What Is System Ext ROM, NSE ROM, Kernel, Recovery- How To Install

Many of you might have used different custom ROMs on your phone. So you may have heard the term system ext and many of you may be hearing it for the first time. Custom ROMs are mainly used to enhance the performance of the phone. Developers implement their coding skills in these ROMs due to which we get extra performance in these ROMs. The developer’s skills play a significant role in how much performance a custom ROM will deliver.

We have used many different custom ROMs on our phones before which are non-system ext ROM. But now we have come to know about one type of ROM which is known as System Ext ROM. Honestly, it’s not a custom ROM, and you might be wondering what is it.

So in today’s article, we are going to discuss what is system Ext ROM and non-system Ext ROM, what is the difference between these ROMs. We will also discuss what System Ext Kernel and Recovery are, and how we can install them on our devices.

What are System_Ext and Non-System Ext ROM?

Back in the day most of the ROMs we installed were Non-System Ext ROMs. But some devices have reserve partitions, these partitions are used to install additional ROM packages. For all these devices developers have released a type of ROM known as System Ext ROM.

Before going deeper into this topic we need to know about different types of partitions. When we install ROM on our phone, the ROM files are installed in different partitions. Smartphones usually have seven types of partitions.

The number of partitions is different for different phones. But there are seven common partitions in our phone, Data, Boot, Cache, Vendor, Cust, System, and Recovery, now we are introduced to another new partition which is System_Ext. When installing a custom ROM, the ROM files are stored in all these partitions.

For example, the boot partition contains the kernel image file which helps the phone to boot. The system partition contains all necessary files of ROM installed. App data and user data are stored in the data partition. Similarly, all the necessary additional packages are stored in the System Ext partition.

In earlier days, the files of custom ROMs were stored in the system partition, thus the system partition size was reduced a little. But due to the introduction of the System Ext partition, some files are stored in this partition, so the storage space of the system partition is saved a bit and our phones can give better performance than before. Like a computer’s SSD partition, where the operating system is installed on a separate partition rather than on the computer’s hard disk, which makes the computer a bit slightly faster.

Now we will discuss how we can install the Ext ROMs on our phones, but before that, we need to install System Text recovery, but why we have explained it below.

What Is System Ext rom and non system ext rom

What is System Ext Recovery and why should we use it?

The procedure for installing System Ext ROMs is slightly different from Non-System Ext ROMs. A separate recovery is available to install this Ext ROM. This means, that there is a separate Ext recovery present for installing Ext ROMs. We cannot install these ROMs through normal recovery or Non-System Ext recovery.

Because the recoveries we used earlier were Non-System Ext recoveries. Through this recovery, we can’t access the System_Ext partition. That’s why we have to install the latest Ext recovery to install these ROM. If your device system supports Ext partition then you can install these recoveries.

Steps to Install System Ext ROMs on our device?

Then it is clear that you have to use System Ext recovery to install System Ext ROM. Now we will show you how to install these ROMs on your phone. All you need to install these ROM is Unlock Bootloader, System Ext Recovery, and ROM files. You have to follow these steps to install the Ext ROM.

  • First of all, you need to enter the phone recovery, the method of entering the recovery is different for each phone.
  • After entering recovery, from the wipe option, go to advanced wipe and wipe Dalvik, cache, data, system, vendor, and system ext.
  • Then go to install and install the ROM file.
  • Next, install the gapps package if you are using a vanilla build ROM.
  • After everything is done you can install any additional files like root (this is optional)
  • Then select wipe cache and reboot system and wait some time for the device to boot.

You can also read:

What is System Ext Kernel?

Just as we change the ROM in our phone, we also change the kernel in our phone. All the kernels installed by default in ext ROMs are also system ext kernels. Along with Ext ROM, the System Ext kernel has started to be released. But how do we identify which is a System Ext kernel and which is an NSE kernel? How can we install system ext kernel?

As we said earlier, some phones have extra partitions known as reserve partitions. All other packages can be installed here. Earlier custom ROMs were NSE i.e. non-system ext. That’s why the kernel we installed in all these ROMs also had non-system ext. But if you are using a custom ROM that supports system ext then the kernel you install should be system ext. Otherwise your phone is likely to be soft bricked.

But how do you identify if the kernel supports system ext or not?

If your ROM supports System Ext and you want to install a kernel, you need to ask the developer. There is another way to detect whether the kernel system supports ext or not, in this case, you need to carefully look at the file name. If NSE is written to the kernel, it is assumed to be a non-system ext kernel, and if not specified, it is assumed to be a system ext kernel.

Note that this is only for those whose phone and Installed ROM system supports ext partition.

How to install System Ext kernel?

We can install System Ext kernels in the same way we installed NSE kernels. To install System_Ext Kernel you need to follow these steps:

  • You have to go to the custom recovery of the phone, then go to advanced wipe and clear delvic and cache.
  • Then go to the install option and select the system ext kernel file to install.
  • Then reboot the device and wait for the phone to boot.
Note: The system ext kernel should be installed when you have installed a ROM that supports system ext. You must backup the boot file before installing the kernel so that if your device gets stuck in a boot loop, you can restore the boot file and go back to the previous state.


These were full details information about System Ext and NSE ROM. System Ext partition is only supported on some devices. As per our understanding, Poco f1 and Poco x3 Pro support these reserved partitions. Hope we have made you understand the difference between system ext and non-system_ext. If you found the post informative, please share it with your friends, thanks

FAQs System Ext and Non-system ext ROM

What is a system ext ROM?

This is the newly introduced ROM, System Ext ROMs have a partition called System Ext where some of the ROM data is stored.

How do we install the system ext ROMs?

We can install these ROMs in the same way we install non-system ROMs. During installation, we have to wipe system ext partition and we can install these ROMs only through system ext recovery.

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