[Nokia 4.2 Guides, News, & Discussion] hikari_calyx:
So after you unlock the bootloader successfully, you definitely want to install custom ROM, or at least root the phone, right?

Here's the guide about rooting Nokia 3.2 / 4.2.

This guide could probably work on Nokia 6.2 / 7.2 in the future.

Step 1: Unlock the bootloader

https://xdaforums.com/nokia-4-2/how-to/guide-how-to-unlock-bootloader-nokia-4-2-t3962402

For Nokia 3.2, you'll need to read this as well: https://xdaforums.com/nokia-3-2/how-to/guide-how-to-trigger-nokia-3-2-to-edl-t3962841

Step 2: Acknowledge current slot

You have two methods.

Method 1: After USB debugging enabled, execute this command:

adb shell getprop ro.boot.slot_suffix

Method 2: Under fastboot mode, execute this command:

fastboot getvar current-slot

We assume the current slot is b.

Step 3: Trigger the phone to EDL mode again

There's a hidden command in aboot known as "fastboot reboot-emergency".

However, normal fastboot binary doesn't have that command at all, so we need to compile a binary or hack the binary.

For Windows users, I've provided the fastboot binary that can use this command, and I renamed it to edl-fastboot.exe. You can download it on the attachment below.

For macOS/Linux distro users, I'm afraid you have to fork the source code, edit related content and compile yourself.

So with this special version of fastboot binary, we can boot the phone to EDL mode directly:

edl-fastboot.exe reboot-emergency

Step 4: Use partition manager to dump the partition

If you've came so far when unlocking the bootloader, you have already know the great partition manager.

Still, we assume the COM port number is 8 (COM8).

When the partition list appears, find "boot_b" (or boot_a if the current slot is a), right click on it, choose "Manage Partition Data" and click "Read Data". Then fh_loader binary will dump the boot image to your PC.

For Windows users, it's located at

%AppData%\Qualcomm\QFIL\COMPORT_8

Where %AppData% is actually C:\Users\your_user_name\AppData\Roaming .

The filename looks like this: ReadData_emmc_Lun0_0x3a000_Len65536_DT_07_09_2019_13_55_54.bin

Now close the partition manager, your phone will exit EDL mode and boot normally.

If you're interested in dumping full eMMC storage, you may want to read this: https://xdaforums.com/android/general/guide-how-to-dump-write-storage-t3949588

Step 5: Install Magisk Manager and patch the boot image you dumped

I think everyone who reading this guide knows where to download Magisk Manager.

Copy the boot image you dumped with QFIL to Download directory in your phone's internal storage, and rename it to boot.img for your convenience.

In case you don't know how to patch, read this guide: https://topjohnwu.github.io/Magisk/install.html#boot-image-patching

Step 6: Flash patched boot image and reinstall Magisk for ensurance

After you pulled patched boot image from your phone, reboot your phone to fastboot mode, then execute these commands:

fastboot flash boot magisk_patched.img
fastboot reboot

Note, temporarily boot method introduced back for old A/B devices like Nokia 7 Plus no longer works on Nokia 3.2 / 4.2 - it will boot your phone to Qualcomm 900E mode.

Once your phone booted to normal OS, open Magisk Manager, and reinstall Magisk and required runtime to make the root much more effective.

You may want to read this guide if you want to inherit root along with OTA update: https://topjohnwu.github.io/Magisk/tutorials.html#ota-installation

Extra info about custom rom:

I've tested PHH-Treble GSI on Nokia 4.2 and it made me disappointed.

The vendor compatibility is worse than FIH made Android Phones.

You may want to read this for more details: https://github.com/phhusson/treble_experimentations/wiki/Nokia-4.2

Next preview: Stock firmware reinstallation guide. Note, Nokia 3.2 / 4.2 are not made by FIH, so OST LA no longer works on both devices.

Special thanks:

[MENTION=4470081]topjohnwu[/MENTION] for Magisk

Wingtech for leaking prototype units