[Q] Possible to protect flashing of custom rom/kernel/recovery?

[Q] Possible to protect flashing of custom rom/kernel/recovery? - Samsung Galaxy Nexus

Pulling this out of a thread below because it's a slightly different concept.
Is it possible (and the motive would be to at least essentially 'brick' a stolen phone when combined with an anti-theft app), to have at the recovery level - a way to prevent people from flashing new images? Or is this already implemented on a custom recovery? Would there still be a way to bypass even that?
This way, at best all someone could do is steal/sell your phone for parts assuming you have an anti-theft app installed (since obviously they could battery pull, but wouldn't be able to overwrite anything or get past your lockscreen if PIN locked).
Of course the risk being if you forget your password, you're also toast.

And where would you find testers for this?
good day.

Emulation?
I am not certain what's capable, hence the question.
Alternatively start out by having it look for a key/file on your personal computer in order to allow flashing (or maybe on sdcard)
Can fastboot mode read contents from a remote location?

Most likely not possible at all. Recovery and Fastboot are pretty simple. Fastboot can't search and read contents from a remote location.
Cell signal isn't even operating at that level.

I had mentioned this in another thread: rolle3k managed to disassemble the bootloader on the Nexus One, which led to us having custom boot loaders. (See the Blackrose thread in the N1 forum.) Along with that, came the ability to add a password to fastboot commands. This, coupled with having a stock recovery flashed and a screen password makes the device essentially useless to someone else, without repair/jtag. (Not sure about download mode though.)
What we need is a genius like rolle3k to take a stab at disassembling the GNex bootloader, and we would have a lot of options!
Sent from my Galaxy Nexus using Tapatalk 2

Related

Galaxy Nexus Security

Sup all
I've seen a bunch of scattered threads about security issues...But nothing satisfying enough.
Basically, I was thinking about the encryption option we have with ICS on the GN. From what I understand, staying stock with encryption enabled is the safest way to go if you fear of ever losing your phone.
Think about it, if you lose your phone and the "thief" is smart enough, he can get your passwords and data of your the accounts you have (Facebook, Gmail, Twitter, Whatsapp, Skype, etc).
From what I understand, encryption is "kinda" incompatible with cmw. I'm not an expert, but from what I read, you can't access CWM if your phone is encrypted.
Since we obviously want to run roms for the many advantages they give over stock, there must be a way to "fix" that security hole that comes with rooting/unlocking.
Like I said earlier, I'm not expert, but couldn't there be a way to have your device encrypted and running a custom rom at the same time? Something about partitioning your internal "sdcard", or maybe doing something like this if possible
unlock/root-> Flash rom-> encrypt -> lock.
TLDR: How do you effectively keep your phone secured from any unauthorized access when running custom roms?
Thanks

Some infos
http://forum.xda-developers.com/showthread.php?p=27482516
Sent from my Galaxy Nexus using xda premium

Cerberus app.
"Long is the way, and hard, that out of hell leads up to light."

To just safely run a custom ROM: install stock recovery, re-lock the bootloader, disable USB debugging, and create a PIN/password.

crachel said:
To just safely run a custom ROM: install stock recovery, re-lock the bootloader, disable USB debugging, and create a PIN/password.
Click to expand...
Click to collapse
So basically, flash the rom and mods of choice and then restore bootloader and recovery. Easily doable with the toolkit I suppose. Do I also need to unroot to make it anymore secure?
Your answer makes me wonder, what is the benefit then of having encryption on vs locked boot/stock recovery? Couldn't you somehow access data through command lines even with locked boot and stock recovery?
Thanks

la7lou7a said:
So basically, flash the rom and mods of choice and then restore bootloader and recovery. Easily doable with the toolkit I suppose. Do I also need to unroot to make it anymore secure?
Your answer makes me wonder, what is the benefit then of having encryption on vs locked boot/stock recovery? Couldn't you somehow access data through command lines even with locked boot and stock recovery?
Thanks
Click to expand...
Click to collapse
With USB debugging turned off, you cannot issue any commands to the device using ADB via command line. With a locked bootloader, you cannot boot an insecure image to give you root access. With a stock recovery, you do not gave access to the file system. So, as long as you have a lock screen PIN, I can't see how someone can get any data off the device without JTAG or some other hardware hack.
Encryption would prevent even that, given that any data extracted via JTAG would be encrypted.
Sent from my Galaxy Nexus using Tapatalk 2

la7lou7a said:
So basically, flash the rom and mods of choice and then restore bootloader and recovery. Easily doable with the toolkit I suppose. Do I also need to unroot to make it anymore secure?
Your answer makes me wonder, what is the benefit then of having encryption on vs locked boot/stock recovery? Couldn't you somehow access data through command lines even with locked boot and stock recovery?
Thanks
Click to expand...
Click to collapse
If you disable USB Debugging and use a PIN/Password/Face Unlock/Pattern you'll be safe. To access your phone data from pc, you need USB Debugging(with MTP you can't transfer app-data) to be able to use ADB. And to enable USB Debugging, they need the password/pin/...
And then if they want to use recovery, they need to unlock the bootloader(which wipes the device).

Great. Another noobie question:
If you still have root access (with locked boot and stock recovery)
and somehow the rom doesn't boot correctly, because of something like changing the boot animation via root explorer
Without USB debug, can you still get back to a functional device?
Another way to ask the question: Does USB debug/Adb commands function only when the android os is running?
What i mean is that, in case **** happens, you can just use the toolkit to unlock (wipe)/cwm/flash again, correct?
Thanks guys

la7lou7a said:
Great. Another noobie question:
If you still have root access (with locked boot and stock recovery)
and somehow the rom doesn't boot correctly, because of something like changing the boot animation via root explorer
Without USB debug, can you still get back to a functional device?
Click to expand...
Click to collapse
Not without losing all of your data, because with USB debugging off, you would have to unlock the bootloader, which would require a wipe.
la7lou7a said:
Another way to ask the question: Does USB debug/Adb commands function only when the android os is running?
Click to expand...
Click to collapse
Correct, either the Android OS, or if you have a custom recovery (which has it enabled by default).
la7lou7a said:
What i mean is that, in case **** happens, you can just use the toolkit to unlock (wipe)/cwm/flash again, correct?
Click to expand...
Click to collapse
I always say using toolkits is a bad idea -- you should figure out how to do it by issuing commands via ADB and fastboot. But yes, your statement is generally correct.

If you truly want a custom rom to be as secure as stock, it needs to be signed with something OTHER than AOSP public test keys, not rooted, and usb debugging shut off.
Most are signed with test keys. I know BAMF Paradigm is privately signed, but I cannot vouch for others.
http://uncutandroid.com/2011/03/theyre-called-testkeys-for-a-reason/
I've been asking folks to stop using test keys for a while now (as have some hacker/cracker/security nuts), and it has fallen on mostly deaf ears. It takes a rom dev 30 seconds (if he/she is slow) to correct this.

Interesting

Newbie rooting/backup thread (groan...)

In my defence, m’lud, I spent about 6 hours yesterday reading through a great many threads before posting this one. It’s amazing how hard it can be to pick up a slightly unfamiliar technology when it’s not the one you're used to… I spent the latter half of my life in IT (Windows), but really struggle with this phone stuff.
I expect it's just the terminology… when you guys talk about a bootloader, I’m thinking that’s roughly the same as a BIOS on a computer…? Then there’s the “recovery” thingy… is that like a recovery partition on a Windows machine? But then some threads seem to suggest you over-write that when rooting, so is the original factory image lost forever?
My main reason for wanting to root my M8 is to remove all the bloatware HTC put on it. I can read the instructions for rooting here, but I don’t like blindly following anything I don’t understand, for obvious reasons!
I kind of gather that the “ROM” is the operating system… if I root the phone, does that automatically obliterate the existing one, necessitating a new one, or can I just gain the access I need to delete the horrible factory apps, and keep everything else?
I’ve read through several tutorials, and they’re easy to follow, but not easy to understand, if you get me… they’ll say things like download this, flash that… but I don’t really know what’s going on when you flash something – what am I over-writing etc.
Is there a thread anywhere which explains what these various things actually ARE?
Oh, and I’ve been playing various King games for years, and have got a long way. I’ve tried to figure out how to back them up – the King website is possibly the most unhelpful I’ve come across. People mention various utilities (I think maybe Titanium etc), but if they only work on a rooted phone, they presumably can’t be used to back the games up prior to rooting…
Sorry about all this guys – not asking you to re-invent the wheel, but f there are specific threads that already answer my questions to get me started, I’d be VERY grateful
Thanks
Roger

