[LG V30 ROMs, Kernels, Recoveries, & Other Developm] ChazzMatt:
INSTALL or REINSTALL TWRP on PIE stock KDZ with ALREADY-UNLOCKED BOOTLOADER

THIS POST ASSUMES YOU HAVE PREVIOUSLY UNLOCKED BOOTLOADER, AND THAT YOU HAVE NOW UPGRADED TO STOCK PIE KDZ. YOU HAVE UNLOCKED BOOTLOADER and are STILL on firmware which has FASTBOOT FLASH COMMANDS.

If you have NOT yet unlocked bootloader on early Oreo firmware, then go read

post #2 of this thread

https://xdaforums.com/showpost.php?p=79964731&postcount=2https://xdaforums.com/showpost.php?p=79964731&postcount=2.

If you know how to install TWRP with fastboot commands, then just skip down to #7 - MORE TWRP ACTIONS for the Pie differences.

Stable TWRP 3.3.1 is recommended

by our TWRP dev for Pie.

________

6: INSTALLING TWRP AND ROOTING

Installing TWRP:

1. Switch back to developer mode, USB debugging. (OEM Unlock is now not selectable right now, greyed out. In a few days it will again be selectable.)

2. Switch USB to Photo again; default is charging.

3. As before, on your PC from the Android tools directory,

adb reboot bootloader

4. Fastboot flash recovery TWRP.img (Remember you re-named this file to just TWRP.img earlier.)

(This screenshot by @Wotta shows a LONG TWRP name. Ignore that. We re-named it TWRP.img. Still it shows you the environment.)

Do NOT reboot your phone after flashing TWRP! Instead, immediately boot to TWRP by using this command: fastboot boot TWRP.img

Ignore the bootloader unlock warning, which is your new splash screen. Eventually you will boot into TWRP.

6. INITIAL TWRP ACTIONS!

a. At the bottom of the screen, immediately swipe to allow modifications. Do NOT leave read-only, TWRP NEEDS to be able to make changes to your system.

b. Back up the system. This isn’t essential, but you’d be silly not to. (Has saved more than one person.) Select “back up”.

c. Select the microSD card for backup (or USB OTG).

d. Back it up. This will take about 10 minutes if written to micro SD card.

e. Do NOT install the TWRP "app" if offered.

7. MORE TWRP ACTIONS - Now turn off data encryption and install essential items… all in TWRP:

(This is not a "menu" in TWRP, it's merely a list of what you NEED to do before booting to the OS)

a. Wipe Data – Factory Reset

b. Install – set storage to the External SD (if you have a microSD card) OR drag necessary files over from PC once in TWRP.

c. Install the Magisk zip. (This is to give the encryption disabler root privileges)

d. Install @Zackptg5 Disable_Dm-Verity_ForceEncrypt_08.18.2019 (encryption disabler).

e. Install @JohnFawkes AnyKernel 3 RCTD Remover (root checker disabler); this disables LG's firmware root checks, which may impede performance.

f. FORMAT DATA (Select WIPE, then FORMAT DATA, then select yes.)

Do NOT delete your OS, but you do need to FORMAT your data , not just "wipe" it this time. Otherwise you may get an encryption error when you boot up the first time. If you get any red mount errors, go back to the TWRP reboot menu and select reboot to recovery and try to FORMAT DATA again. Then, after successfully formatting...

g. Reboot – "Reboot Recovery" from TWRP reboot menu (choose to reboot back to Recovery). Now that the data partition has been formatted, TWRP needs to reload the recovery partition for usage. If you skip this step, when Magisk is installed again below, it may think that /data is still encrypted and set "preserve force encryption". This is also a good sanity check that LG encryption has been removed from /data.

h. Re-flash the Magisk zip again. (This is to make sure, due to Pie changes.)

i. Reboot – to System (NOW you are finally rebooting your phone! Until now this whole section has been done within TWRP.)

(Thanks to @jdgesmlls for helping to re-write that previous section to clarify better. Also thanks to @downwiththebanksters for giving the entire post a thorough inspection to clarify/explain various points better.)

If booting fails with an encryption error, did you format (f above) the partition? If not, reinstall TWRP and go through the steps again.

You will now have a factory reset phone, and have to set up the phone again, but should have root (via Magisk.)

STRONG SUGGESTION: After successfully doing all this, when you finally boot back to LG Pie, install an app like this to easily facilitate rebooting to TWRP recovery in the future:

Recovery Reboot

. Allow it root privileges when asked by Magisk and put icon shortcut on your desktop.

Also, please make another TWRP backup. ;)

TLDR:

* flash twrp: fastboot flash TWRP.img (TWRP-3.3.1 re-named as just "TWRP.img")

* boot twrp: fastboot boot TWRP.img (TWRP-3.3.1 re-named as just "TWRP.img")

* swipe to allow modifications (do NOT leave read-only, TWRP NEEDS to be able to make changes to your system.)

* select WIPE data

* wipe caches

* flash Magisk.

* flash encryption disabler

* flash root check disabler

* FORMAT DATA, type yes

* reboot to TWRP

* re-flash Magisk.

* reboot to system

______________

STRONG SUGGESTION: After successfully doing all this, when you finally boot back to LG Pie, install an app like this to easily facilitate rebooting to TWRP recovery in the future:

Recovery Reboot

. Allow it root privileges when asked by Magisk and put icon shortcut on your desktop.

Also, please make another TWRP backup. ;)