Is it possible to have a locked bootloader and root simultaneously? - Google Pixel 2 Questions & Answers

I was wondering if there is a way to disable the warning screen or relock the bootloader while keeping the root and recovery.
Everytime i try it it say it can no longer find a valid operating system.

plain and simple, not there is no way for our phones. if your bootloader is unlocked, the warning screen will always show and your bootloader must be unlocked in order for magisk to run and root to be allowed.

Currently no. The reason is that to have root, you have to have a patched boot image, and to have a patched boot image, you need to be able to have an unlocked bootloader to allow flashing of /boot from recovery. "Locked" rooting would involve an exploit that would undoubtedly get fixed quickly. Also, keep in mind that the Pixel 2/XL do not have dedicated recovery partitions, but that recovery itself also resides in /boot.

Related

Can't boot with locked bootloader...

Hi there:
So, I've decided to unroot and relock my Xoom 4G, in anticipation of the official JB release. When I lock the bootloader (fastboot oem lock), the device locks, reboots, then comes up with the "Failed image SOS 0x0002" error. If I then unlock the bootloader, it boots into Honeycomb just fine.
Now, I'm assuming that I need my bootloader locked to do the upgrade, because there is a small update I'm notified on (HLK75F), and when I try to install it, the devices reboots, and I get the yellow bang and can go no further until a hard reset.
So, I can't boot with locked bootloader; can't do updates with an unlocked bootloader.
Can anyone advise?
Thanks!
shmengie said:
Hi there:
So, I've decided to unroot and relock my Xoom 4G, in anticipation of the official JB release. When I lock the bootloader (fastboot oem lock), the device locks, reboots, then comes up with the "Failed image SOS 0x0002" error. If I then unlock the bootloader, it boots into Honeycomb just fine.
Now, I'm assuming that I need my bootloader locked to do the upgrade, because there is a small update I'm notified on (HLK75F), and when I try to install it, the devices reboots, and I get the yellow bang and can go no further until a hard reset.
So, I can't boot with locked bootloader; can't do updates with an unlocked bootloader.
Can anyone advise?
Thanks!
Click to expand...
Click to collapse
You can do updates with an unlocked bootloader as long as it is stock. The lock doesn't have anything to do with that.
However: The fact that it can't boot when locked suggests that your not back to 100% stock. Re-download images for your Xoom from http://developer.motorola.com/products/software/ and re-flash them.
airesch said:
The fact that it can't boot when locked suggests that your not back to 100% stock.
Click to expand...
Click to collapse
Incorrect. If you've been running with your bootloader unlocked, then decide to lock it, 99% of the time it won't boot, even if you're running 100% stock. For example, if you're on stock 4.0.4 with an unlocked bootloader, then decide to re-lock it, it won't boot. If your bootloader is unlocked, the only way your Xoom will boot after locking it is to install one of the firmware packages listed for your device at http://developer.motorola.com/xoomsoftware, as you correctly pointed out. Once you flash those images with fastboot, you can then lock your bootloader and it will boot. Once it boots, just keep applying the system updates as it prompts you and eventually you'll end up on the latest version available for your device.
oldblue910 said:
Incorrect. If you've been running with your bootloader unlocked, then decide to lock it, 99% of the time it won't boot, even if you're running 100% stock. For example, if you're on stock 4.0.4 with an unlocked bootloader, then decide to re-lock it, it won't boot. If your bootloader is unlocked, the only way your Xoom will boot after locking it is to install one of the firmware packages listed for your device at http://developer.motorola.com/xoomsoftware, as you correctly pointed out. Once you flash those images with fastboot, you can then lock your bootloader and it will boot. Once it boots, just keep applying the system updates as it prompts you and eventually you'll end up on the latest version available for your device.
Click to expand...
Click to collapse
The cause of that 99% is because rooting the Xoom also changes the boot image (to set certain parameters,) and unless you have the clean boot image (of the right version that your updates are at,) it's not 100% stock. Even then, sometimes the rooting process (or if you have also installed busybox and not uninstalled it,) can update timestamps on folders in the system image which will foul up the checksums. I have restored a nandroid of my stock installs, re-flashed the boot and recovery to the right versions, and had it relock successfully several times. The trick is to have those images so all the checksums line up.
Lesson here: If it won't boot when locked, then it wasn't exatcly 100%.
Thanks, guys. I will try redownloading the img files and go through the fastboot commands again.
airesch said:
Lesson here: If it won't boot when locked, then it wasn't exatcly 100%.
Click to expand...
Click to collapse
False. Run unrooted pure stock 4.0.4 on an unlocked bootloader. After that, lock your bootloader and watch what happens.
Also, rooting only modifies your boot image if you use one of those pointless universal root methods. If you simply unlock, flash a mod recovery, and flash the Superuser ZIP from androidsu.com, it leaves the boot image untouched. An insecure boot image is only needed if you want root access in ADB, which 99% of rooted users couldn't care less about.
Sent from my Nexus S using Tapatalk 2