Roger465 said:
In my defence, m’lud, I spent about 6 hours yesterday reading through a great many threads before posting this one. It’s amazing how hard it can be to pick up a slightly unfamiliar technology when it’s not the one you're used to… I spent the latter half of my life in IT (Windows), but really struggle with this phone stuff.
Click to expand...
Click to collapse
Aye, it takes a bit of time to learn all the things and understand them.
Me, after being really familiar with a Sony device had to spend XX hours reading about HTC and after few years there are still things that I don't know
Roger465 said:
I expect it's just the terminology… when you guys talk about a bootloader, I’m thinking that’s roughly the same as a BIOS on a computer…? Then there’s the “recovery” thingy… is that like a recovery partition on a Windows machine? But then some threads seem to suggest you over-write that when rooting, so is the original factory image lost forever?
Click to expand...
Click to collapse
I'd rather say recovery is closer to bios., but bootloader matches too.
Recovery is a partition that all android phones have and it can be accessed in case when the system dies to factory reset and things. Stock recovery is good, but it can't be used to flash things like roms and kernels, so we use TWRP - a custom recovery with many options.
Original recovery is overwritten, but can be restored.
As for bootloader it's kinda like a gate - a locked one prevents booting and flashing of any unauthorized files, like custom recovery for example. Unlocking it removes this restriction. That's one fuction of bootloader, another one is starting up the system - like a bios - and can be accessed by a button combination durning boot up, it's also called hboot. In it you can see some essential info about phone software and boot to recovery.
Roger465 said:
My main reason for wanting to root my M8 is to remove all the bloatware HTC put on it. I can read the instructions for rooting here, but I don’t like blindly following anything I don’t understand, for obvious reasons!
I kind of gather that the “ROM” is the operating system… if I root the phone, does that automatically obliterate the existing one, necessitating a new one, or can I just gain the access I need to delete the horrible factory apps, and keep everything else?
Click to expand...
Click to collapse
ROM is the android itself, drivers, kernel and manufacturer's interface, apps, tweaks, settings. and probably something else I've missed. I think it would be somewhat correct to call this operating system. Rooting is gaining superuser access on the phone - it can be used to give extended functionality to apps, like making modifications in system itself. Pretty similiar to "run as administrator" in windows. Rooting itself won't remove the rom.
Roger465 said:
I’ve read through several tutorials, and they’re easy to follow, but not easy to understand, if you get me… they’ll say things like download this, flash that… but I don’t really know what’s going on when you flash something – what am I over-writing etc.
Is there a thread anywhere which explains what these various things actually ARE?
Click to expand...
Click to collapse
Those should give you a basic knowledge:
https://www.androidcentral.com/dictionary
https://android.gadgethacks.com/news/big-android-dictionary-glossary-terms-you-should-know-0165594/
Roger465 said:
Oh, and I’ve been playing various King games for years, and have got a long way. I’ve tried to figure out how to back them up – the King website is possibly the most unhelpful I’ve come across. People mention various utilities (I think maybe Titanium etc), but if they only work on a rooted phone, they presumably can’t be used to back the games up prior to rooting…
Click to expand...
Click to collapse
Titanium backup is an app used to backup other apps, but it requires root. To get root you need a custom recovery and for it you need an unlocked bootloader.
Unlocking the bootloader will wipe all data from the phone. I'm not aware of many working methods to backup apps and their data.
There's an app called Helium, but there are many complaints that it doesn't fully work. You can try syncing all data to your google account or adb backup.

A lot of the basic terminology is explained here: https://forum.xda-developers.com/showthread.php?p=52484527#post52484527
My responses below in red font:
Roger465 said:
when you guys talk about a bootloader, I’m thinking that’s roughly the same as a BIOS on a computer…?
I'd say that is a pretty good analogy. It's responsible for loading the OS, same as BIOS does on a PC. And as long as you can get into bootloader, the phone is recoverable almost regardless of what else you did (within some limits).
Then there’s the “recovery” thingy… is that like a recovery partition on a Windows machine? But then some threads seem to suggest you over-write that when rooting, so is the original factory image lost forever?
Recovery is the tool for making or restoring backup (and also flashing ROMs and other mods like root). And not the actually backup itself. So that is one important distinction to remember.
Installing custom recovery (TWRP) will overwrite the stock recovery, that is true. You can only have one recovery at a time.
Stock recovery is easy to restore; and the stock recoveries are available on this forum. But stock recovery is close to useless. The only reason you would need stock recovery, is to install an official OTA (over-the-air) upated. And HTC was done updating this phone a long time ago (with Marshmallow) and there will be no more updates. Therefore, no need for stock recovery.
Since you've decided to do to the dark side and root; custom recovery TWRP as vastly more useful than stock recovery (as also mentioned in the previous response). To be honest, I can't say I've booted to stock recovery on this or any HTC device I've owned (and it's been several) even once. Never used it, and never needed to.
I kind of gather that the “ROM” is the operating system… if I root the phone, does that automatically obliterate the existing one, necessitating a new one, or can I just gain the access I need to delete the horrible factory apps, and keep everything else?
Depending on root method (SuperSU or Magisk), root will make changes to the system and/or kernel (which comprise the OS or ROM). It's still the stock ROM, just with some minor changes to allow superuser access. You can and should make a backup or your stock ROM, before rooting, using TWRP custom recovery. This gives you an easy way to restore to stock unrooted ROM, if you ever want to. And also gives you an easy "escape hatch" if anything goes wrong while trying to root. There are other tools on this forum for restoring the stock ROM. But best practice (and just plain common sense) is to make a backup in TWRP.
Click to expand...
Click to collapse
---------- Post added at 10:33 AM ---------- Previous post was at 10:24 AM ----------
Phalangioides said:
There's an app called Helium, but there are many complaints that it doesn't fully work. You can try syncing all data to your google account or adb backup.
Click to expand...
Click to collapse
All backup methods are far from perfect, especially before/without root. I'll agree that Helium is probably the best bet for the OP to backup things like game saves.
---------- Post added at 10:36 AM ---------- Previous post was at 10:33 AM ----------
Roger465 said:
It’s amazing how hard it can be to pick up a slightly unfamiliar technology when it’s not the one you're used to… I spent the latter half of my life in IT (Windows), but really struggle with this phone stuff.
Click to expand...
Click to collapse
Stick with it. Every technology has its own lingo and nuances. Even from one Android device to another, there is a learning curve. I've found myself wondering: "WTF is a blob, or Odin" when switching to other Android devices.
With your IT experience, it shouldn't take much to pickup the necessary knowledge.

Thanks guys, kind of you to go to so much trouble to explain for me. Wish I had two phone,s then I could play around messing one up... will read a bit more, then give it a go in a day or two I think. But just to clarify again, can I give myself the rights to remove stock bloatware, while maintaining my familiar Android environment, the apps I use at the moment etc, or do I have to install a custom ROM if I root?
Cheers

Roger465 said:
can I give myself the rights to remove stock bloatware, while maintaining my familiar Android environment, the apps I use at the moment etc, or do I have to install a custom ROM if I root?
Click to expand...
Click to collapse
Yes, the OS will remain the same.
Whether you can remove bloat apps after root is a little complicated to explain. You would normally expect to be able to delete system apps (which bloat apps are) with root. However, for whatever reason, HTC decided to write-protect the system partition, even with root. This means that if you try to delete apps when the phone is booted to OS, (depending on what method you used to delete the apps) you will find they return when the phone is rebooted.
You can flash a kernel mod to disable the write protection, or install a custom kernel. Or you may find the easiest work around (after root) is to use the file manager within TWRP to delete the bloat apps.
---------- Post added at 12:43 PM ---------- Previous post was at 12:11 PM ----------
Vomer's guide is a good one, for unlocking the bootloader, custom recovery and root:
https://forum.xda-developers.com/htc-one-m8/general/vomerguides-m8-bootldr-unlock-s-off-t2800727
It's a bit outdated, so some words of advice:
- Only follow parts 0 and 1 of the guide. The sections after that aren't needed (s-off and SuperCID) for root, and the s-off method no longer works.
- Use an updated version TWRP from what is in the guide. If you are currently on Marshmallow, the current version TWRP 3.2.1.0 should work. Or basically any version 2.8.7 or later. You can get TWRP here: https://dl.twrp.me/m8/
- Similarly, use current version SuperSU 2.82 (use TWRP flashable zip from here): https://forum.xda-developers.com/apps/supersu/stable-2016-09-01supersu-v2-78-release-t3452703
Or alternately, you can use Magisk to root, instead of SuperSU. Honestly, Magisk is really cool, and has lots of features that SuperSU doesn't. So I suggest checking it out: https://forum.xda-developers.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445

redpoint73 said:
Vomer's guide is a good one, for unlocking the bootloader, custom recovery and root
Click to expand...
Click to collapse
Hhmmm, not getting very far with that procedure. Difficulties so far:
- Enable USB debugging in your phone's Developer options - DONE
- Un-check "Fast boot" on your phone by going to Settings -> Battery Manager – NO SUCH OPTION
- Install ADB and Fastboot on your computer - DONE
- Make sure to back up all of your app data using either ADB or HTC Sync, because you will be wiping your phone – JUST PLAYING AROUND WITH CONNECTING TO THE PHONE AT THIS STAGE
- Install the HTC One M8 drivers on your computer (if you have HTC Sync installed, then you already have them) - DONE
Enter Fastboot (bootloader) Mode
Place your device into fastboot mode by plugging in your HTC One to your computer,
then powering it down by holding both the Power and Volume Down buttons until you see the screen below – WHEN I DO THAT, IT JUST TAKES A SCREENSHOT

Roger465 said:
Hhmmm, not getting very far with that procedure. Difficulties so far:
- Un-check "Fast boot" on your phone by going to Settings -> Battery Manager – NO SUCH OPTION
Click to expand...
Click to collapse
It was only available back on 4.4. It was removed in 5.0 and above, no need to worry about it now.
Roger465 said:
Enter Fastboot (bootloader) Mode
Place your device into fastboot mode by plugging in your HTC One to your computer,
then powering it down by holding both the Power and Volume Down buttons until you see the screen below – WHEN I DO THAT, IT JUST TAKES A SCREENSHOT
Click to expand...
Click to collapse
The guide is a bit inaccurate in this one. Turn off your phone, then press power and vol down - you should get into bootloader. Select fastboot and when it gets into fastboot, plug in the usb, it should change to "fastboot usb" - or at least I think it was like this.
My phone refuses to boot up after I turn it off. Have to help it with a soft reset and then hold vol down so it gets into bootloader, so I can't fully confirm.

