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Ronith128

Member
Dec 24, 2018
43
78
This Guide will explain how to root your LG G8X

* Disclaimer*
* I am not responsible for bricked devices, dead SD cards, thermonuclear war,
* or you getting fired because the alarm app failed. Please do some research
* YOU are choosing to make these modifications, and if
* you blame me in any way for what happens to your device, I will laugh at you.
*Wait, what? No. Me or somebody else will help you
Prerequisites
Unlock phone using the guide here: https://forum.xda-developers.com/t/guide-how-to-unlock-bootloader-of-lg-g8x.4198025/
Do not restore abl before rooting.
Magisk Patched Boot (20e, Indian Variant): https://drive.google.com/file/d/1s2A7RUOptXer5LGMtbGV9SKg0kcyL_NP/view?usp=drivesdk

1. Download the magisk patched boot.

2. Copy it over to your fastboot directory.

3. Connect phone in fastboot mode.

How to put phone to fastboot mode?

#1: Using Button Combination

Power off phone, press and hold Vol- and insert usb cable. You’ll be in fastboot

#2: Using ADB

Connect phone to pc, enable USB Debugging. Then run this command
Code:
adb reboot fastboot

4. Now run the command
Code:
fastboot flash boot Magisk_Patched.img
fastboot reboot

5. Download and install Magisk Manager

6. Done! Your phone is rooted now.

To restore Network follow the guide in bootloader unlock thread...

If you have a different G8X variant or are on a different firmware

1.Backup boot_a or boot_b using QFIL (Partition Manager>Read Data, Check Bootloader unlock guide for more details)

2. Install Magisk Manager

3. Click on Install and use Patch image function.

4. Save the boot image to pc.

5. Flash it in Fastboot using the command given above.

Known Issues: FP is broken

Thankyou :)
 
Last edited:

Starfox

Senior Member
Jun 1, 2007
279
105
(copypasta'ed from the other thread)

For those who have yet to do this, I suggest extracting boot_a/b at the same time you flash the abl image. Prior to doing the fastboot oem unlock, use the Magisk patch file option (installed on the same or another device, and doesn't need to be rooted) to create a rooted boot image using adb push/pull. Once you fastboot oem unlock, go back into the bootloader and instead of fastboot flash boot, you can fastboot boot magisk_patched.img.

Once you go through the setup, you can open Magisk, which will download and install the full Manager app, at which point it will most likely reboot. You will need to fastboot boot again, and you should be able to do a normal Magisk install. I've usually found that as long as the patched boot is of the same Android version and within a few month of the patch level, it'll boot happily enough to do this. Afterwards, you can restore your abl image as you no longer need to use fastboot commands.

Doing this allows Magisk to save the stock boot image, and also allows you to get OTA updates by restoring the stock image right before any updates. Otherwise you will never be able to do an OTA update as it checks if the boot partition has been modified before installing the updates. Since there are no kdz for the US carrier models, your only other option would be to "brick" your device to try get your carrier's service center to restore a working firmware image.

-- Starfox
 
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yorkz

Member
Oct 10, 2017
6
0
Sorry I posted in the wrong thread. I've deleted the contents, but wasn't able to delete the post itself
 
Last edited:

LimaBEERRE

Member
Aug 17, 2013
31
3
Brasília
Guys, I am trying to follow this guide using the "different variant" method, but as soon as I boot after flashing boot.img the touchscreen doesn't work. Only way to get it back is to flash the boot_a.bin and boot_b.bin using QFIL. What am I doing wrong?
 

Adminislayer

New member
Jan 30, 2021
4
1
Is there an update for magisk patch image for 20b (unlocked US variant)?

Edit: Got my 20b version rooted.
Downloaded stock rom for the G850QM20b, extracted the kdz file to dz to .img grabbed the stock boot_a.img file and ran it in Magisk manager app, took the converted .boot.a.img (now renamed magisk_patched_clT14.img) and dropped it in platform tools, went fast boot, then flashed it. Came back up great, no issues and root access is clear.
 
