In this guide, we will show you three different methods using which you can flash a custom kernel on your Android device. Making a switch from the stock over to the custom kernel has forever been the tech enthusiast’s favorite tweak. After all, when you are getting the option to overclock the device’s CPU/GPU, change the CPU profile, and carry out a slew of under-the-hood changes, then why wouldn’t you be attracted to them?
Likewise, you also get a plethora of Power optimization features [that will help your device in reducing power consumption], numerous Memory management optimizations, I/O tweaks, Battery charging current/percentage limiting [you can limit charging current and battery percentage to prolong battery health, and even Vibration strength customization. So what are you waiting for? Let’s make you aware of numerous methods to flash a custom kernel on your Android device. Follow along.
Table of Contents
How to Flash a Custom Kernel on Android [3 Methods]

Before starting, please take a complete device backup, just to be on the safe side. Droidwin and its members wouldn’t be held responsible in case of a thermonuclear war, your alarm doesn’t wake you up, or if anything happens to your device, and data by performing the below steps.
STEP 1: Backup Boot.img
The custom kernel is flashed in the boot partition. So it is highly recommended to back up your stock boot.img [from the same firmware that is currently installed on your device. You can verify the same from the device’s Build Number].
STEP 2: The Prerequisites
- Download a custom kernel of your choice [supporting KernelSU/KernelSU Next is optional].
- As for this guide, I’m going with the one that supports KernelSU because it will be easier to verify the installation process [via the KernelSU app].
- Once done, download & extract Android SDK Platform Tools.
- Then enable USB Debugging and OEM Unlocking on your device.
- After that, unlock the bootloader on your device.
- Then boot your device to the Fastboot Mode via:
adb reboot bootloader
- Now refer to any one of the three kernel flashing methods given below:
STEP 3A: Flash Custom Kernel Using Fastboot Command
The easiest and most straightforward out of the three kernel flashing methods, this is usually the go-to choice for the masses. Just make sure to rename the custom kernel to kernel.img and transfer it to the platform-tools folder on your PC.
- Type the below command to flash the custom kernel on your device:
fastboot flash boot kernel.img
- After that, type in the below command to boot your device to the OS:
fastboot reboot
STEP 3B: Flash Custom Kernel Via Custom Recovery
If you don’t want to root your device and, more importantly, want to get this job done without using a PC, then this method is just for you [the without PC parameter will only work for you if your device already has a recovery installed and you know the hardware ky combination to boot the device to the recovery].
- First off, transfer the kernel.img file to your device.
- Next up, install a custom recovery onto your device.
- Then boot your device to it via the below command:
adb reboot recovery
- Now go to Install > Install Image > select boot.img.
- Then choose the boot partition and swipe to flash it.
- Finally, head to Reboot > System to boot to the OS.
STEP 3C: Flash Custom Kernel Using a Kernel Flasher App
You can also flash the kernel using a kernel flasher app, however, that would require your device to be rooted beforehand [Magisk | APatch]. Once done, you may then proceed with the below steps [NOTE: as soon as you obtain root via KernelSU, the root via Magisk will be gone, and you can then simply uninstall the Magisk app].
- Install the Kernel Flasher App from GitHub.
- Launch it and grant it the SuperUser request.
- Now, check your active slot via the Slot Suffix.
- Now tap View next to that slot [A in my case].
- Then hit Flash > Flash partition image > boot
- Now, select the kernel file > Reboot > Reboot.
STEP 4: Verify Kernel Installation
Once you have flashed the custom kernel and booted to the OS, it’s now time to verify the result. Since I have flashed a kernel that supports KernelSU, I can simply install the KernelSU app from GitHub and verify the result. So, install and launch it, and verify if it states “Working in <GKI>”.
That’s it. These were the three different methods that should help you root your Nothing Phone 2 via KernelSU. If you have any queries concerning the aforementioned steps, do let us know in the comments. We will get back to you with a solution as soon as possible.