Roger465 said:
- Un-check "Fast boot" on your phone by going to Settings -> Battery Manager – NO SUCH OPTION
Click to expand...
Click to collapse
As mentioned in the previous response, this doesn't apply anymore. The feature doesn't exist (hasn't since Kitkat) and therefore does not need to be turned off.
Also note, this option is not to be confused with the fastboot/adb interface (virtually the same name, for different things) which is still fully working, and required to unlock the bootloader and flash custom recovery. The power option "Fast boot" was just a feature used by HTC to make the phone turn on faster. It was merely a "deep sleep" trick which was not a true "power down" and would interfere with accessing bootloader/fastboot mode if you tried to it from a "power off" condition (since in fact it wasn't truly powered off).
Again, it's irrelevant now, and you don't need to worry about that step at all.
---------- Post added at 09:14 AM ---------- Previous post was at 09:00 AM ----------
Phalangioides said:
The guide is a bit inaccurate in this one. Turn off your phone, then press power and vol down - you should get into bootloader.
Click to expand...
Click to collapse
Agreed, the guide is a little incorrect on that step, and I hadn't caught that (error in the guide) before. Power+vol down to access bootloader, will only work when the phone is powered off.
To the OP, another method/trick to access bootloader:
1) While the phone is on, reboot the phone by holding down the power button, and select "reboot" (or restart, I forget exactly what it says)
2) Once the screen goes dark to reboot, but before the white HTC logo screen appears, hold down the vol down button. Don't let go until you see the white bootloader screen.
3) If the phone simply restart to OS, you simply got the timing wrong. You either started pressing vol down too late, or let go too early. Just repeat steps 1 and 2 until you get it right.
Another alternative, is to force a reboot by holding power+vol up. Again, once the screen goes dark to reboot, but before the HTC logo screen appears, hold the vol down button only. In this case, you simply let go of the power button, and slide your finger down to the vol down button, and don't let go until the bootloader screen appears. This method is handy to know, since it works in all cases when the phone is powered on, even of the phone is "frozen" or stuck not loading the OS.
Phalangioides said:
Select fastboot and when it gets into fastboot, plug in the usb, it should change to "fastboot usb" - or at least I think it was like this.
Click to expand...
Click to collapse
If the phone is already connected to the PC by USB cable before going to bootloader, it should default to fastboot mode once the bootloader is accessed.
Not sure if it will automatically switch to fastboot mode if you are in bootloader, then plug in the USB cable. But that may well be true (and would make sense).
In either case, if it's not in fastboot mode, simply select "fastboot" by using the vol buttons, and confirm the choice by pressing the power button. You should see "fastboot" highlighted in red near the top of the screen.

Phalangioides said:
Turn off your phone, then press power and vol down - you should get into bootloader. Select fastboot and when it gets into fastboot, plug in the usb, it should change to "fastboot usb" - or at least I think it was like this.
Click to expand...
Click to collapse
Wahay! That worked fine, thanks both. Hope you can appreciate, though, how scary it can be for somebody like me following instructions I don't really understand, when the expected thing doesn't happen – visions of bricks keep coming into my mind
OK, will practice these steps a few times till they’re 2nd nature. I have managed to retrieve my phone identifier thingy though

Roger465 said:
Hope you can appreciate, though, how scary it can be for somebody like me following instructions I don't really understand, when the expected thing doesn't happen – visions of bricks keep coming into my mind
Click to expand...
Click to collapse
Don't worry, you won't brick this device with what you are doing (unlock bootloader, custom recovery & root). In fact, this device is very hard to brick. As long as the screen comes on, it can almost always be recovered.
Worst case, is that something goes wrong, and you can't boot the phone. Maybe you did something wrong, or maybe just some random event that was not fault of yours. And maybe it takes you an (hairpulling) hour to find the answer, and figure out what went wrong (or how to recover from the problem). But that pretty much happens to everyone who mods these devices from time to time. If you work IT, you've been there. Stressful, but hardly ever catastrophic.

Woo hoo! Got my unlock code. Now time for some more studying before I do anything drastic - specifically how to back up.
I think the HTC Sync Manager will handle most of it? My contacts are all on Google anyway... main worry is 2 years' progress on various King games

Roger465 said:
Now time for some more studying before I do anything drastic - specifically how to back up.
I think the HTC Sync Manager will handle most of it? My contacts are all on Google anyway... main worry is 2 years' progress on various King games
Click to expand...
Click to collapse
I don't use HTC Sync, personally. So I really don't know. I typically root my devices pretty soon after getting them, and therefore never had to use any no-root backup solutions (Titanium Backup is my go-to backup app, but requires root). A number of folks around these forums have suggested Helium for backing up app data when no rooted (and it was mentioned before on this thread).

redpoint73 said:
I don't use HTC Sync, personally. So I really don't know. I typically root my devices pretty soon after getting them, and therefore never had to use any no-root backup solutions (Titanium Backup is my go-to backup app, but requires root). A number of folks around these forums have suggested Helium for backing up app data when no rooted (and it was mentioned before on this thread).
Click to expand...
Click to collapse
Yeah... it doesn't fill me with confidence. I'm sure I'd do exactly as you if it was rooted. I'll probably do it with several different backup apps, and hope that one of them will do it

Roger465 said:
Yeah... it doesn't fill me with confidence. I'm sure I'd do exactly as you if it was rooted. I'll probably do it with several different backup apps, and hope that one of them will do it
Click to expand...
Click to collapse
The first unlock bootloader will restore your phone. Cross your finger if the game data has been backed up. :fingers-crossed:

redpoint73 said:
I don't use HTC Sync, personally. So I really don't know. I typically root my devices pretty soon after getting them, and therefore never had to use any no-root backup solutions (Titanium Backup is my go-to backup app, but requires root). A number of folks around these forums have suggested Helium for backing up app data when no rooted (and it was mentioned before on this thread).
Click to expand...
Click to collapse
I don't play games so I can't really confirm all games are same.
On my experience transfering games data from one device to another (for nieces & nephews), the data is stored in internal storage android\data\games folder & android\obb\games folder. I copy these two out and transfer them to new device.
(Also check sdcard android folder)

Roger465 said:
Yeah... it doesn't fill me with confidence. I'm sure I'd do exactly as you if it was rooted. I'll probably do it with several different backup apps, and hope that one of them will do it
Click to expand...
Click to collapse
I agree with the approach, make different backups and hope one or more works properly. Games and other apps don't all save data the same way, so no single approach will work in all cases.

Me again, sorry… shortly after that post, I dropped the thing and broke the screen. For one reason or another, I ended up getting a Samsung S6, which I’m quite happy with.
But I want to use the HTC as a spare/emergency phone – trouble is I can’t remember what I’ve done to it, apart from installing something which was recommended as part of my attempted rooting process.
When I switch it on I get the screen below – but no matter which option I select, it just seems to either switch it off or loop back to this screen.
I didn’t go any further than install whatever software it was that gives me this boot menu screen.
I’m no longer interested in rooting it etc – just went to restore it to factory settings and leave it.
Can anybody tell me how please…?
Thanks

Roger465 said:
I can’t remember what I’ve done to it, apart from installing something which was recommended as part of my attempted rooting process.
Click to expand...
Click to collapse
Obviously, if you don't know what you did, it's hard for us to figure out as well.
The "LOCKED" banner at the top of the bootloader screen means the bootloader was never unlocked. So really, no actual mods were done to the phone by you.
All I can think, the "something" what you installed was possibly the Helium app (recommended by another user back up on this thread) which can be used to backup/restore your app data.
Roger465 said:
I didn’t go any further than install whatever software it was that gives me this boot menu screen.
Click to expand...
Click to collapse
I don't know what you're trying to say here. You'll need to be more specific (at least try) than "whatever software". Did you flash something to the phone? Or only installed something to your PC (drivers, fastboot, etc.).
We need to properly understood what you've done, before we can assist further.

redpoint73 said:
Obviously, if you don't know what you did, it's hard for us to figure out as well.
The "LOCKED" banner at the top of the bootloader screen means the bootloader was never unlocked. So really, no actual mods were done to the phone by you.
All I can think, the "something" what you installed was possibly the Helium app (recommended by another user back up on this thread) which can be used to backup/restore your app data.
I don't know what you're trying to say here. You'll need to be more specific (at least try) than "whatever software". Did you flash something to the phone? Or only installed something to your PC (drivers, fastboot, etc.).
We need to properly understood what you've done, before we can assist further.
Click to expand...
Click to collapse
Yeah… sorry, I’m aware how unhelpful my post is. Unfortunately, it was a while ago now, life went tits up for quite a while, and the phone lay in a drawer, being a very low priority. I used to take it out occasionally and charge it up – it started normally.
The other day, I realised I hadn’t charged it in many months, so took it out, and sure enough it was completely dead – so I plugged it in, and it came up with the screen as posted. I let it charge for a couple of hours, then rebooted, and it came up that way again. No matter which option I select from the menu, it either just shuts down, or reboots to that screen.
I’m virtually certain I didn’t do anything other than enable the mode which lets you get to that boot screen, and that I didn’t get as far as flashing the phone or anything. Don't think I installed Helium - if I did, I didn't actually use it.
So it may just be that the phone has died from being left flat for so long… is that likely do you think?
Thanks and sorry again for the lack of info – I completely understand if you can’t help!

Roger465 said:
I’m virtually certain I didn’t do anything other than enable the mode which lets you get to that boot screen, and that I didn’t get as far as flashing the phone or anything.
Click to expand...
Click to collapse
Okay, so it was somewhat confusing, as you said previously (twice) that you "installed" something. But I think you are just confused, thinking that installing something is necessary to get to the bootloader screen. Which it isn't, that screen is part of the bootloader, without which your device would be a paperweight. It will sometimes default to this screen by virtually no action of yours (except powering it on) in cases when the Android Operating System (OS) is missing or damaged. Or you can simply access the bootloader screen by holding the button combo power+vol down.
Roger465 said:
So it may just be that the phone has died from being left flat for so long… is that likely do you think?
Click to expand...
Click to collapse
We've seen it a number of times, actually. The OS was probably corrupted or damaged by being powered off (battery dead) for so long. This condition is over recoverable, as long as the phone can power on, and you can get to bootloader (which you can).
You can restore the OS with the RUU (ROM Update Utility) tool. You can get the RUU, and instruction how to flash it from here:
https://forum.xda-developers.com/showpost.php?p=64926626&postcount=6
Note: there is no need to lock the bootloader as the first part of the instructions say (your bootloader is still locked).

