LG V20 H918 unlockable bootloader, but can't actually flash recovery
So I just picked up the T-Mobile V20 and unlocked the bootloader. Unfortunately, I soon found that it doesn't really get me anything because we can't actually flash custom recoveries (at least not without privilege escalation exploits like dirtyCOW that were used on older firmware versions).

Can someone from LG give some input on this? The purpose of unlocking the bootloader is to allow for custom ROMs and rooting, yet both of those require installing a custom recovery first. Why are we blocked from doing this?
Posted on 25-Aug-2017

Re:LG V20 H918 unlockable bootloader, but can't actually flash recovery


Where did you unlock the H918?

In accordance with LG's policy, we provide a way to unlock for the supported devices only, and H918 is not in that list.

And we don't provide any other information about rooting LG devices.

We are sorry that we can't be of much help.

Thank you.

Posted on 29-Aug-2017

Re:LG V20 H918 unlockable bootloader, but can't actually flash recovery

I unlocked the phone myself by enabling OEM unlock in developer options and using fastboot oem unlock. It did not need a LG unlock code and my bootloader is now unlocked.

The issue I'm having is with the fastboot implementation. Normally fastboot flash recovery is used to put a custom recovery on the device to enable further modification, but the flash command has been disabled. When I run fastboot flash recovery, I get the following error:

sudo fastboot flash recovery twrp-3.0.2-1-h918.img 
target reported max download size of 536870912 bytes
sending 'recovery' (24092 KB)...
OKAY [ 0.698s]
writing 'recovery'...
FAILED (remote: unknown command)
finished. total time: 0.717s

This effectively renders the unlocked bootloader worthless since I can't actually put any custom software on the device to take advantage of this.

I'm looking for an official response from LG on this why they would allow the device to have an unlockable bootloader, but then not have a proper fastboot implementation for it. Is there another channel I should use to contact LG about this besides the developer forum?

Posted on 30-Aug-2017