[LG V40 ROMs, Kernels, Recoveries, & Other Developm] SGCMarkus:
#include "std_disclaimer.h"
/*
* Your warranty is now void.
*
* 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 if you have any concerns about features included in this Recovery
* before flashing it! YOU are choosing to make these modifications, and if
* you point the finger at me for messing up your device, I will laugh at you.
*/

Requirements

Unlocked bootloader

working ADB/fastboot on a PC

the TWRP image downloaded

Pie firmware on the active slot

Installation guide (pre metadata encryption):

Copy the twrp image to your phones storage and/or micro sdcard

Start cmd/powershell/terminal with working adb/fastboot

Reboot to bootloader

adb reboot bootloader OR

turn off the phone (or reboot), as soon as it turns on, hold volume down while USB cable is connected

If youre unofficially bootloader unlocked, and you nuked laf, its volume up and USB for you

fastboot boot TWRP-judypn-boot.img

Confirm allow system modifications if asked

Press cancel if asked for a password (aka when youre encrypted, could also be that it doesnt show you /data at all and no password screen)

Go to Advanced -> Install Recovery Ramdisk

Select the TWRP image which you copied to your phone/sdcard earlier

TWRP will now be installed to both slots (boot_a and boot_b)

Go to Reboot -> Recovery to make sure TWRP is successfully installed

Features:

Install recovery ramdisk:

Selecting this, and then an image (e.g. of TWRP) allows you to install the ramdisk (where TWRP resides for example) into both currently installed kernels/boot images

Inject TWRP after install:

Automatically injects current installed TWRP into the boot image of the ROM/zip youre installing when ticked

Broken:

LGs encryption on Stock

encryption on other ROMs(?)

How to flash ROMs (PRE metadata encryption):

Reboot to TWRP

Make a backup

Install -> select the ROM zip -> tick Inject TWRP -> Swipe for install

wait... ROM will be installed into the NON ACTIVE slot (if youre on a, it will be installed to b, and vice versa)

Reboot system

for gapps, magisk or other mods:

DO NOT REBOOT TO SYSTEM from last step

Go back -> Reboot -> select the non active slot (to where the rom got installed to) -> select recovery

Install gapps, magisk, and whatever else you want

Reboot system

How to initially flash ROMs (metadata encryption):

Reboot to existing TWRP

Make a backup of everything you want to keep

Copy backup to PC (or another external medium)

Flash the ROM

Do NOT inject TWRP (this will break recovery otherwise)

Go to reboot -> Select opposite slot

Reboot to recovery

Perform factory reset (this is to setup encryption)

Apply update (from ADB) with adb sideload for gapps/magisk

reboot to bootloader

fastboot boot judypn_TWRP_bootable-metadata.img

Use as usual

Reboot system

How to update ROMs (metadata encryption):

Reboot to bootloader

fastboot boot judypn_TWRP_bootable-metadata.img

Install -> Select ROM zip

do NOT inject TWRP

Reboot -> select opposite slot (it will tell you even which it installed the ROM to)

Reboot bootloader

fastboot boot judypn_TWRP_bootable-metadata.img

Install gapps/magisk

Or

reboot recovery

apply update -> from adb (in e.g. Lineage recovery)

On PC: adb sideload <new version zip>

(Advanced -> ) Reboot recovery

adb sideload gapps/magisk

reboot system

Warnings:

Updating a ROM means reflashing the mods you flashed too (e.g. Gapps), addon.d doesnt work properly

Be aware of the slot you are currently on

If youre flashing a ROM to a slot, make sure you also have the required firmware (abl, modem, and so on) in that slot

Infos:

System image/Vendor image and system/vendor are redundant, the image variants are direct copies of the partition (and also their size) while the others are "simply" files copied and repacked

How to use decrypted stock by [MENTION=5796697]Xsavi[/MENTION] : https://xdaforums.com/lg-v40/how-to/guide-twrp-data-access-stock-t3970149

Metadata encryption TWRP requires 10 firmware to use properly, no guarantee for it to work on Pie firmware!

Download:

Metadata bootable: https://drive.google.com/file/d/1hdzeH3AIQVf3siQNsI27IS_vmghPESEG/view?usp=sharing + Install zip: https://drive.google.com/file/d/1CQUfg54zD838detcIJqdRiKXdVNtd6Iy/view?usp=sharing

Bootable: https://drive.google.com/open?id=1UnIFbJlXHl6x4azq6H6yS-PRfk-omdTP

Old: https://drive.google.com/open?id=1p3IrbeOxM4ay01JccyifWDuxqqrE0_Dl

Sources:

device tree: https://github.com/SGCMarkus/android_device_lge_judypn-twrp/tree/android-9.0

kernel: https://github.com/SGCMarkus/android_kernel_lge_sdm845/tree/lge-pie-v409-20a

XDA:DevDB Information

TWRP for Judypn, ROM for the LG V40

Contributors

SGCMarkus

ROM OS Version: 9.x Pie

Version Information

Status: Alpha

Created 2019-09-20

Last Updated 2019-09-20