Confusion about flashing roms on A/B

Hi all
I come from the Oneplus one where flashing has been pretty straight forward. Now I am in the possession of a Pixel 2 XL and I would like to flash some roms on it. I have read many threads on flashing on the Pixel 2 xl and it always seems to have some caveats involved. I have tried to search the internet for a good tutorial but I have not discovered one yet. In advance, I am sorry if I missed some good resource on this.
So, here is my situation: I am currently on the latest patch (February 2019) and let's assume I would want to flash HavocOS. My bootloader is unlocked and I know thaf I either have to flash TWRP or only temporarily boot into TWRP. Usually, here I would flash the Rom, gapps, and magisk. For updates I would simply dirtyflash the newest rom version. As far as I have gathered, flashing the Pixel is not that straightforward.
Does TWRP flash automatically both A and B?
Do I need to flash the rom twice? Once A and once B? Or simply flash it once?
Do I need to extract things such as vendor, radio, bootloader etc and flash that once/twice? Only for the first time or for every (dirty)flash?
I would love to learn the standard procedure on flashing the Pixel 2 XL.
Again, I am sorry if I missed some good resource on this.
Thank you for your time and your help!

Welcome to the 2 XL family.
The 2 XL is a fickle beast, which you will soon find out
There is a link for upgrading/updating the 2XL in my sig, but as usual there are many ways to skin the proverbial cat.
As far as slots; I have never manually selected a slot for ANYTHING. Not TWRP, not cust Roms, not stock Roms, not kernels, not Magisk.
Whenever I flash something, the slots are always automatically chosen by whatever I'm flashing.
I know that you CAN manually select slots, but in all the time and the hundreds of Roms, kernels, Magisk versions I've flashed, I have never manually selected a slot.
Again, there are many ways to do nearly everything related to the 2 XL, and my way certainly is not the only or absolute best method, but the step by step in my sig has always, without fail, been successfully followed by myself and many other for flashing cust kernels, cust Roms, updating stock images, rooting, fastbooting, etc.
If you ever get into a sticky situation, hit up some of the 2 XL regulars who have a wealth of knowledge individually and can fix anything collectively.
@Badger50, @clothednblack, @Pkt_Lnt, @post_mortem, @simplepinoi177, @TonikJDK just to name a few.

Thank you for your insightful comment! Very helpful!
I went through your signature and got a lot of good information.
However, I still have some questions regarding about vendor, boot, radio etc.
I found this comment in the Havoc ROM thread: https://forum.xda-developers.com/showpost.php?p=78842872&postcount=1800
Are you usually dirty flashing that way?
Thank you so much for your help!

hascherpur said:
Hi all
I come from the Oneplus one where flashing has been pretty straight forward. Now I am in the possession of a Pixel 2 XL and I would like to flash some roms on it. I have read many threads on flashing on the Pixel 2 xl and it always seems to have some caveats involved. I have tried to search the internet for a good tutorial but I have not discovered one yet. In advance, I am sorry if I missed some good resource on this.
So, here is my situation: I am currently on the latest patch (February 2019) and let's assume I would want to flash HavocOS. My bootloader is unlocked and I know thaf I either have to flash TWRP or only temporarily boot into TWRP. Usually, here I would flash the Rom, gapps, and magisk. For updates I would simply dirtyflash the newest rom version. As far as I have gathered, flashing the Pixel is not that straightforward.
Does TWRP flash automatically both A and B?
Do I need to flash the rom twice? Once A and once B? Or simply flash it once?
Do I need to extract things such as vendor, radio, bootloader etc and flash that once/twice? Only for the first time or for every (dirty)flash?
I would love to learn the standard procedure on flashing the Pixel 2 XL.
Again, I am sorry if I missed some good resource on this.
Thank you for your time and your help!
Click to expand...
Click to collapse
Thank you @Az Biker! You are the best! You don't know how flattered I am that you even kept me in mind, let alone be among that great list...I am truly humbled...
So, hascherpur, I'll answer a bit of your questions, then I'll offer you some general advice when starting up with this Pixel 2 XL (taimen) as well as some dire tips if/when you get yourself in trouble (as Az Biker had alluded, it seems with this device, it is rather "inevitable" :good: )...
TWRP (and most other flashing installation files/process [ROMs, Magisk, etc.]) actually consider and keep in mind the multi-slot possbility and have made it that, if it's called for, it will automatically patch/boot/load either/both/individual slot. You'll see many and mmaannyy others go about manually/forcibly "set[ting]" and choosing specific slots, but I, like Az Biker, in my (roughly) 16 months of using this device have never, ever found a reason to -- and, for better or worse, I've broken my taimen and my gf's walleye countless times and managed to save/recover it but completely got it bricked twice.
The time you need to extract those (bootloader, radio, vendor, etc.) is when you're updating or reparing/recovering your device. A note about that though: if you wish to manually update our device (monthly; for the security updates), the absolute best way to go about it is to download the Full Factory image direct from the Google Developer's website, and extract the files within the .zip (usually these bootloader, radio, vendor, and others totalling usually 9-ish files) into the folder that has adb.exe and fastboot.exe, modify/edit the "flash-all.bat" file/script (flash-all.sh depending on your OS) and remove the "-w" (unless you wish to "w"ipe your internal), and then run that flash-all file. Because this manner of updating essentially re-installs the /system and /vendor folders and partitions, this would actually be more of a "clean" flashing than the other methods; downloading the OTA (not Full Factory) image and manually (via adb) updating and/or modifying your device so it will take an OTA update -- which is it's own hairpulling and (imo) unnecessary process -- these methods should be considered "dirty" flashing/updating, if anything.
I'm unsure how HavocOS ROM updates and if it needs to be done within its own environment or in the recovery, but I imagine much of what I just said would still apply, at least in some manner.
Okay, some general info you would find helpful and would (hopefully) keep you from falling into some of the "pitfalls" that we've all run into and have told ourselves "...if I had only known beforehand...". There is the fact that, for all Pixels -- and I'm pretty sure any multi-slot device -- there is no more recovery partition! It now resides in & with the boot partition/image. This has thrown so many new users of Pixel phones for a loop...they're usually attempting to "flash to recovery" for 24 hours before finding this out :silly:. Then there is ALL the issues you'll run into with adb, fastboot, and platform-tools in general; When you get issues when using adb and/or fastboot, you're initial instincts is going to lead you into thinking something is wrong with the image, device, and/or commands -- and with this/our phone, many times that is not the case (believe it or not, it'll put up a flashing-type error, but it's actually the USB cord?!)! Az Biker has the best troubleshooting guide in his signature, and it holds advice that usually gets things working 90% after having issues -- some general tips to keep in mind is make sure you UPDATE the platform tools and sometimes, for some reason, you have to run the same commands/process 4-5+ times before it "...works all of a sudden, this time...!" But, basically (as Google is genius in this), as long as you have access to Bootloader Mode, then there's always hope! I've gone as far as re-formatting partitions, changing the partition type, changing the size of the partition, and even manually flashing 12+ image files after forcing the partition size to change for those image files, and I've been able to come back from it because of being able to have access via Bootloader Mode.
Now, being able to unlock the bootloader and have a custom recovery, especially considering you plan on flashing custom ROMs and/or kernels and such, IT IS BEST THAT YOU MAKE A BACKUP (NANDROID IS BEST)! I know that this isn't exclusive advice for the Pixel 2 XL, but it still bears reminding; but here's some taimen specific advice -- keep in mind that many backup processes (TWRP specifically) does not (normally*) backup the data in your /internalsd (which includes your Download, Music, Photos folders)! (*i say "normally" because there is a convoluted method I've found that actually does backup the internal sd which I do every month, which I could walk you through if you are interested...). But I believe it's the best backup method because it at least backs up the system, boot, and data partitions -- note: you don't have to replace and install the custom recovery in order to utilize it; there is always temporarily booting the twrp "image" and running it off that -- but there is also TB and the other myriad ways to backup as you see fit (I'm completely unfamiliar with HavocOS, but there might even be a backup method via its environment). The key thing is: that you make backups!
And, lastly, some specific advice for when you run into issues... Re-installing/Re-flashing the Full Factory image is always a great way to fix a lot of the issues out there -- I still remember the days of my Galaxy S5 and Motorola Droids where "flashing" would wreck and wipe all data and customizations, so I love how Google made it so that's not the case with the Pixels -- but if you find that it hasn't resolved the issue, using Deuce's script (that can be found HERE) has saved countless many in repairing and recovering our devices. One of the greatest things about it is that it manually and individually flashes each and every image file to BOTH slots! Thereby covering a lot of "little bases" that a standard flash-all script doesn't do -- the only caveat is that you'll have to additionally extract all 15+ image files from the image .zip file (that resides within the Full Factory .zip file). One last recovery bit of advice, running the command "fastboot getvar all" will provide a great deal of pertinent information about the device, to say the least! It'll be good if you wish to check and to include when requesting help...
My deepest apologies for making this as long as it is; for those who know me, sometimes I can't help myself. Well, there's really that many crazy things that would be so helpful to know at the beginning with this device as well as I type very fast and fluently (kind of as fast as I talk), so I get away from myself...In any case, thanks for reading this far, if anything, and my sincerest apologies...
Again, I'm very happy to help and so glad the Great Az Biker had thought of me to include. This is a wonderful, great device and I don't want any other! But, as with all great things and loves, it will also have its "hair-pulling" headaches...so, just take your time and read and re-read, keep some of these things in mind, and good luck to ya!