heyy my q.. is abt boot loader and rooting

rooting mobile phone is also unlocks tha boot loader...?? what does exact it means how to unlock boot loader and rooting and unlocking boot loader is same thing...??
Sent from my SM-G7102 using Tapatalk
I searched the forums for you and I found this post:
theq86 said:
Root
Rooting a device is a method to gain full access to the operating system. With root you can do all the administrative stuff, write to locations normally restricted to the system and customize your device deeper.
Root enhances your privileges and you are able to change almost anything inside of your rom.
The rooting, however, affects ONLY your operating system (Android)
Unlocked Bootloader
In most devices, the Bootloader is the instance that calls the operating system (Android) and manages direct access to the device's partitions. Having an unlocked bootloader enables you to flash custom roms, custom kernels, recoveries and so on.
Bootloader and Rooting Teamplay
Often it is the case, and so, too in our devices, that a locked bootloader also locks write access to several partitions like the system partition. This is the reason why rooting is not able without unlocked bootloader. Rooting needs write access to the system partition (for storing the superuser binary and the superuser app)
Without unlocked bootloader, only a temporary half-root can be achieved.
Click to expand...
Click to collapse
I would have linked to the topic but I don't have the 10 post requirement.

Re-lock bootloader without erase?

I really hate that boot screen that makes you think your phone is going to blow up because the bootloader is unlocked... I realize that having it unlocked is perfectly fine, and with Magisk, all the Google security stuff still works just fine.. I also know that an unlocked booloader makes it much easier to flash updates (flash-all but remove the -w) ... So please don't try to explain why I should leave my bootloader unlocked.
WIth my HTC phones, unlocking the bootloader would erase the phone (obviously, and just like the Pixel 2). Locking the bootloader wouldn't erase the phone on the HTC, but with the Pixel 2, the instructions say that it WILL ERASE THE PHONE.
With the HTC, the wipe happened in recovery, so if I had TWRP installed, the phone wouldn't erase... I could easily switch between locked and unlocked, and as long as I had TWRP installed, the phone would "think" it was going to erase, but I stopped it.
So my question is... Does the Pixel 2 wipe the phone on lock/unlock through recovery? If so, can I lock the phone with TWRP installed in recovery and prevent that lock? I know I can make a backup and try it and see, but since the Feb update, getting into a decrypted recovery has become a pain (remove pin/password, reboot, reboot to recovery, do what you want, reboot to system, add the pin/password, add fingerprint, open EVERY SINGLE APP THAT USES FINGERPRINT AND SET LOGIN AND REGISTER THE FINGERPRINT - it frustrates me, in case you can't tell).
You cannot flash TWRP unless you are unlocked so at this time there is no way to unlock the bootloader without a full wipe.
I think you misunderstood the question. I have unlocked the bootloader (let it wipe) and installed TWRP. I want to know if the re-lock will wipe through recovery (and therefore be stopped by TWRP) or if it does the wipe using some other method (and therefore wiping regardless).
1. You won't be able to maintain your userdata while switching between locked and unlocked states.
2. You will likely not be able to boot your device either after locking your phone.
For 1)
The Pixel 2 enables FBE (filesystem-based encryption) by default for your userdata partition. The encryption keys are derived from a hardware secret (accessible only from TrustZone), the RSA public key that was used to sign the boot image and a flag (whether it is locked or unlocked). The latter parameters are provided by the bootloader (lk) to the Keymaster trustlet (running in TrustZone).
If any of these parameters change, then the encryption keys will change as well. As a result, your files will remain inaccessible even if you were hypothetically able to flip the lock state.
For 2)
Unlocking the bootloader (fastboot flashing unlock) will disable verification of the boot image. TWRP is installed by modifying the boot image (in both the "a" and "b" slots) which invalidates the Verified Boot signature that covers this boot image (stored in the vbmeta partition). When the device is locked again, the bootloader will fail to pass the signature check and stay in the "red" boot state. At that point I guess you have a brick (I have not tried this myself for obvious reasons).
Source: reading the lk source code and various Android documentation such as https://source.android.com/security/encryption/file-based
Lekensteyn said:
When the device is locked again, the bootloader will fail to pass the signature check and stay in the "red" boot state. At that point I guess you have a brick (I have not tried this myself for obvious reasons).
Click to expand...
Click to collapse
The signature of the Custom ROM (Official LineageOS) can be integrated into the bootloader before re-locking the bootloader.
But this is the problem: "Lineage Recovery is also built in userdebug mode, that's a problem. When Lineage recovery is built this way, it allows any package, signed or unsigned, to be installed on your phone. This effectively negates the benefits of locking the bootloader. [...] In fact most custom ROMs simply use TWRP or another third party recovery which has the same issues as they are designed to never even look at the signatures of the packages they are flashing to your device."
"A discussion about bootloader locking/unlocking... AKA I want to relock my bootloader, should I?: LineageOS"
https://www.reddit.com/r/LineageOS/comments/n7yo7u