Last edited:

robnitro

Senior Member
Feb 21, 2010
80
13
Samsung Galaxy S21
I cannot.I've tried everything I know to do.I'm so cautious with this phone because I got it at a steal off of eBay and would hate to brick it.
follow the video here, I got it to work
hold power and vol down , itll countdown to reboot.... as soon as it does that- while holding down and power tap the up button
 

sino70

Member
Feb 15, 2021
6
1
LG G7 ThinQ
Is there a image for the g850UM20g?
edit:
I have a copy of boot_a but in the fastboot it tells me that I am using abl_b and I don't know if boot_a is compatible with abl_b and i can't enter EDL mode
 
Last edited:

zdanee

Senior Member
Sep 27, 2012
88
16
So my understanding is you can have a rooted phone, but FP will be broken no matter what and possibly audio as well. You can fix this by reinstalling a Pie version from KDZ, fix it then reinstalling a 10, but then the root will be gone (but the bootloader remains unlocked). Is this correct?
 
So my understanding is you can have a rooted phone, but FP will be broken no matter what and possibly audio as well. You can fix this by reinstalling a Pie version from KDZ, fix it then reinstalling a 10, but then the root will be gone (but the bootloader remains unlocked). Is this correct?
Yes, rooting will be gone and Bootloader remains unlocked forever. You have to root it again in A10
 
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zdanee

Senior Member
Sep 27, 2012
88
16
For anyone in the future: you can have both root and fingerprint. Follow the bootloader unlock guide up to the point where you have to backup your boot_a. After that you don't use the patched boot_a in the instructions, instead patch your own version with magisk and flash that instead with QFIL. I now have a working V20h EU version with root, fingerprint and working audio.
 

zdanee

Senior Member
Sep 27, 2012
88
16
Anu one have LMG850UM 20f magisk patched boot file?
Country china
Lg g8x
I do. But it's an EU version, so I'm not sure it would work for you. However it's easy to just make your own!
- Install Magisk manager on the phone. You don't need open bootloader or anything for that
- Get your own 20f boot_a using QFIL
- Copy your own boot_a to the phone or on an SD card
- In Magisk Manager you choose to install magisk, select patching an IMG file method and give it the boot_a
- If Magisk reports success you'll now have a magisk_patched_boot_a file. Copy that back to your PC
- Using QFIL flash that in place of your original boot_a
- Keep a copy of your original boot_a thou, you can go back with QFIL at any time.
- If you mess up royally and the phone doesn't boot, you can still recover it by re-flashing your firmware with LGUP 1.17. You'll have to download your region's firmware for that and you'll loose all data, so make a backup beforehand!
 

Attachments

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james508959

New member
May 28, 2021
4
0
For anyone in the future: you can have both root and fingerprint. Follow the bootloader unlock guide up to the point where you have to backup your boot_a. After that you don't use the patched boot_a in the instructions, instead patch your own version with magisk and flash that instead with QFIL. I now have a working V20h EU version with root, fingerprint and working audio.
Hi, thanks for sharing the steps!

I followed your steps but don't have audio/network/fingerprint after flashing patched boot. Later I also tried to restore abl_a/b, then I had audio and network working, but still no fingerprint.

In my case, fingerprint stopped working once bootloader is unlocked, before even flashing the patched boot.

Did you have working fingerprint right after you flash patched boot? Did you restored abl_a/b?

I also tried to follow another post to get fingerprint working, but I can only find 10b kdz of my variant (twn), I downgraded to android 9 using that kdz, still cannot get fingerprint to work.
 

zdanee

Senior Member
Sep 27, 2012
88
16
Hi, thanks for sharing the steps!

I followed your steps but don't have audio/network/fingerprint after flashing patched boot. Later I also tried to restore abl_a/b, then I had audio and network working, but still no fingerprint.