Well @simplepinoi177: How am I even supposed to answer to your post? This is an incredible resource (maybe even warrants a sticky somewhere) and I am very grateful for all the details you just shared. Thank you so much. I did not expect such a warm welcome!
I have one last question: as it turns out, I was using a Taimen before (for a few months), but did not really bother using roms. In the end this proved to be really helpful as my USB port broke. I could still charge the phone, but I was unable to access the phone through cable (no bootloader, no adb, nothing). Luckily the RMA process gave me a completely new phone.
Now I wonder: if my phone's USB port breaks, I then need to RMA it and it has a rom on it, how could I restore it to a stock-like situation? I got a new device even though the bootloader was unlocked. I guess I could flash the stock image through TWRP somehow. How would I remove TWRP without a cable though?

simplepinoi177 said:
.....
.
.
.....But, as with all great things and loves, it will also have its "hair-pulling" headaches...so, just take your time and read and re-read, keep some of these things in mind, and good luck to ya!
Click to expand...
Click to collapse
Tons of solid advice, willingness to help, and a lot of experience.
^^^^^This is why I included you in the list of great resources!

hascherpur said:
Well @simplepinoi177: How am I even supposed to answer to your post? This is an incredible resource (maybe even warrants a sticky somewhere) and I am very grateful for all the details you just shared. Thank you so much. I did not expect such a warm welcome!
I have one last question: as it turns out, I was using a Taimen before (for a few months), but did not really bother using roms. In the end this proved to be really helpful as my USB port broke. I could still charge the phone, but I was unable to access the phone through cable (no bootloader, no adb, nothing). Luckily the RMA process gave me a completely new phone.
Now I wonder: if my phone's USB port breaks, I then need to RMA it and it has a rom on it, how could I restore it to a stock-like situation? I got a new device even though the bootloader was unlocked. I guess I could flash the stock image through TWRP somehow. How would I remove TWRP without a cable though?
Click to expand...
Click to collapse
Thank you hascherpur, I appreciate the sentiment. But, as I mentioned, as much as it helps you, it helps the helpers here as well. Anyone whose worked on our taimen and walleye can attest to those few things that would save soooooo many people if they just knew these small insignificant-seeming tidbits...
I am actually in this particular situation currently myself. Me (and this other fellow) got our devices (my gf's walleye to be exact) bricked where fastboot does not recognize and detect the USB plug, even though it is charging and just because of this fact, there's nothing that can be done and only a RMA is in order... But the key difference is that my custom recovery also somehow broke. That's why, at it's base purpose, a custom recovery is meant to replace and enhance your repair/recovery options -- so you can have it in dire situations and boot it up and utilize it if needed. If my TWRP was still accessible, I would more than have a chance to repair the device.
But to answer your specific question, I imagine a data wipe/erase from either stock or custom recovery would be in order. And, depending on how particularly broken the USB port is, you might still consider and try a USB-C flash drive and attempt the OTG enabled feature. If that could still work, then I've gotten the idea that attempting to install the system via OTA update installation .zip might be able to help -- but I would have my doubts because, like I kind of stated in my last post, that's more of a "dirty flash" and I wonder how well an not-so-complete OTA update can work and establish itself when its base /system and /data partition is wiped and essentially just empty space...But, also, if even a flash drive can be read, then you should be able to use adb to move essential flashing files to the device and utilize fastboot to make repairs and re-flash (i'm unsure if fastboot can manage this off of a flash drive; i'm not even sure it has OTG capabilities...). If, at that situation, the one resource I mentioned, Deuce's script, would be great as it will flash all pertinent and important stuff if, for some reason, the flash-all can't get passed flashing certain portions like bootloader or vendor.
So that's the ideas that come to my mind as possibilities that might work...hope this helps...

simplepinoi177 said:
Thank you hascherpur, I appreciate the sentiment. But, as I mentioned, as much as it helps you, it helps the helpers here as well. Anyone whose worked on our taimen and walleye can attest to those few things that would save soooooo many people if they just knew these small insignificant-seeming tidbits...
I am actually in this particular situation currently myself. Me (and this other fellow) got our devices (my gf's walleye to be exact) bricked where fastboot does not recognize and detect the USB plug, even though it is charging and just because of this fact, there's nothing that can be done and only a RMA is in order... But the key difference is that my custom recovery also somehow broke. That's why, at it's base purpose, a custom recovery is meant to replace and enhance your repair/recovery options -- so you can have it in dire situations and boot it up and utilize it if needed. If my TWRP was still accessible, I would more than have a chance to repair the device.
But to answer your specific question, I imagine a data wipe/erase from either stock or custom recovery would be in order. And, depending on how particularly broken the USB port is, you might still consider and try a USB-C flash drive and attempt the OTG enabled feature. If that could still work, then I've gotten the idea that attempting to install the system via OTA update installation .zip might be able to help -- but I would have my doubts because, like I kind of stated in my last post, that's more of a "dirty flash" and I wonder how well an not-so-complete OTA update can work and establish itself when its base /system and /data partition is wiped and essentially just empty space...But, also, if even a flash drive can be read, then you should be able to use adb to move essential flashing files to the device and utilize fastboot to make repairs and re-flash (i'm unsure if fastboot can manage this off of a flash drive; i'm not even sure it has OTG capabilities...). If, at that situation, the one resource I mentioned, Deuce's script, would be great as it will flash all pertinent and important stuff if, for some reason, the flash-all can't get passed flashing certain portions like bootloader or vendor.
So that's the ideas that come to my mind as possibilities that might work...hope this helps...
Click to expand...
Click to collapse
Thank you simplepinoi177! Very helpful. I have also seen that it is possible to access adb via wifi. But I doubt that I am able to use fastboot via wifi.
In any case, I am deliberating what the best course of action at the moment is. It seems that the Pixel 2 XL's usb port is a common point of failure. Therefore, I am trying to make sure that I leave my phone in a state, where I can easily revert it into an RMA-able state. I think with TWRP installed, I could get the stock image easily installed. I am still not sure how to remove TWRP without a cable, should the USB port break.

hascherpur said:
Thank you simplepinoi177! Very helpful. I have also seen that it is possible to access adb via wifi. But I doubt that I am able to use fastboot via wifi.
In any case, I am deliberating what the best course of action at the moment is. It seems that the Pixel 2 XL's usb port is a common point of failure. Therefore, I am trying to make sure that I leave my phone in a state, where I can easily revert it into an RMA-able state. I think with TWRP installed, I could get the stock image easily installed. I am still not sure how to remove TWRP without a cable, should the USB port break.
Click to expand...
Click to collapse
To remove twrp without a cable, simply put the stock boot.img on your internal storage, and flash it with twrp. After you reboot, twrp will be gone.
Here's the February boot.img if your interested :good:
https://drive.google.com/file/d/1khLnNH7emt38sDsD7UmKX3HJG3lhxdXQ/view?usp=drivesdk

Badger50 said:
To remove twrp without a cable, simply put the stock boot.img on your internal storage, and flash it with twrp. After you reboot, twrp will be gone.
Here's the February boot.img if your interested :good:
https://drive.google.com/file/d/1khLnNH7emt38sDsD7UmKX3HJG3lhxdXQ/view?usp=drivesdk
Click to expand...
Click to collapse
Oh, thanks! I guess I am all set . Thanks to everyone for the very helpful answers!

Badger50 said:
To remove twrp without a cable, simply put the stock boot.img on your internal storage, and flash it with twrp. After you reboot, twrp will be gone.
Here's the February boot.img if your interested :good:
https://drive.google.com/file/d/1khLnNH7emt38sDsD7UmKX3HJG3lhxdXQ/view?usp=drivesdk
Click to expand...
Click to collapse
genius idea! I was actually asking myself that question, and this is a great set up. But, usually, if I'm in so much trouble that I need to return it to stock recovery that urgently, the device most likely is probably so messed up that it probably wouldn't be able to read/find the boot.img I would keep in the sdcard storage...

simplepinoi177 said:
genius idea! I was actually asking myself that question, and this is a great set up. But, usually, if I'm in so much trouble that I need to return it to stock recovery that urgently, the device most likely is probably so messed up that it probably wouldn't be able to read/find the boot.img I would keep in the sdcard storage...
Click to expand...
Click to collapse
You gotta approach this stuff like the first part of your name my friend. Take it from an old guy...."Simple" is good! :laugh::good:

Deuces script will synch your a and b sides so you don't need to worry about them getting weird.

madscribblerz said:
Deuces script will synch your a and b sides so you don't need to worry about them getting weird.
Click to expand...
Click to collapse
That is precisely why I use it every month.

General help with bootloader & flashing (coming from Sony phones)

Any help is greatly appreciated, I have no experience with Google phones, I was years into Sony.
I have just bought a Pixel 2 XL from a local shop in Greece, and of course, I want to root it and be able to install custom roms etc.
I have a few questions that I am searching everywhere recently and I would really appreciate if someone can make it clear to me:
1) I have read that you have to buy your phone from Google so you are able to unlock it? Can someone explain this to me? (My phone is not a specific carrier) How do I know if I am able to unlock my bootloader?
2)I have flashed roms and kernels in the past on my Sony phones, however I haven't really messed with the bootloader other than just unlocking it in the beginning. So now on the Pixel 2 XL I am reading so much about the unlock_critical vs the normal unlock, and I can admit I cannot understand the difference. Why does someone want to flash a bootloader? ( I do not understand what does "flash a bootloader" mean)
What I want to be able to do is flash custom roms, flash factory images to revert back to stock whenever I want, flash custom kernel, flash stock kernel, make a nandroid backup with twrp and restore a nandroid backup with twrp. That is all I want to be able to do without facing any errors with the bootloader,so do I need the unlock_critical ? And why?
3)If I unlock the bootloader with any of the two ways, am I able to re-lock it like nothing has happened? For example if the screen has dead pixels for some reason and I want to send it back for warranty but the bootloader is unlocked, can I lock it without it being logged? Or once unlocked, there is no going back to the warranty by re-locking? On many Sony phones we could do that.
4)If I unlock the bootloader and install TWRP I read that I will not be able to receive official updates from settings any more (OTA):
"NOTE #1: If you have mounted /system as rw at any point (like in TWRP), you must upgrade using the factory image method. OTAs will fail because they cannot verify the integrity of the disk since its verity data has been changed."
My question is, if I flash a stock image, does that get fixed? ( so if I flash 8.1.0 stock manually, will I be able to get an official update e.g. 9.0.0 from settings?)
Or if I just grab the stock boot.img of my current version of android and flash it with fastboot, then will I be able to get official updates from settings normally again?
5)Can I do the following on this order? :
Enable USB Debugging and OEM Unlocking
Unlock the bootloader (either critical or normal, whatever works)
Boot into Fastboot
Boot the twrp image from fastboot to the device
Flash the twrp zip to the phone to install TWRP
Flash the magisk zip so I root the device
Reboot and everything works? (Or do I need a custom kernel for TWRP or Magisk to work?)
Is there any issue you see with the above plan of mine?
6) Before I tweak my device in any way, is it okay if I update the device fully? So can I install any update available (OTA) and then unlock the bootloader and root etc? Or do I have to be on a specific version and not on the latest?
7)I have read something about 2 different slots on some flashing forums here, slot a and slot b, but it is not clear to me what that is. Does anyone know what that is? At which point may I face this?
Thank you very much.

