Unlocking bootloader for Lenovo S90 running Android KitKat or Android Lollipop (ROW/CN) - Unlocking bootloader is necessary step for modified Lenovo S90, some advantages unlocking bootloader is root can be install on your device, change official recovery with custom recovery in this case change to TWRP.
Rooting and change custom recovery also give some advantage too, from backing up system until installing custom ROM also. But the process to unlocking bootloader is not easy and sometime can make your device brick, so must be understand the risk before start following this guide.
The author assume that you already know the risk if the process is fail, and there is no warranty if the process is always success 100%.
This guide for educational purpose only, We not responsible if your device bricked after following this tutorial. (DWYOR)
- PC with windows 7 preferably 32 bit, windows 8 and windows 10 not suitable for the guide.
- A good shape USB cable
- We need to install all necessary driver and a flasher program, download below files and begin install it one by one
- Prepare device to ready for the next step.
- Turn on USB debugging, go to System Setting ↦ Developer Options ↦ give check on USB debbugging. If you missing Developer Options then go to System Setting ↦ About Phone ↦ tap 7x until 10x on Build Number
- Put the phone on diagnosis mode :
- Android KitKat 4.4.4 ↦ connect the phone to pc using USB cable then make dial *#*#8899#*#*, then just select OK
- Android Lollipop 5.0.2 ↦ turn off the phone, then turn it on again with hold Volume down + Power button until you can see service menu.
- Look on the device manager on your pc, you should see something like on the picture
click on the image if you want see bigger picture
- S90-ROW_UnLock_BootLoader ↦ for international devices with Android KitKat firmware
- S90-CN_UnLock_BootLoader ↦ for china devices with Android KitKat firmware
- S90-ROW_UnLock_BootLoader_L ↦ for international devices with Android Lollipop firmware
- S90-CN_UnLock_BootLoader_L ↦ for china devices with Android Lollipop firmware
- Download the suitable files for your devices, and extract it contents on any drive. example C:\S90-ROW_UnLock_BootLoader
- Run QFIL flasher program
- On the Programmer Path, select prog_emmc_firehose_8916.mbn from the extracted folder, it will automatically load Search Path
- Click on Load XML.... button and select rawprogram0.xml and patch0.xml also from extracted folder
- Click the Download button and wait the process until it finish, device will automatically reboot.