In my case, fingerprint stopped working once bootloader is unlocked, before even flashing the patched boot.

Did you have working fingerprint right after you flash patched boot? Did you restored abl_a/b?

I also tried to follow another post to get fingerprint working, but I can only find 10b kdz of my variant (twn), I downgraded to android 9 using that kdz, still cannot get fingerprint to work.
I also messed up at first, since there were no ready-made boot_a for my region/version I just grabbed the indian one for 20e, and yes, that did break my audio, fingerprint and possibly network, I didn't test that one. I did have a KDZ for my region thou, so I flashed back a 10c version, I needed the 1.17 tool, not the 1.14 or 1.16 one (those did not work) and in my case I needed the second version of 10c, not the first one to fix the fingerprint. After flashing 10c I did all the steps and regained my fingerprint reader without an issue (so no, it did not work right away, I did need to go into the service menu and do the test), audio and network also worked right away. After that I flashed my latest KDZ (20h) and using magisk manager made my own boot_a and was able to root with a working fingerprint. I did not dare to update Magisk after this thou, I only needed it to grant root for my adblocker, and it's hidden from everything else, I don't think I'll ever even start magisk again, so I don't really want to update it either.
 

james508959

New member
May 28, 2021
4
0
Did you restore abl_a/b at all? I can only get into download mode (to use LGUP) after I restore abl_a/b.

Anyways, I think flashing using LGUP overrided the abl, and that's why audio and network worked right away (to my understanding)

My LGUP tool worked fine, but there only 10b for my TWN variant, I couldn't find 10c anywhere... (only 10b, 20a, 20b available)

I never flashed other's patched boot, I used QFIL to get my boot_a.bin and patched it using Magisk on another phone. Then I used fastboot to flash boot. (I did this right after unlocked BL, all before I restored abl).

Did you also use QFIL to get boot_a or did you use KDZ extractor? I'm having problem with my KDZ extractor tool, encoding issue or sth.

My variant is G850EMW, should I try the indian 10c kdz (which is also G850EMW)? Would that work? Not sure what risk cross region flashing poses, or even if LGUP would let me flash it at all.
 

zdanee

Senior Member
Sep 27, 2012
88
16
Did you restore abl_a/b at all? I can only get into download mode (to use LGUP) after I restore abl_a/b.

Anyways, I think flashing using LGUP overrided the abl, and that's why audio and network worked right away (to my understanding)

My LGUP tool worked fine, but there only 10b for my TWN variant, I couldn't find 10c anywhere... (only 10b, 20a, 20b available)

I never flashed other's patched boot, I used QFIL to get my boot_a.bin and patched it using Magisk on another phone. Then I used fastboot to flash boot. (I did this right after unlocked BL, all before I restored abl).

Did you also use QFIL to get boot_a or did you use KDZ extractor? I'm having problem with my KDZ extractor tool, encoding issue or sth.

My variant is G850EMW, should I try the indian 10c kdz (which is also G850EMW)? Would that work? Not sure what risk cross region flashing poses, or even if LGUP would let me flash it at all.
No, I did not restore abl_a/b, and after KDZ the bootloder remained open, so there is no need to, the phone still reports an open bootloader at boot. If it _does_ override it thou it seems it's not neccessary to have, as I could root the phone and could keep the open bootloader anyways.

I used QFIL to get my own boot_a, and used it again to flash it back too.

My EU (Hungarian T-mobile) version is also G850EMW. My understanding is that if LGUP lets you flash a KDZ it's probably gonna work, but in the worst case scenario as long as you have a known good KDZ for your model you can always come back to that, so I guess you can experiment?