A quick and not complete response to get you going
Plan 5 seems solid, unlock the bootloader to allow custom stuff. At boot you will get a warning screen to let you know.
I forgot if I only unlocked the bootloader or also the critical, try it etc.
Personally I never had to tinker with the A/B slots, within TWRP you can choose which to use.
Before Magisk, I used to flash another recovery like cwm or twrp but it is not required. You must however boot to twrp.img to flash the magisk zip.
As far as I know it is indeed the altering of the /system folder that denies future OTA (when using factory image). A manual flash (of future OTA) is easy but may require altering (removing) a switch command in the install.bat file to remove the -w (wipe).
As to the custom kernels, I never noticed the need and am running the latest v10 image with only Magisk flashed to get root.
My main goal is to get rid of ads. I use AdAway.
To get that to work in v10 you need to enable systemless host module im the Magisk manager app (reboot after).
A final feedback; when you get to sideload and need to get to recovery you may get the screen 'no command' or so; press volume-up and click power or power->click volume.
Let us know if you worked it etc!

arismelachrinos said:
Any help is greatly appreciated, I have no experience with Google phones, I was years into Sony.
I have just bought a Pixel 2 XL from a local shop in Greece, and of course, I want to root it and be able to install custom roms etc.
I have a few questions that I am searching everywhere recently and I would really appreciate if someone can make it clear to me:
1) I have read that you have to buy your phone from Google so you are able to unlock it? Can someone explain this to me? (My phone is not a specific carrier) How do I know if I am able to unlock my bootloader?
2)I have flashed roms and kernels in the past on my Sony phones, however I haven't really messed with the bootloader other than just unlocking it in the beginning. So now on the Pixel 2 XL I am reading so much about the unlock_critical vs the normal unlock, and I can admit I cannot understand the difference. Why does someone want to flash a bootloader? ( I do not understand what does "flash a bootloader" mean)
What I want to be able to do is flash custom roms, flash factory images to revert back to stock whenever I want, flash custom kernel, flash stock kernel, make a nandroid backup with twrp and restore a nandroid backup with twrp. That is all I want to be able to do without facing any errors with the bootloader,so do I need the unlock_critical ? And why?
3)If I unlock the bootloader with any of the two ways, am I able to re-lock it like nothing has happened? For example if the screen has dead pixels for some reason and I want to send it back for warranty but the bootloader is unlocked, can I lock it without it being logged? Or once unlocked, there is no going back to the warranty by re-locking? On many Sony phones we could do that.
4)If I unlock the bootloader and install TWRP I read that I will not be able to receive official updates from settings any more (OTA):
"NOTE #1: If you have mounted /system as rw at any point (like in TWRP), you must upgrade using the factory image method. OTAs will fail because they cannot verify the integrity of the disk since its verity data has been changed."
My question is, if I flash a stock image, does that get fixed? ( so if I flash 8.1.0 stock manually, will I be able to get an official update e.g. 9.0.0 from settings?)
Or if I just grab the stock boot.img of my current version of android and flash it with fastboot, then will I be able to get official updates from settings normally again?
5)Can I do the following on this order? :
Enable USB Debugging and OEM Unlocking
Unlock the bootloader (either critical or normal, whatever works)
Boot into Fastboot
Boot the twrp image from fastboot to the device
Flash the twrp zip to the phone to install TWRP
Flash the magisk zip so I root the device
Reboot and everything works? (Or do I need a custom kernel for TWRP or Magisk to work?)
Is there any issue you see with the above plan of mine?
6) Before I tweak my device in any way, is it okay if I update the device fully? So can I install any update available (OTA) and then unlock the bootloader and root etc? Or do I have to be on a specific version and not on the latest?
7)I have read something about 2 different slots on some flashing forums here, slot a and slot b, but it is not clear to me what that is. Does anyone know what that is? At which point may I face this?
Thank you very much.
Click to expand...
Click to collapse
1) The reason for this is Google had an exclusivity contract to sell through the US cellular company, Verizon; much like the original Apple iPhone did (at first) with AT&T. And, for reasons that are most likely stupid, foolish, and unconvincing in its justifications, Verizon locks their device's bootloaders. So, not that it's "locked" or "unlocked" in terms of carriers, but more-so whether a device is "locked bootloader" or unlockable because it was purchased from Google (or elsewhere, but at least originally Google) and not from Verizon. If you're wondering further, getting it from Verizon would allow Verizon subscribers and customers to be able to "lease" and pay the Pixel off in increments with their usual cell phone bill; but it's not all too exclusive because Google offers to lease if you purchase from them also! The only caveat is you have to pass a credit check when leasing from Google; but, then again, you have to pass a credit check when signing up for a Verizon cell plan as well!
2) So, with my limited understanding between the difference between just a regular "unlock" and an "unlock_critical" is that it might be that a regular unlock allows you to get a R/W access (root access) to the various vital partitions (i.e. system, data [not to be confused with userdata], even boot to a degree) while unlock_critical allows you to straight modify and replace partitions (i.e. what would've been the recovery partition [but now there's no such thing and recovery just resides in the boot partition], the whole system & data partition to have/run custom ROMs, bootloading screen, etc.). But it all is rather convoluted that Google probably agreed and, so you can/should be aware, they updated things within the past few months (I'm guessing June or July) where they rid the need to "unlock_critical" and bootloaders that are newer than a certain point/month no longer needs that fastboot command to unlock the bootloader and everything else in order to flash custom anythings...
3) Okay, so here's a very tricky thing to this.... Technically, yes you can relock the bootloader as well as there have been many who have successfully done so; BUT there are so many more that have COMPLETELY and permanently bricked their device attempting to do so and most (if not all) the experts here would advise anyone to just leave well enough alone. But, if it is insisted and must be, the way to do it is to remove all Magisk modules (because, for whatever reason, these modules can survive a complete flashing of a Full Factory stock image), run a Full Factory image where the flash-all command is left intact (meaning “-w” is unedited; I’ll go more into this later), running it through the initial set up process, then (for good measure, this step might not be at all absolutely necessary) switch slots and run the flash-all command on the other slot, running the initial set up process again, then rebooting to Bootloader Mode and running the fastboot locking command, then unticking (if wished and insisted) unticking the OEM unlocking. Again, a word of warning, that so many have relocked the bootloader and unticked the OEM unlocking which allows the unlocking of the bootloader, then find that their device goes into a bootloop; and since they had just locked the bootloader in 2/all different ways, it leaves rescuing the device with all but the fewest options – usually because it’s forgotten in one way or another returning all of the device back to stock.
If anything, what has been said around these forums is that, if returning to Google, there hasn’t been an (proven) instance that Google refused to repair/replace it because it had its bootloader unlocked. But it’s usually for that fear or re-selling the device in which this is usually sought; but in most (if not all) cases (the experts here figure), having the bootloader unlocked would be refused or looked down upon.
4) So, most of what you assumed here is correct; but may be a bit misguided due to not knowing some things – which, of course, can be expected since you had just said you just moved to this device from a totally different manufacturer (Sony). If you are rooted (Magisk), there is absolutely no way you can update via the regular System Update from an OTA from within the Settings in the OS. And even having just an unlocked bootloader will cause OTAs to not work -- but there are conflicting reports stating differently, but I, personally, am under the understanding that even at that point you cannot.
But here’s the key thing; there really isn’t any reason to install updates by download and using OTAs anyways. Most (if not all) the experts here actually forego the OTAs and merely download the Full Factory stock images from Google’s Developers website and flash those. Here’s the reason; in the “olden days”, flashing a stock Full Factory image would erase absolutely everything and return the device to a complete factory state. But Google, in their “infinite wisdom”, allowed it to be possible to flash this but still withhold and save/keep all of one’s apps, settings, and data – essentially leaving both device data and userdata untouched! This is achieved by simply editing a batch file called “flash-all.bat” (or “flash-all.sh” for Linux and MacOS) and removing the 3 characters “-w” (3rd character would be a space “character”) from within its code. In this manner, OTAs can be considered a “dirty flash” because, while a Full Factory will completely overwrite (I could be wrong, but I believe it erases and formats it) the system, radio, bootloader, boot, etc., which would/should take care of any erroneous bugs or glitches, while OTA’s do not necessarily do this and just “modifies” the existing data; and therefore bugs and glitches may still remain being more on the root of things and/or OTAs would just modify “on top” or elsewhere where those glitches may reside.
And in either/both cases, one would still be required to reflash/reinstall everything root.
But, if insisted, there are multiple methods to achieve a state where you can run an OTA; either downloading an OTA image from Google and manually flashing it (“sideloading”), or unrooting temporarily to be able to use & download the regular System Updater (can be found HERE : https://github.com/topjohnwu/Magisk/blob/master/docs/tutorials.md#ota-installation under the “Devices with A/B Partitions” which is my preferred method if I was to do this sort of thing, but I have never done this so I’m unsure if it even is successful in our device). I even wrote out an in-depth and step-by-step guide, but it is rather convoluted and was written in the beginnings of our taimen and there are most likely more updated methods now; but if you want to check it out, you can HERE.
But, to answer your questions directly; No, flashing the stock image will not allow you to user the stock System Updater; although there are conflicting reports, I am under the impression that anything other than a locked bootloader will allow the stock System Updater to work.
5)More correctly, you boot into “Bootloader Mode” to be able to use the “fastboot” commands. And no, you do not need to permanently flash a custom recovery (TWRP), a custom kernel, or anything else to achieve root – although I do highly recommend it – as you can temporarily boot into TWRP (by downloading the TWRP image file (*.img) and install Magisk in that manner – I do not suggest you root/install Magisk using the app. Other people have had success, but many (most?) have issues that you wouldn’t run into if you installed it via TWRP – but here’s a key thing; no matter what you intend to flash and install, unless you need to have root for it to already be installed, you should always flash Magisk last. Moreso, as the great Az Biker of ‘round thes’ parts greatly suggests, you should even reboot to bootloader after each and every flash separately. Explanation is, for whatever reason and even though many claim to be able to “detect” and modify their flash for an already modified boot and dtbo (where modifications must happen for root access), most don’t play well with Magisk and Magisk must modify the boot and dtbo after all other modifications or else problems can arise (or at least it has for me).
Just keep these things in mind, but, for the most part, your “order” of things will do well enough. Again, just keep in mind that if you are going to install a custom recovery or kernel, try to do that before Magisk as well as if you can avoid it, don’t use the Magisk app to install or manually flash any boot.img if you can help it.
6)No, you don’t have to stick to a specific version; it might even be suggested to update it stock before doing anything. BUT (of course there is a caveat), consider this; many things (especially anything root and specifically TWRP) aren’t really “playing nice” with Android Q/10; so, if you update and go to the most up to date, but don’t wish to run into those glitches/bugs and wish to “hold off” (like I am, actually and for the same reasoning), then of course you should only go up to August (I believe that was the last before the upgrade to Q/10) Full Factory.
7) There are many great resources on the information on having the 2 different slots; I apologize if I can’t recall where I even saw them – other members (maybe an RC or Mod even) input a URL to read and I can’t for the life of me recall where it possibly could be. But, for the most part, you would really only run into identifying and manually changing to a specific one if you were attempting to rescue or deeply modify your device; I can say that me and the great @Az Biker have never felt the necessity to manually change or choose a certain, specific slot. And, my guess, is that, because the coding and flashing output when running the Full Factory states something about “system_other” or a “system_b”, but while the main system can be close to 3GB, the system_other is closer to 300MB, and that boot, dtbo, vendor, and something called lafb has a “_b” partition, I’m thinking it’s something as a safety or backup, maybe something like what used to be in old laptops a sort of RAM to help load things up faster. In any case, it seems that going from one to the other, a to b or vice-versa, doesn’t seem to be too key or much of a hassle, so….take that for what you will.
Alright…hopefully I was able to answer all your inquiries. And, if you have any more, please feel free to ask them…that’s what we’re all about here. And I know I can run on and get wordy, so thank you for bearing with me with all of this.
I mean, it’s really good to have a user/member who really does their research, reading, and due diligence before getting into their new device; there are so many instances here and in my own experience where the “…if I only knew that beforehand…” would be supremely helpful, and supremely easier on everyone else! So that’s to be commended and reinforced…!
Hope this helps and welcome to your Pixel and this taimen forum!

