Since TWRP is unbootable under this build, you have to use patched boot trick to root this phone.
However, only Magisk 17.1 is usable on this build, Magisk 17.2 - 18.0 can't be installed properly.
So I made a custom update channel that fixed to Magisk 17.1 to assist me.
This guide requires unlocked bootloader - still, I won't introduce how to unlock it here, please Google for it.
Here's how to root:
1. Extract the D1C-0-6120-00CN-boot.img from my homebrew firmware written in previous guide, or extract the boot.img from the OTA package.
(Later versions will also provide the patched boot image)
2. Copy this boot.img to Download directory.
3. Install latest Magisk Manager from https://github.com/topjohnwu/Magisk/releases
Remember to allow all the permission after installed.
4. Choose "Left Hamburger Menu" - "Settings" - "Update Channel" - "Custom", and type following URL:
Code:
https://dwz.cn/5I3anBD4
5. Back to Magisk Manager main interface, refresh it and check if latest version changed to 17.1.
Tap "Install" - "Install" - "Patch Boot Image", "Left Hamburger Menu" - "Download" - the boot img you copied.
And wait for the patching procedure complete.
6. Copy patched_boot.img from the Download directory of internal storage to PC.
7. Reboot your phone to fastboot mode and execute following commands:
Code:
.\fastboot reboot-bootloader
.\fastboot boot D:\patched_boot.img
8. Open Magisk Manager, reinstall Magisk 17.1 directly.
9. Reboot your phone and all done.
Is this procedure familiar? Yes, it's the same method used on Nokia 7 Plus. But I wrote this guide to tell you few details that you need to notice.
Hope TWRP can be compiled for D1C-6120.