[Lenovo P2 Guides, News, & Discussion] medwatt:
USB Drivers, Root, Custom Recoveries + Stock Recoveries

USB Drivers

Lenovo USB driver 1.1.34

Qualcomm USB driver 2.2.0.0

Unlocking the Bootloader

The bootloader must be unlocked before any modding can be done on the P2. Please be aware that unlocking the bootloader voids your warranty and formats your data partition (don't forget to backup important files). Unlocking the bootloader on the P2a42 or the P2c72 running the P2a42 firmware is a simple process.

Go to Settings > About phone > Tap 7 times on Build number > Go back > Enter Developer options > Enable OEM unlocking

Accept the terms that you understand that you're voiding your warranty by choosing to unlock your bootloader

Login with your Lenovo account (if you already have one) or create a new one

Wait for 14 days. A countdown timer will begin that is specifically associated with your device.

After the waiting period, go back to OEM unlocking so that the Lenovo servers can toggle the bootloader unlock switch.

At this point you must have installed the Lenovo USB drivers and Minimal ADB Fastboot on your Windows computer.

Shut down the phone. Enter into fastboot mode by holding Vol Down + Power Button until the screen turns on.

Connect the P2 to your computer and open Minimal ADB Fastboot.

Type: fastboot oem unlock

Recoveries

TWRP 3.2.1-0 (latest custom recovery)

Stock Recovery for Android 6

Stock Recovery for Android 7

If you're going to be installing custom ROMs, it is better to replace the stock recovery with TWRP. Check this page for more information or the latest updates. The procedure below works for both the P2a42 and the P2c72 running the P2a42 firmware.

Rename the TWRP file to twrp.img and move it to both the root of the internal storage of your P2 and the folder where Minimal ADB Fastboot is installed (usually C:\Program Files (x86)\Minimal ADB and Fastboot).

Boot the P2 into fastboot mode.

Open Minimal ADB Fastboot and type : fastboot boot twrp.img

Inside TWRP, choose Install > Install Image > Look for twrp.img > Select recovery > Slide to install.

TWRP will now be installed over the stock recovery. At this point, it makes sense to do a full backup of your partitions. Backup everything except System Image and Cache. In the event you want to return to stock recovery, either restore only the recovery from the Restore menu in TWRP, if you had saved a backup, or flash it as in step 4 above. You should download the stock recovery for the Android version installed on your P2.

Rooting

Files for Magisk method

Files for SuperSU method

The methods described here are only applicable for the P2 running on stock Android 7. Check this post for more details or instructions on how to root the P2 on stock Android 6.

There are basically two methods that can give you super user privileges on the P2. If you have apps that won't allow you to use them if your device is rooted (such as Android Pay), then the Magisk method is for you. This method roots your device without modifying Android's system partition at all. This means that fewer of Android's built-in security measures need to be bypassed in order to gain root access. At the moment, for the Magisk method to work, you need to format the data partition to EXT4. This will obviously erase all your files; so, backup important files before going ahead with it. Download the latest version of Magisk from the link above and move the zip file to the P2's internal storage.

Shut down. Boot into TWRP.

In TWRP, select Wipe > Advanced Wipe > Select Data > Repair or Change File System > Change File System > Select EXT4

Go back to the main menu: Select Install > Look for Magisk-vx.y.zip > Slide to install.

There's also another method you can root the P2 with, but this method is deprecated; it is advisable to use Magisk to provide root privileges as described above. Rooting via the SuperSU method is only presented here for the sake of reference.

You will find two files in the "Files for SuperSU method" linked above.

Install the me.phh.superuser.apk file.

Move the superuser-r259.zip file to the root of the P2's the internal storage.

Shut down. Boot into TWRP.

Select Install > Look for superuser-r259.zip > Slide to install.