I really cannot thank you enough for your time. I truly appreciate it very much.
1) Very clear.
2) Do you happen to have a link or do you know how to check if my phone supports unlock_critical? How can I check if I have that newer bootloader? Or do you remember where did you learn this?
3) Thank you so much about that. Very clear aand you just saved my phone
4) Very clear.
5) Thank you for the info! Interesting, I was searching on how to root the device running Android 10 (I have fully updated and I really am not going back to Android 9 ), and I saw that you have to patch your boot.img with the Magisk app, and then flash it with fastboot. So first you get the factory image from google and you extract the boot.img and insert it to the phone. Then you load it into Magisk app and patch it. Then moving the patched to the PC, booting to bootloader and flash it on boot partition. This is the way I saw on how to get root working fine with Android 10, not sure if it is the best method or the worst.
6) What do you mean with "go up to August"? Do you mean that the "oldest" image I can flash is "9.0.0 (PQ3A.190801.002, Aug 2019)"? So one cannot go back to 8.0.0 and Google has done something to prevent us from doing that? Also, if I wanted to go back to that August image or any "compatible", the procedure is just to run the flash-all.bat file of that image?
I used to experement a lot with custom roms, custom kernels and mods with my Sony devices, but that was mainly because I wanted stock android and some more features. The thing is that I have almost anything I need with this device, with some minor wishes. So I can leave without flashing custom roms and kernels, but I wanted to just root and at least install Adaway(!!!!!! I cannot leave with those ads!!!!!!), Titanium Backup and some other similar root apps that don't really do any harm. Have you tried rooting Android 10 and it was unusable? Do you suggest that it is not really worth it? The thing is that I love Android 10, the gestures and all the features, and I could not go back to Android 9, even though I only used the phone for a week, I am used to it and really like the way it currently is.
7)Hmm okay so I should not really mess with that. Maybe as I saw online, when flashing stock or unrooting, it is best to flash the same thing to both a and b slots, seems a bit complicated but whatever
Thank you for being so helpful!!

arismelachrinos said:
I really cannot thank you enough for your time. I truly appreciate it very much.
1) Very clear.
2) Do you happen to have a link or do you know how to check if my phone supports unlock_critical? How can I check if I have that newer bootloader? Or do you remember where did you learn this?
3) Thank you so much about that. Very clear aand you just saved my phone
4) Very clear.
5) Thank you for the info! Interesting, I was searching on how to root the device running Android 10 (I have fully updated and I really am not going back to Android 9 ), and I saw that you have to patch your boot.img with the Magisk app, and then flash it with fastboot. So first you get the factory image from google and you extract the boot.img and insert it to the phone. Then you load it into Magisk app and patch it. Then moving the patched to the PC, booting to bootloader and flash it on boot partition. This is the way I saw on how to get root working fine with Android 10, not sure if it is the best method or the worst.
6) What do you mean with "go up to August"? Do you mean that the "oldest" image I can flash is "9.0.0 (PQ3A.190801.002, Aug 2019)"? So one cannot go back to 8.0.0 and Google has done something to prevent us from doing that? Also, if I wanted to go back to that August image or any "compatible", the procedure is just to run the flash-all.bat file of that image?
I used to experement a lot with custom roms, custom kernels and mods with my Sony devices, but that was mainly because I wanted stock android and some more features. The thing is that I have almost anything I need with this device, with some minor wishes. So I can leave without flashing custom roms and kernels, but I wanted to just root and at least install Adaway(!!!!!! I cannot leave with those ads!!!!!!), Titanium Backup and some other similar root apps that don't really do any harm. Have you tried rooting Android 10 and it was unusable? Do you suggest that it is not really worth it? The thing is that I love Android 10, the gestures and all the features, and I could not go back to Android 9, even though I only used the phone for a week, I am used to it and really like the way it currently is.
7)Hmm okay so I should not really mess with that. Maybe as I saw online, when flashing stock or unrooting, it is best to flash the same thing to both a and b slots, seems a bit complicated but whatever
Thank you for being so helpful!!
Click to expand...
Click to collapse
It’s really my pleasure! And I’m just as thankful that you/anyone would even go through the trouble of reading all of that…!
1) Thank you for the compliment
2)Usually, if your bootloader version is within a certain version – which you can find when in bootloader mode – then you either do or do not need unlock_critical. I can’t remember how many months prior to Android 10/Q, it was within 6 I believe, so any bootloader version from 5 or 6 months ago to now, and obviously if you’re on 10/Q, you would not need to run the command unlock_critical. But, if anything, you don’t have to have any fear of it, whether you need to or not, or don’t know your bootloader version, running the “fastboot flashing unlock_critical” when you don’t need to will just amount to a simple error and nothing bad will happen. And if it does end up doing something, well, then that’s a good thing. It almost amounts to unlock_critical-ing twice, the second on will just state that it’s already unlocked and that’s it.
If anything, I believe I found the resource here from the great Az Biker: https://forum.xda-developers.com/showpost.php?p=78908055&postcount=2843
If you are very curious, it should address much of what you’re seeking and/or at least point you to where you might find that information.
3) You’re very welcome. It really is a good thing that saves you in the future, and saves those who try to help some grief as well.
4) Thank you for the compliment.
5) I would say that the process you described is certainly doable, but is far from the best/easiest. From my experience helping many here on this forum, many bugs or things go wrong when loading the stock boot.img to the phone, having Magisk modify it, then getting the modified boot.img and successfully flashing it. More often than not, one ends up having a device turn into a boot loop and are usually forced to flash the stock boot.img and have to give it a number of tries.
The best way (subjectively) is to download the Magisk installation .zip. Then boot into TWRP (which doesn’t mean you have to replace the stock recovery since you can temporarily boot into it), and “Install” it using the .zip. Then everything is automated and done for you, if anything goes wrong you have an output log you can use to troubleshoot, but it seems best to leave it to the experts who created all this than us manually attempting to ourselves.
Oh and AFAIK this method still works on Android 10/Q as it has for Pie and Oreo.
6) I meant that, if you did not wish to update to 10/Q, then you shouldn’t do anything newer than from August’s security update/patch, since all the Full Factory images and updates are of 10/Q. But, if you go to Google’s Developers site, you’ll see that they pretty much list and make available all the Full Factory images ever published; to the point that there are some that go back to Oreo!
And everything you’ve said is understandable. And I kinda feel the same way. For me, in my humble opinion, it is supremely good idea to root and for whatever issues you get doing that, the returns are incalculable. It is most definitely worth it/rooting! The extra options and customizations and modifications all make it worth while and more! And, even if rooting gives the capability of rendering the device rather unusable, take confidence in that Google, in all their “infinite wisdom”, gave us “Bootloader Mode”…and pretty much, as long as you can get into Bootloader Mode and successfully connect to a computer, your phone would never be considered too far lost/gone. I’ve only witnessed that be opposite on less than a handful of cases.
But, most importantly, and if you have been in the rooting and ROMing game, you should well know this, but the most vital part of having root access is the ability to make the best backups! So, as long as you make sure to backup (Nandroid is best) and key times, running into some pitfalls here and there shouldn’t take you all the way out of the game….
7) Yeah…I mean, it is rather fascinating, and when up against an issue and you have an idea that deals with it, that’s when you can read up and learn about it and experiment I imagine. But for me and one of the great ones here in all of XDA, we’ve done all the custom ROM, custom recovery, custom kernel, Full Factory recover, root, Magisk modules, theming, Xposed, and countless other things, and all without the need to ever mess with manually or forcing an assignment between the two.
Again, it’s my pleasure. And if you any further questions or thoughts, bring them on! I’d be happy to address them…
Hope these are helpful….

