First of all, This is not my original work. I am just sharing this GUIDE for easy Bootloader Unlocking and flashing Custom Recovery to L90.
Root Access required to Unlocking Bootloader and Flashing Recovery. If you are already rooted then go on, if not then down towelroot apk from https://towelroot.com/ and root your phone and install superuser from play store.
DEVICES FLASHED WITH THIS GUIDE AND TESTED OK: LG L90 (D410)
Follow this guide step by step :-
1. Download and extract L90_D4##_v10x_aboot.zip (# = your device model, x = version of stock firmware) and any custom recovery zip you want to flash from the attachments below this post to external sd card (aboot.bin should be on external sd (/storage/external_SD/aboot.bin) , not in any other folder.
2. Download and install terminal from play store and run it.
3. Now type following commands in terminal :-
(Grant superuse permission to terminal after typing "SU" command)
4. Exit terminal, download and install Flashify from play store. Run it and grant root access.
5. Tap on Recovery image > chose a file > select recovery.img file
6. Tap on Yup!
That's it you are done
HOW TO BOOT INTO RECOVERY PRESSING VOLUME AND POWER KEY
You can reboot to recovery via flashify app or following key combination: -
Power of your phone press both Volume Down + Power Button same time, As soon as the LG logo appears release both buttons and immediately press and hold same buttons (Volume Down+Power) again. Now Factory data reset screen will appear saying "Erase all user data & restore default settings?". Use volume down key to select "Yes" and press power button to confirm and now you should be in recovery. (Caution: Don't try this while stock recovery installed or it will erase all your data)
In case of brick or want to flash stock firmware, please follow this guide :
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