Modification of the Android operating system opens up unlimited possibilities for the user that are not available in standard firmware. You can remove pre-installed bloatware, replace system fonts, change the bootloader logo, or even rebuild the firmware image to install a custom recovery. However, working with system partition requires a deep understanding of the file system architecture and strict adherence to security measures.
Any intervention in the directory structure, such as /system, /vendor or /productcarries the risk of turning the device into "brick". Modern versions of Android, starting from 6.0 and higher, have implemented strict integrity protection mechanisms, such as SELinux and Verified Boot. This means that you won’t be able to simply edit the file - the system will either block the entry or refuse to boot when changes are detected.
In this guide, we will examine in detail the legal and technical ways to modify the system kernel. We will consider both classic methods of obtaining root access, and more advanced options for using systemless modules via Magisk. It is important to understand that each step must be conscious, and a data backup is a prerequisite before starting any manipulations.
Preparing the environment and obtaining superuser rights
The first and most critical step is unlocking the bootloader. Without this procedure, write access to the system partition will be physically blocked at the hardware controller level. The unlocking process varies between manufacturers: Xiaomi requires waiting for 168 hours, while devices Google Pixel or OnePlus allow you to do this instantly via the Fastboot command.
After unlocking, you need to install specialized software to manage privileges. The gold standard of the industry today is Magisk. Unlike the outdated SuperSU, Magisk works on the systemless principle, that is, it does not directly modify files in the /system partition, but replaces them on the fly during boot. This allows you to pass security checks for banking applications and Google Play services.
⚠️ Attention: Unlocking the bootloader on most smartphones will automatically void the manufacturer's warranty. In addition, this procedure initiates a complete reset of all user data (Factory Reset), so be sure to save important photos and contacts in the cloud before starting.
To install superuser rights, you will need a computer with a set of tools installed Platform Tools (ADB and Fastboot). Connect your smartphone in USB debugging mode and run the command adb reboot bootloader, then use fastboot flashing unlock or a similar command specific to your vendor. Only after successfully loading into a system with Magisk installed can you begin editing files.
Toolkit for working with the system partition
Availability Rooting is only half the battle. To directly change files, you need a file manager that can work with administrator rights and set permissions correctly. Regular explorers available on Google Play often do not have access to the root directory or do not know how to correctly mount partitions in read-write (R/W) mode.
One of the most reliable solutions is the application MT Manager or Root Explorer. These tools not only allow you to copy and delete files, but also edit binaries, sign APKs, and change file attributes. When you try to enter the folder /system such an application will ask for confirmation to grant Root access, which is normal behavior.
An alternative, but more complex method is to use the command line through the terminal on the device itself or through ADB on the computer. This method gives maximum control, but requires knowledge of Linux command syntax. An error in one letter when entering a command rm or chmod can lead to critical consequences for the performance of the OS.
Use only proven file managers with an active developer community. Avoid dubious applications that promise to “speed up your phone” by deleting system files - most often this is a scam.
Before you start, make sure that your file manager correctly detects the file system type. Modern devices use ext4 or f2fs, and working with them in recording mode requires proper mounting. Some managers do this automatically, others require manually pressing the “Mount R/W” button in the application settings.
Direct editing of files in the /system section
The classic method of changing system files involves direct intervention in the contents of the section. Most often, users seek to remove unnecessary applications or replace standard ringtones and fonts. To do this, you need to find the target file, make a backup copy of it with a different extension (for example, .bak) and only then replace it.
Particular attention should be paid to access rights. On Linux-like systems, such as Android, each file has an owner, a group, and a set of read, write, and execute permissions. If you replace a system file, but forget to set the correct rights (usually rw-r--r-- or 644 for regular files and 755 for executable scripts), the system may not start the corresponding service.
| File type | Recommended rights (Chmod) | Owner | Group |
|---|---|---|---|
| Application APK | 644 (rw-r--r--) | root | root |
| Libraries (.so) | 644 (rw-r--r--) | root | root |
| Launch scripts (.sh) | 755 (rwxr-xr-x) | root | root |
| Configuration files | 644 (rw-r--r--) | root | shell |
When removing system applications, it is important to remember dependencies. Some services, for example Google Play Services or the system launcher, are critical for the operation of the interface. Removing them will result in an endless reboot (bootloop). Always check on the Internet whether the application is a system critical component or a regular bundle that can be safely deleted.
☑️ Checklist before deleting a file
Using Magisk Modules for safe modification
The modern approach to Android customization has shifted towards the use of modules Magisk. This method is considered more secure, since it does not require direct modification of files in the partition /system. Instead, Magisk creates an overlay layer that replaces the files of the original system with modified versions at the moment the device boots.