Lock/Unlock boot loader?

Can we re-lock the boot loader on Pixel devices if the device is rooted and modded with custom boot and recovery partitions? I heard that it will brick the device when you try to re-lock the boot loader.
Also what if recovery partition ever gets corrupted and a user never had enabled OEM unlocking for the boot loader in the developer option as set as default, and the boot loader is locked as is, user can'f flash the factory images and /or full OTA from ADB.
I'm no expert but from what I've read 'Never relock the bootloader unless you are 10000% sure it's full stuck' and if I remember correctly there is no recovery partition on A/B slot builds which is why a brick is a non recoverable scenario (check that out just in case I'm wrong)
I've unlocked my bootloader and it ain't getting relocked after reading through heaps of bricked pixel threads, best to be safe than bricked.
Yep @junglism93 is right, only re-lock bootloader if you are 100% stock and unrooted to avoid bricks. Also Pixel doesn't have a recovery partition, everything happens in the boot partition, that means that in case of problems if you don't want to reflash the whole factory image (which needs unlocked bootloader), you can just reflash boot.img on slot-a and slot-b (which needs unlocked bootloader anyway).
I unlocked my bootloader straight after the unboxing and I can tell it's like a life saviour, if any problem occurs you can always solve it with an unlocked bootloader.
TENN3R said:
Yep @junglism93 is right, only re-lock bootloader if you are 100% stock and unrooted to avoid bricks. Also Pixel doesn't have a recovery partition, everything happens in the boot partition, that means that in case of problems if you don't want to reflash the whole factory image (which needs unlocked bootloader), you can just reflash boot.img on slot-a and slot-b (which needs unlocked bootloader anyway).
I unlocked my bootloader straight after the unboxing and I can tell it's like a life saviour, if any problem occurs you can always solve it with an unlocked bootloader.
Click to expand...
Click to collapse
That seems like a crazy partition scheme on the device. I can't stand that dreaded unlock screen at the startup. plus you never know for sure if that OEM unlock switch in the developer menu will stay enabled all the time and not accidentally get disabled after modding your device so you're just having a very vulnerable device if it is modded...eh?
I wonder if there is a pure Android device which does not have such restrictions and/or actually comes pre-rooted?

Genuine Bootloader

Can the oem bootloader be replaced?
If the bootloader is locked, can you be sure the Recovery/System partitions are untouched?
Recovery - where it doesn't matter whether it's Stock or Custom - simply is a menu you can select actions to perform and apply, the lock state of device's bootloader basically isn't of interest.
System partition can get tampered as soon as it gets mounted as RW where it doesn't matter whether device's bootloader is locked or unlocked, but device's Android got rooted or not.
Thank you for replying.
I'm asking about replacing the bootloader system itself and not the recovery.
How can you root without an open bootloader on a modern phone??
The AVB won't let you boot at all(since android 8).
I tried to answer 2nd question in your 1st post here. I can't help it if you didn't realize it.
To answer the question you asked above:
Rooting is the act of unlocking the Android OS to gain complete control over the device through which you can access hidden files or install certain special apps. Rooting Android OS simply means to add Superuser functionality to it.
Again:
Device's bootloader MUST NOT get unlocked in order to root Android. Even device's /system partition must not get touched in order to root Android: hence bootloader's DM-VERITY / AVB must not get disabled.
Last note: I no longer participate this thread ...

Categories

Resources