[Howto] unlock bootloader and get TWRP on ZUK Z2 Pro

[weimerd]

DISCLAIMER:
take care, this will erase all data on phone. I'm not responsible for any data loss. Follow the instructions on your own risk!

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You updated to ZUI 3.5 using https://forum.xda-developers.com/zu...-to-zui-z2-t3928693/post79493369#post79493369 ? Congrats!

Once you updated to ZUI 3.5 you don't need to get unlock_bootloader.img anymore.

To activate developer option click 7 times on ZUI version under settings - system - about:

-

-


Once you did that you get developer options in settings - system:


Click on it and activate the options OEM unlocking and USB debugging


You can accept the following warning:


Now:

1. Setup ADB and Fastboot on your PC. (can be found here as well: https://forum.xda-developers.com/showthread.php?t=2317790)
   
2. Connect your Lenovo ZUK phone to the PC.
   └ If you get a prompt on phone’s screen to Allow USB debugging, tap OK.
   
3. Open a command window inside the folder where you saved your adb and fastboot install (I suggest using C:\ZUK). To do this, open the folder and then “Shift + Right click” on any empty white-space inside the folder and select “Open command window here” from the context menu.
   
4. Once command window is open, issue the following command to boot device into bootloader mode:
   adb reboot bootloader
   
5. Once in bootloader mode, issue the following command to unlock the device:
   fastboot -i 0x2b4c oem unlock-go
   └ You’ll see the following output:
   ...
   OKAY [ 0.041s]
   finished. total time: 0.041s
   
6. Now phone will reboot. Let the reboot finish completely. Then do "adb reboot bootloader" again.
   
7. now flashing twrp. Download latest twrp version here: https://twrp.me/zuk/zukz2row.html
8. Make sure the downloaded twrp version is located in adb directory as well. Rename it into twrp.img. Then in command prompt type:
   fastboot flash recovery twrp.img
   (if your device is not recognized check hardware manager for driver. You may use fastboot -i 0x2b4c flash recovery twrp.img instead)
9. Reboot your phone to system using the following command:
   fastboot reboot

That's it. You unlocked bootloader and flashed twrp.

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[vlgyneco]

Hello,
I have done evreything as you described in your "howto"
I have now unlock bootloader and TWRP installed. Each time I try to flash a custom rom I have "fail to mount /vendor (invalid argument)..." error.
Still the custom rom I have tried to flash were recent Pie roms so factory to vendor problem should not be the problem.
I think there is somethig here that I did not understood
Can someone help me please?
Thank you

 

[lukmun]

fastboot does not accept the option -i

Thanks for the detailed description.

DISCLAIMER:
take care, this will erase all data on phone. I'm not responsible for any data loss. Follow the instructions on your own risk!

---------------------------------------

• 
  
  5. Once in bootloader mode, issue the following command to unlock the device:
  fastboot -i 0x2b4c oem unlock-go
  └ You’ll see the following output:
  ...
  OKAY [ 0.041s]
  finished. total time: 0.041s
  
  
  --------------------------------------------------------------------

• 
  I am on step 5 with fastboot oem unlock-go. However, it sas "fastboot: unknown option -i"
  What may be the issue?
  
  My phone is zuk z2 pro (z2121)
  ZUI 3.5.3165
  Android 8.0.0
  Android patchdate: 5.02.2018
  
  usb debugging is active
  oem unlock is also done
  
  
  "adb devices" shows me the device. I can also change into bootlaoder using the command "adb reboot bootloader". The phone is connected via
  I am stuck and the phone still has the chinese rom, I cannot seem to proceed. Thanks for any pointers.