I've also only found a 20b version of KDZ for TWN, but it's release date is similar to 20h in the EU, so maybe these numbers doesn't mean they are the same KDZ, only that 20x meant it's Android 10 and the letter is the revision. Based on this it's possibe you don't need a 10c to restore your fingerprint, just try the earliest 10x KDZ you can get your hands on (for me the 10c was the earliest one). Alternatively you can try the 10c I used for mine, it's EU Hungarian, but the default language is still English and you'll re-flash it anyways: https://lg-firmwares.com/downloads-file/21667/G850EMW10c_00_OPEN_EU_DS_OP_1122
 
Last edited:

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  • 6
    This Guide will explain how to root your LG G8X

    * Disclaimer*
    * I am not responsible for bricked devices, dead SD cards, thermonuclear war,
    * or you getting fired because the alarm app failed. Please do some research
    * YOU are choosing to make these modifications, and if
    * you blame me in any way for what happens to your device, I will laugh at you.
    *Wait, what? No. Me or somebody else will help you
    Prerequisites
    Unlock phone using the guide here: https://forum.xda-developers.com/t/guide-how-to-unlock-bootloader-of-lg-g8x.4198025/
    Do not restore abl before rooting.
    Magisk Patched Boot (20e, Indian Variant): https://drive.google.com/file/d/1s2A7RUOptXer5LGMtbGV9SKg0kcyL_NP/view?usp=drivesdk

    1. Download the magisk patched boot.

    2. Copy it over to your fastboot directory.

    3. Connect phone in fastboot mode.

    How to put phone to fastboot mode?

    #1: Using Button Combination

    Power off phone, press and hold Vol- and insert usb cable. You’ll be in fastboot

    #2: Using ADB

    Connect phone to pc, enable USB Debugging. Then run this command
    Code:
    adb reboot fastboot

    4. Now run the command
    Code:
    fastboot flash boot Magisk_Patched.img
    fastboot reboot

    5. Download and install Magisk Manager

    6. Done! Your phone is rooted now.

    To restore Network follow the guide in bootloader unlock thread...

    If you have a different G8X variant or are on a different firmware

    1.Backup boot_a or boot_b using QFIL (Partition Manager>Read Data, Check Bootloader unlock guide for more details)

    2. Install Magisk Manager

    3. Click on Install and use Patch image function.

    4. Save the boot image to pc.

    5. Flash it in Fastboot using the command given above.

    Known Issues: FP is broken

    Thankyou :)
    1
    (copypasta'ed from the other thread)

    For those who have yet to do this, I suggest extracting boot_a/b at the same time you flash the abl image. Prior to doing the fastboot oem unlock, use the Magisk patch file option (installed on the same or another device, and doesn't need to be rooted) to create a rooted boot image using adb push/pull. Once you fastboot oem unlock, go back into the bootloader and instead of fastboot flash boot, you can fastboot boot magisk_patched.img.

    Once you go through the setup, you can open Magisk, which will download and install the full Manager app, at which point it will most likely reboot. You will need to fastboot boot again, and you should be able to do a normal Magisk install. I've usually found that as long as the patched boot is of the same Android version and within a few month of the patch level, it'll boot happily enough to do this. Afterwards, you can restore your abl image as you no longer need to use fastboot commands.

    Doing this allows Magisk to save the stock boot image, and also allows you to get OTA updates by restoring the stock image right before any updates. Otherwise you will never be able to do an OTA update as it checks if the boot partition has been modified before installing the updates. Since there are no kdz for the US carrier models, your only other option would be to "brick" your device to try get your carrier's service center to restore a working firmware image.

    -- Starfox
    1
    Is there a magisk patched image for the g850u20i
    1
    I have 20j and I can't even get into edl or fastboot... Can you get into fastboot mode? I've tried adb and button combos
    I cannot.I've tried everything I know to do.I'm so cautious with this phone because I got it at a steal off of eBay and would hate to brick it.
    1
    So my understanding is you can have a rooted phone, but FP will be broken no matter what and possibly audio as well. You can fix this by reinstalling a Pie version from KDZ, fix it then reinstalling a 10, but then the root will be gone (but the bootloader remains unlocked). Is this correct?
    Yes, rooting will be gone and Bootloader remains unlocked forever. You have to root it again in A10