The main advantage of this approach is the ability to instantly roll back changes. If an installed module causes conflicts or errors, you can simply disable it in the Magisk Manager menu or remove it, and the system will return to its original state without the need for flashing. This is especially true for devices with an active mechanism Verified Bootthat can block booting when changes are detected in the system partition.
There are thousands of ready-made modules for a variety of tasks: from changing fonts and emoji to global processing of the audio path and unlocking processor frequencies. Installation of the module usually occurs through the Magisk application: just select the ZIP archive with the module, and the installation script will automatically integrate it into the system.
⚠️ Attention: Incompatibility between Magisk versions and the Android version may lead to the module not working or causing a crash. Always check the module requirements and read user comments before installing.
For advanced users, the ability to create their own modules is available. This requires knowledge of the structure of the module ZIP archive, the presence of a file module.prop with metadata and an installation script. Creating your own module allows you to distribute your settings among other enthusiasts without forcing them to manually copy files across directories.
What is an A/B partition system?
Some modern smartphones use an A/B (Seamless Updates) partition scheme. In such devices, the update occurs in the background on an inactive partition. When modifying the system on such devices, you need to be especially careful, since changing files can disrupt the OTA update process or lead to booting from a damaged slot.
Mounting partitions and working via ADB
For those who prefer to work from a computer, Android Debug Bridge (ADB)remains an indispensable tool. The debugging connection allows you to execute commands in the shell environment with superuser rights if the device is Rooted. This gives flexibility not available when working through the phone's GUI.
To access the file system, you must first enter the shell with the command adb shell, and then request elevated privileges via su. You can then use standard Linux utilities for navigation and editing. An important aspect is to mount the partition in write mode, since by default the system partition is mounted read-only (Read-Only).
adb shellsu
mount -o rw,remount /system
After executing the mount command, you can push files from the computer to the phone using the command adb push or edit them directly with text editors. This method is often used to replace system libraries or configuration files that are difficult to change through mobile applications due to process locks.
However, working through ADB requires high concentration. Lack of visual confirmation of actions increases the risk of accidentally deleting critical files. It is recommended to use scripts to automate routine tasks, but before running them, always study the code to understand exactly what actions will be performed.
Using ADB gives maximum control over the system, but requires confident knowledge of the Linux command line. For beginners, it is safer to use graphical file managers with Root access.
Restoring the system after modification errors
Even if all precautions are taken, errors happen. Incorrectly set permissions, deleting a required library, or a version conflict can cause the smartphone to stop booting. In most cases, the device will reboot cyclically, showing the manufacturer's logo, or freeze on the boot animation.
The first step in such a situation is to try to boot into mode Recovery. If you have a custom recovery installed, for example TWRP, you can restore a full system backup (Nandroid Backup) made before starting the experiments. This is the fastest way to bring your phone back to life without losing data if the backup is current.
If there is no custom recovery, you can try to remove the problematic Magisk module through safe mode or a special function to disable modules on boot (usually by holding the volume button). As a last resort, when software methods do not help, the only option left is to flash the device via Fastboot or Download Mode using official firmware images from the manufacturer.
⚠️ Attention: Full flashing (Flash) via a computer, as a rule, completely clears the internal memory of the device. All photos, messages and installed applications will be permanently deleted if you have not made a backup copy in advance.
To prevent such situations, professionals recommend keeping a change log. Record which files have been changed, which commands have been entered, and which modules have been installed. This will allow you to quickly localize the cause of the failure when problems arise and purposefully eliminate it, rather than acting at random.
Frequently asked questions (FAQ)
Is it safe to change system files on modern Android 13-14?
Security depends on the method. Directly editing the /system partition on newer versions of Android is extremely risky due to strict integrity checking (AVB). Using Magisk modules is a much safer option, as it does not violate the integrity of the original partition and allows you to easily roll back changes.
Will I be able to use banking applications after receiving Root?
By default, banking applications do not work on Rooted devices. However, using Magisk with the Zygisk function enabled and the Hide module (or Shamiko) allows you to hide the fact that you have superuser rights from most applications, restoring their functionality.
What to do if the phone went into Bootloop after deleting a file?
You need to boot into Recovery mode. If you have a backup, restore it. If there is no backup, try deleting the last installed Magisk module or the file you last modified using the file manager in Recovery mode (if it supports access to the system partition). In the worst case, a flashing will be required.
Do you need to unlock the bootloader to install Magisk?
Yes, unlocking the bootloader is a prerequisite for installing Magisk and getting full Root access. Without an unlocked bootloader, you will not be able to flash the modified boot.img image, which is necessary for the privilege manager to work.
Is it possible to update the system over the air (OTA) with modified system files?
As a rule, no. The OTA update mechanism checks the checksums of system files. If they are changed, the update will not install or will fail. When using Magisk, the system often masks changes, but to install a major Android update, sometimes you need to temporarily remove Root or return stock.