[Superseded] Crossflash US Unlocked Pie to your Bootloader Unlocked V40

[Xsavi]

SUPERSEDED: Go Here​

Prerequisites:
V35 Engineering Bootloader flashed to your device (Stock bootloader will NOT work for this)
USB 2.0 (USB 3.x does not work well with ADB or Fastboot)
The V40 Pie Conversion Tool
Be in fastboot mode before attempting this
Patience
ADB and Fastboot DRIVERS. Platform tools are already included in the archive
Windows. The tool is not designed for Linux.
This will NOT sim unlock your phone[/CENTER]

Note: I'm not responsible for any bricks that come about from using this tool. Once you crossflash, there's NO going back unless you have backups of your partitions, or a KDZ specifically for your device. I'm going to say this again, DO NOT use USB 3.x while attempting this. You will run into errors. You won't see anything for a little bit when it gets to flashing system_a and vendor_a because it has to load those images into ram.

Download the tool: Google Drive

1. Download the archive and unzip the tool.
2. Navigate to the folder you unzipped the tool to.
3. Enter the folder and inside the folder you should find "V40PIECONVERSION.cmd". Ignore the one with the "Stock Boot" at the end. All it does is flash the stock boot image instead of the TWRP that is required to do this.
4. Execute the batch file and follow the instructions. When the batch file is done, Pie will be flashed, but it will not boot due to encryption. We're going to disable that.
5. Boot TWRP by performing a master reset. To perform a master reset: Press and hold Vol- and Power. When you see the "V40 ThinQ" logo release the power button and quickly press back down. Keep holding Vol- and Power until you see a factory reset screen. Finally, follow the prompts (yes) and you should be in TWRP.

TWRP Instructions​

Head over to the wipe menu and format data (to remove encryption).

Next, head over to mount and mount vendor. Mount ONLY vendor.

Now, open a command prompt, navigate to the folder where you extracted the tool, and open a command prompt inside the folder (Type "CMD" in File Explorer's Address Bar)

Execute the adb command:

adb pull /vendor/etc/fstab.judypn

Edit the file (fstab.judypn) in your favorite text editor and on the /data mountpoint change "forceencrypt" to "encryptable".

Save and Close the file and push the file back with the command:

adb push fstab.judypn /vendor/etc

Now that encryption is disabled, you NEED to flash back the ORIGINAL boot image that's included with the tool. In order to do that, we need to get back into fastboot.

To get back into fastboot, we need to: Make sure USB is still plugged into the phone. Press and hold VOL+ (Or vol up). Power off the phone (Via TWRP reboot menu) while still holding vol+. Keep holding VOL+ until you see download mode flash for a brief second and you should be in fastboot. The fastboot you see now isn't the V35 Engineering Bootloader. It's the stock pie bootloader. Wiping the laf_a partition allows access to fastboot on devices that are locked (Nearly all US Carriers).

Finally, run the commands:

fastboot flash boot_a boot_a.image

and

fastboot format userdata

You should run into an "encryption unsuccessful" screen. Just hit reset phone. You may have to reboot once or twice to get to the setup screen.

For those of you that want root, here's a patched Magisk boot image: Google Drive

You can flash it by running the command:

fastboot flash boot_a magisk_patched.img

Make sure you open a command prompt in the directory you downloaded the image in. If you don't have adb and fastboot in your environment path, just place it in the V40PIEConversion folder and flash it from there.

 

[Evilmonstertruck]

How do you get the v35 bootloader on stock Att ?

 

[Xsavi]

How do you get the v35 bootloader on stock Att ?

Contact @vbenkovskyy on Telegram. He is an awesome guy. Of course, it isn't free, but his prices are better.

 

[rjcarter3]

Confirmed working - thanks Xsavi for an excellent guide!

 

[avaie]

Would this method work on the T-Mobile variant? Is there a fee [anywhere]?

---------- Post added at 04:16 PM ---------- Previous post was at 04:12 PM ----------

Can someone comment on this?

 

[Ainz_Ooal_Gown]

Would this method work on the T-Mobile variant? Is there a fee [anywhere]?

---------- Post added at 04:16 PM ---------- Previous post was at 04:12 PM ----------

Can someone comment on this?

://youtu.be/nSeqIfQeWi4

No T-Mobile is not supported

 

[Xsavi]

Would this method work on the T-Mobile variant? Is there a fee [anywhere]?

---------- Post added at 04:16 PM ---------- Previous post was at 04:12 PM ----------

Can someone comment on this?

://youtu.be/nSeqIfQeWi4

Ainz is right. You'll end up with a brick if anything.

 

[T3R4BYTE]

Confirmed working on my att variant. ? Thanks again for the great guide ?

 

[Xsavi]

Confirmed working on my att variant. Thanks again for the great guide

You are very welcome! Feel free to contact me if you run into any issues.

On the plus side, your b-slot is untouched throughout all of this, so you can use that to re-root or flash backups should something go wrong, or update. Enjoy the pie.

 

[rmgibbs1861]

You are very welcome! Feel free to contact me if you run into any issues.

On the plus side, your b-slot is untouched throughout all of this, so you can use that to re-root or flash backups should something go wrong, or update. Enjoy the pie.

Will this work on the LG V40 International?

 

[Xsavi]

Will this work on the LG V40 International?

Yes it will.

 

[rmgibbs1861]

Will this work on the LG V40 International?

One more question, How will further updates be done after cross flashing? Thank you!

 

[Xsavi]

One more question, How will further updates be done after cross flashing? Thank you!

By flashing System, Vendor, and boot.

 

[twoxa]

Very confusing. Which variants of V40 this is going to work for?

 

[awireless]

How to get the v35 engineering bootloader on the phone the only method ive heard about is through octoplus jtag?

 

[Ainz_Ooal_Gown]

Very confusing. Which variants of V40 this is going to work for?

Well it worked for all US Carriers except for T-Mobile

 

[jass65]

had my sprint v40 bootloader unlocked from octoplus and tried this cause i hate sprint SW (activation screen).it flashed everything from batch file fine but when i went to boot into twrp it booted into normal recovery with the rainbow circle "erasing" then rebooted into os but it was all korean and the android version was 8.1. wtf lol? trying it again now, yes im using "V40PIECONVERSION" not the stock one.

 

[Ainz_Ooal_Gown]

had my sprint v40 bootloader unlocked from octoplus and tried this cause i hate sprint SW (activation screen).it flashed everything from batch file fine but when i went to boot into twrp it booted into normal recovery with the rainbow circle "erasing" then rebooted into os but it was all korean and the android version was 8.1. wtf lol? trying it again now, yes im using "V40PIECONVERSION" not the stock one.

Did you check to make sure you are on Slot A and not B? Becuase i remember when i had everything flashed the first time i tried to boot TWRP in Slot A and somehow ended up switching to Slot B

 

[jass65]

Did you check to make sure you are on Slot A and not B? Becuase i remember when i had everything flashed the first time i tried to boot TWRP in Slot A and somehow ended up switching to Slot B

thats what it ended up being. xSavi helped me out :good:

 

[asdfeproiu]

Hi guys,
I have a Sprint V40 bought off of Taobao that was rooted, sim unlocked, and crossflashed to US Cellular 11d but after I installed Pix3lify trying to get gestures on 8.1 I lost root. I don't seem to be able to get into fastboot, either with Vol- + cable or via adb, but I have an unlocked bootloader and I can get to download mode. Factory reset just reboots. Any tips as to how can I get root back, or upgrade to Pie? Can anybody please explain how to switch from slot a to slot b and vice versa?
Jeff