bootloader and Unlock bootloader using this command.
Code:
fastboot oem unlock
If I remember correctly will reboot and factory reset the device , you'll need to re-enable OEM UNLOCKING and boot to Bootloader to flash TWRP 3.0.3 USING fastboot commands

[Q]How to lock bootloader on Xperia 10 plus ?

Hi there . Recently i just rooted my phone and unlocked the bootloader but i want to roll it back to stock status.
I read a lot and i can not understand ,
Is it possible to lock the bootloader on that phone or not ? If yes ,how ?
EDIT : I tried with fastboot commands oem relock but it didn't work .I removed the root but still need to lock the bootlodaer
Hey, you can flash official firmware into your device and get back to the stock firmware without root. But you can't re-lock the bootloader. I have tried so many command in fastboot and any of em doesn't work.
XOBOT.V2 said:
Hey, you can flash official firmware into your device and get back to the stock firmware without root. But you can't re-lock the bootloader. I have tried so many command in fastboot and any of em doesn't work.
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I was able to remove the root manually so no need to reflash stock frimware,but about bootloader still not successed to lock it even via flash tool BLU option. There should be warning that you can't lock it once its unlocked damn..
diw4k said:
I was able to remove the root manually so no need to reflash stock frimware,but about bootloader still not successed to lock it even via flash tool BLU option. There should be warning that you can't lock it once its unlocked damn..
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Yes indeed. I've tried that too. apparently you can't relock the bootloader in newer devices. Only thing to do right now is, hope that Sony will release some kind of commands to relock the bootloader. Unless there's no other way.

Unroot and relock bootloader in order to get OTA updates

Hi,
I'm using HD01BA (= EU version) with unlocked bootloader and root with Magisk. I understand that updating OOS or updating Magisk is quite annonying as there's no TWRP and as it needs specific precautions such as disabling Magisk modules and reinstalling them after updating.
Since I now barely use root, I think I would benefit more from being able to get OTA updates than having root. I'd like to know how to unroot - and relock bootloader if necessary - without bricking the phone.
Would I have to wipe everything ? Will unrooting enable OTA updates or do I need to relock bootloader as well ?
Thanks
Edit : Wrong category, I asked moderators to delete this and have posted it in Questions & Answers
Use MSMTool. it will take care everything for you.
Lossyx said:
Use MSMTool. it will take care everything for you.
Click to expand...
Click to collapse
Thanks for the reply. Will it erase all data ? Will it relock bootloader ?
DrBazinga said:
Thanks for the reply. Will it erase all data ? Will it relock bootloader ?
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Click to collapse
It will erase everything and lock the bootloader, yes.
Is there a way to only unroot (flashing a clean boot maybe?) in order to get OTA updates? Even if the bootloader remains unlocked
DrBazinga said:
Is there a way to only unroot (flashing a clean boot maybe?) in order to get OTA updates? Even if the bootloader remains unlocked
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Click to collapse
Yes you can unroot by flashing stock boot.img, but why?
You get new updates when they are available through system updates in your settings/updater app regardless of the bootloader/root conditions.
The additional steps that has to happen after the OOS update is to keep Magisk/root.
Hw4ng3r said:
Yes you can unroot by flashing stock boot.img, but why?
You get new updates when they are available through system updates in your settings/updater app regardless of the bootloader/root conditions.
The additional steps that has to happen after the OOS update is to keep Magisk/root.
Click to expand...
Click to collapse
I don't think I do, I'm still on 10.0.9 and there's no update showing up, even in the settings. I remember reading somewhere that on this phone, unlocking bootloader or rooting (I forgot which one) disables updates notifications.
What bothers me is that i) if I want to update OOS I need to delete all Magisk modules then reinstall them to avoid bootloop and ii) if I want to update Magisk, I'd have to do all the steps again including flashing a patched boot, right ?
In addition, Magisk may no longer be able to hide bootloader unlocking from apps with Android 11.
DrBazinga said:
I don't think I do, I'm still on 10.0.9 and there's no update showing up, even in the settings. I remember reading somewhere that on this phone, unlocking bootloader or rooting (I forgot which one) disables updates notifications.
What bothers me is that i) if I want to update OOS I need to delete all Magisk modules then reinstall them to avoid bootloop and ii) if I want to update Magisk, I'd have to do all the steps again including flashing a patched boot, right ?
In addition, Magisk may no longer be able to hide bootloader unlocking from apps with Android 11.
Thanks
Click to expand...
Click to collapse
You can use Oxygen Updater https://play.google.com/store/apps/details?id=com.arjanvlek.oxygenupdater
And the bootloader unlock check is Google's doing with hardware key attestation. This may not get cracked.

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