Thank you all very much! I am pretty busy these days so once I find some time I will do more research and root it.
@simplepinoi177
I am not sure if your paypal address works, I felt like buying you a coffee earlier, the least I could do with all the time you spent explaining

Oh forgot to ask some minor things,
to make a nandroid backup, I just send twrp.img via fastboot to the phone and boot into it and make it? And if I want to revert back I do the same and restore it?
Also if TWRP asks me the question about if I want to enable modification to the system, what do I answer? Either for the nandroid backup, the restore or for flashing magisk.zip? Do any of those require that enabled?
Lastly, I understood that just unlocking the bootloader alone can result in no OTAs. But, will I keep getting the security updates? I heared something about security updates that are frequently available from the playstore or something like that but I have the phone for less than a week and haven't gotten anything. No OTAs mean no security updates as well? Or they are irrelevant and I will keep getting those security updates once rooted?

arismelachrinos said:
Oh forgot to ask some minor things,
to make a nandroid backup, I just send twrp.img via fastboot to the phone and boot into it and make it? And if I want to revert back I do the same and restore it?
Also if TWRP asks me the question about if I want to enable modification to the system, what do I answer? Either for the nandroid backup, the restore or for flashing magisk.zip? Do any of those require that enabled?
Lastly, I understood that just unlocking the bootloader alone can result in no OTAs. But, will I keep getting the security updates? I heared something about security updates that are frequently available from the playstore or something like that but I have the phone for less than a week and haven't gotten anything. No OTAs mean no security updates as well? Or they are irrelevant and I will keep getting those security updates once rooted?
Click to expand...
Click to collapse
So, about booting TWRP...
You can temporarily boot into TWRP just the one time if you wish. If you are using the newest version of TWRP (for the Pixel 2), they actually give an option to flash and replace the recovery with TWRP from within their recovery environment; I'm guessing they use the temporarily booted twrp.img to install. In any case, you can find the option in the Install section. In any case, it's up to you whether you install it as your custom recovery, but it's easy enough to restore it back to stock recovery either by manually flashing the stock boot.img (and maybe dtbo.img for good measure, as I'm unsure...) and/or if you update your device via a Full Factory (or even a downloaded OTA) image, as that will update and replace the boot partition regardless...
So, about the alert for enabling modification to the system; In the past, I had always enabled it. Of course you would want to have r/w and mounting capabilities towards the device's system and data partitions. But keep this in mind...until the TWRP team updates the latest version, there is no write capabilities/permissions. It will pull up an error that it either can't mount or doesn't write -- For this reason, I'm holding off so I don't have firsthand experience... -- but installing and flashing and backing up from within TWRP does work even if it spits up some errors. What you should be careful about is if/when it asks to install it as a "system service" or something, as general consensus says at no circumstance should you do this as it "forks" up many other things while at it.
But, to answer your question directly, I'm unsure whether you can or cannot install Magisk root or restoring without enabling this "modification" capability, but I say it can't hurt.....
As for your inquiries on OTAs, as I understand it (so anyone please correct me if I'm wrong), but the monthly security updates come with the OTAs (also monthly, so I believe they may be one in the same). I'm unsure about the whole seeing the security updates on the Play Store or something like that, but I highly doubt that is the case. Conventional knowledge says that you can only get these either from the stock System Updater or if you download them yourself and either sideload or "flash-all" it. That's why many (most) experts will download the Full Factory image every month (usually first Monday of the month) and we have this whole step-by-step process in updating platform-tools, unregistering Magisk modules and screenlocks/fingerprints, running the flash-all, temporarily booting TWRP, installing all custom modifications (Magisk last), rebooting after each and every flash/install, then going back into the OS and resetting up the screenlock/fingerprints and Magisk modules. As it would be nice if we could simply and always use the stock System Updater, but in any case, one would need to re-install all the custom modifications anyways. So, it is one of the sacrifices/compromises having a rooted Pixel 2….
But it is peculiar that you haven’t gotten any alert (unless you inadvertently updated to the latest already), for it still should alert you that there is an update available, and usually, if you have unlocked your bootloader, while it’s downloading and attempting to install, it will throw up an error; but everything would look like normal up to that point. But, then again, Google notifying updates on their various devices are intermittent at best. It would be simpler and best if you just keep it in mind that there’s usually the monthly update on/after the first Monday of the month and do what we all do and have to manually install the updates to keep most up to date.
If there’s anything else, you know you can ask…
Good luck and hope this helps…!

I'm on 10 with an unlocked bootloader, 1st gen Pixel. I still get security updates. Twrp doesn't mount /system or /vendor, so I take system/vendor IMAGE backups with no issue. Not sure if I'll get updates still after unrooting. I've always flashed factory after rooting. Theoretically it should return to stock if you flash the Magisk uninstaller. The boot image (boot + recovery + base system) will be restored. You should then be able to get OTA updates. They will be installed to the OTHER slot, so if the phone fails to boot (3 times?) it will switch back to the first slot. If you have issues and want to go back, you can manually switch slots in fastboot or go into twrp, tap reboot, tap the other slot, then reboot system. It will show a message that the slot has changed. You can of course always check the active slot in fastboot to make sure. If you want to roll back an OTA update, reboot to twrp, change the active slot, then reboot system, and it should boot to the older version. Make sure to turn off automatic updates or else it will redownload the same update again. I believe I've lost twrp by installing an OTA update, which installs to the inactive slot, which overwrites recovery, and then boots to that slot. Meaning if you don't have a pc to switch slots in fastboot, you can't go back to the first slot which still has twrp. The command is fastboot set_active, something like that. Quick google search.. No pc means no restore if something goes wrong while you're away from a computer. The only way I know of to change slots at that point is to hard reset 3 times, which will trigger the phone to switch slots. ALWAYS reboot after flashing bootloader/radio. I'm decently sure that the bootloader has to match the system, so if you install lineage Pie, you need to flash the bootloader/radio from Pie or the phone won't boot. Flash bootloader, reboot, flash radio, reboot, flash matching rom. It is technically possible to have dual boot, where one slot is lineage and the other is stock, as long as they're the same Android versions. Lineage Pie/stock Pie for example, because the bootloader won't match if you flash Lineage Oreo/stock Pie. Keep in mind OTAs will overwrite twrp with stock recovery, so if you reboot, you might lose access to twrp, and I don't know of a way to OTA and reboot on the same slot. I don't know if there is an app or command for this, WHICH WOULD BE REALLY FREAKING NICE. Also, when restoring boot from twrp, I always reflash twrp to make sure. It will install to both slots. You can keep a copy of twrp on your data partition. To reflash twrp from within twrp, Install > Select Image > find twrp.img > flash to RAMDISK. If you flash to boot, it will overwrite system, and leave you with only twrp. When installing in older twrp's, I believe it will install to the same slot. With newer twrp's that specifically support Treble, it will flash to the other slot. Don't quote me on that. Due to the single data partition, there's a chance Lineage will have issues with stock data. I've never seen it though. I've dirty flashed a couple times with few issues. I think I've even dirty flashed different OS versions. If you get app crashes, open that app's info, delete its storage/cache, and reopen the app. Most of the app data is the same across versions anyway. The Pixel is a complete pain in the ass when coming from non Treble phones. Sorry if this is repeated info, the posts above are LONG lol. Hope this helps.
Edit- not sure if relevant to you, but I get bootloops when flashing twrp to the ramdisk. There should be an option in twrp to fix it. I always do this after flashing twrp this way.

Question How to keep rooted RedMagic 6/6s up to date?

Hello there.
After some struggles I got my phone rooted, found that fingerprint doesn't work, then went back and forth for quite a bit, putting my phone into and out of multiple boot loops and stuck red magic icons along the way. Suddenly 4.15 dropped...and it's not on redmagic.gg site...just as I decided i want to root my phone after all.
I have 3 questions. First, may I ask if there is a way to extract boot.img out of my phone?
Via adb shell I was able to locate both root_a and root_b. However since I don't have root access I can't actually get them out of my phone (i.e. dd if=... of=... gives a nice permission denied). There are also talks of using custom recovery to extract boot image, however I wasn't able to find any for redmagic 6. Am I missing anything?
Second, I noticed that fingerprint reader dies as soon as I unlock flashing, not when I flash unsigned images. However words in the shadow (basically that 1 guy in that how to guide on this forum) speaks of a way to maintain fingerprint functionality on a rooted phone. May I ask how that might be done? More whispers enveloped in darkness (also 1 guy in the chinese nubia forum) tells of a way to root while not even unlocking bootloader. May I ask what is that sorcery?
Finally, despite this being my first phone with good fingerprint scanner, I've grown to really like it. I noticed there's no data wipe on relocking bootloader. Is it possible to makes some changes (say Vance my youtube apps, modify some settings, get rid of some bloatware) before locking back?
Last I did this (I installed vanced my youtube, installed local update, then relocked bootloader) I was sent into a boot loop that took a bit to get out of. I'm a tad scared but also can't tell if it categorically won't work or I was perhaps just unlucky.

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Hello everyone. Today i will be guiding you all for rooting Red Magic 6/Pro with bootloader locked as well as FP working. Download the attached file. extract on pc. Now first things first enable developer options and Allow oem unlock. Now once...
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