[LG G8 Guides, News, & Discussion] antintin:
Edit before publishing: I started writing this for all variants other than sprint, but I'll now make a separate thread for variants that have kdzs and those that don't, otherwise this will be a mess.

Firstly, keep in mind that no one is responsible if you end up bricking your device! There is currently no way to recover from a hard brick other than sending your phone in for repair, so make sure you follow every single step carefully if you wish to proceed!

Additionally, flashing an xbl through DD may not pass randomly even if it appears that it has worked, so be aware of the risks. Only at&t users will need to flash the xbls anyway since that is the only variant other than sprint which does not have kdzs available.

Users with the AT&T variant who are stuck on pie: temp root only works on android 10, as such you will unfortunately not be able to bootloader unlock your device. The firehose may leak at some point in a few months, and you will be able to unlock (and update manually) if it does.

The process for unlocking bootloaders on models other than the sprint one (specifically At&t for this guide) is practically identical; however, it uses different xbl_config.img and xbl.img files, which need to be specific for your device from the pie firmware.

The version naming may not be the exact same for other models, but you just have to ensure that you are on the March patch or below. If you are on April, you can find the guide to switch slots and do so in order to revert to March. To STOP UPDATES, fully uninstall or disable the update center packages either with ADB or package disabler pro for LG, which you can easily find online.

So I repeat, you're going to follow the sprint g8 bootloader unlocking guide, but you have to use the xbl and xbl_config for your device rather than the ones provided in the sprint guide. The engineering abl is the same, but I'll include it here anyway so that you don't have to mess around with any of the files provided in the sprint g8 guide.

Now, steps that are to be ignored and steps that may differ slightly:

Keep in mind that I'm only mentioning what you should be aware of and what may be different, but you still have to follow the guide written by BrandonB1218 in general.

1a: Of course, you still need a vulnerable firmware, and sadly AT&T does not provide kdzs, so you cannot bootloader unlock if you are on the May patch.

You can Ignore this: I found that another method that most likely stops updates is following this guide on youtube. It's supposed to bypass frp lock, but it also gets by all the LG agreements you have to accept, so it will ask you to agree to these if you ever open up the software update option in settings and will probably not update if you don't.

2: Some people had issues with different versions of the mroot script, so try all of them before you come asking for help please. I also suggest that you just temp root without running the temp root magisk setup as you may end up bricking if you accidentally flash a module or make magisk flash a patched boot img (DO NOT FLASH ANYTHING OTHER THAN WHAT'S INCLUDED IN THE GUIDE).

I suggest running the backup script and the commands to make sure you're completely safe, but make sure you keep them separate because a lot of the partitions included in the commands that [MENTION=2768375]BrandonB1218[/MENTION] mentioned are device specific and include your IMEI. The backup script should only backup the partitions that aren't device specific such as system, and this is probably the one you'll need if at all because you shouldn't be touching other partitions. STILL DO BOTH THOUGH

3a: Yes, you have to run the command to find out which slot you're on, but you will not flash anything from the pie or 20d sprint backup that's listed there, or else you will likely brick.

3b and 3c: This should all be the same: If your active slot is A, follow 3b, and if your active slot is B, follow 3c. The commands should also be the same, just with different files.

If your active slot is A, but the files included for your device are also named xbl_a.img, for example, you can just rename them to fit with the command.

Otherwise, you can just change this, for example,

dd if=/storage/emulated/0/Download/xbl_b.img of=/dev/block/bootdevice/by-name/xbl_b

to this:

dd if=/storage/emulated/0/Download/xbl_a.img of=/dev/block/bootdevice/by-name/xbl_b

You also need to flash the engineering laf, so either rename the file or change the command so it works. The link is embedded

Overall, its just important that you take the right file in the first part of the command and flash it to the correct partition of the correct slot in the second part.

If I remember correctly, the method to boot into fastboot is hold vol- and power until the screen goes black (while the phone is plugged into the computer) and then to let go of power as soon as that happens.

4a and 4b: You do not want to do either of these as the boot img and other partitions vary per variant. I unfortunately do not have the magisk patched At&t boot img, but you can patch it yourself from the backup you made and flash it. It might be good to do this beforehand, but you could also just temp root again and dd flash it.

Alternatively, you can flash the metaphysics 1.7 kernel with twrp and magisk included, but you still have to follow the rest of the twrp installation in the sprint g8 bl unlocking guide. TWRP is the same for all US variants.

Congrats! You should now be bootloader unlocked and ready to go at this point. If you ever find yourself unable to boot on the slot which DOES NOT have the engineering abl, you can always switch to the slot with the engineering abl, go to fastboot, and fastboot flash your backed up partitions.

Credits:

Obviously to BrandonB1218, for writing the sprint g8 bootloader unlocking guide

vl48 for basically answering all my questions and providing the needed files

j4nn for writing the temp root

Mr. Zhu for twrp

KamioRinn for metaphysics

Anyone else who contributed in telegram to get this to work!