How to make a app system on Android: all methods with explanations

Converting a regular application into system on Android opens up new opportunities for the user: autostart after reboot, protection against deletion, access to extended permissions. However, this process requires understanding the internal mechanisms of the operating system and is fraught with risks. Depending on the version Android and root status, the methods will vary.

Many users mistakenly believe that system applications work faster or consume fewer resources. In fact, their key difference is integration with the OS kernel at the level of rights and priorities. For example, the system application com.android.phone is responsible for phone calls and cannot be deleted without serious consequences. In this article, we will look at legal and technical ways to achieve a similar status for third-party apps.

It is important to understand that smartphone manufacturers (for example, Samsung, Xiaomi, Google) are actively fighting against modification of the system partition. Starting from Android 10, restrictions have tightened: sections /system and /vendor became read-only even with root. This complicates the process, but does not make it impossible.

Before you begin, answer this question: do you really need a system application? Perhaps autostart via ADB, assigning an application as a device administrator or using Work Profilewill solve your problem. These methods are less risky and do not require intervention in system files.

What is a system application and why do you need it

System applications - these are apps installed to the section /system/app or /system/priv-app at the stage of flashing the device. They have a number of unique properties:

• 🔒 Deletion protection: cannot be uninstalled without root or special tools.
• 🔄 Automatic launch: start with the system, even if the user did not open them.
• 🛡️ Extended permissions: can access functions that are not available to regular applications (for example, managing SIM cards).
• 📱 Priority in RAM: are less likely to be killed by the system when there is insufficient memory.

Typical examples: com.android.settings (Settings), com.google.android.gm (Gmail in Google firmware), com.samsung.android.messaging (Messages on Samsung). However, not all “built-in” applications are system ones - some are simply pre-installed by the manufacturer in the section /data/app.

Why should an ordinary user make an application system? Here are the common scenarios:

• 🔐 Protection against accidental deletion (for example, for corporate applications).
• ⚡ Startup acceleration of critical utilities (for example, VPN or antivirus).
• 📵 Bypassing restrictions (for example, for ad blockers that need advanced rights).
• 🤖 Task automation without user intervention (for example, for monitoring services).

⚠️ Attention: Turning an application into system may violate security policy Google Play Protect. Some banking applications (for example, SberBank Online or Tinkoff) may block work on devices with a modified system.

Preparing the device: what you need to know before beginning

Before you begin modifying the system, complete the required preparatory steps:

1. Create a backup copy of your data. Use Titanium Backup (for root) or built-in Android tools (Settings → System → Backup). Pay special attention to:

- Contacts and SMS

- Photo/video in DCIM i Pictures

- Saved passwords in Google Smart Lock

2. Check the Android version and device model:

- Go to Settings → About phone

- Write down Android version (for example, 13) and build number (for example, TP1A.220624.014)

- Find out the chipset manufacturer (for example, Qualcomm Snapdragon or Mediatek Helio)

3. Unlock the bootloaderif it is locked. To do this:

- Activate Developer options (click 7 times on Build number settings)

- Enable OEM Unlock in Settings → System → For Developers

- Connect the device to the PC and run the command:

fastboot flashing unlock

⚠️ Attention: Unlocking The bootloader will reset all data on the device to factory settings! On some devices (for example Huawei or Xiaomi) this requires an official unlock code.

4. Install the necessary tools on your PC:

- ADB and Fastboot (part Android SDK Platform-Tools)

- Drivers for your device (for example, Samsung USB Driver or Mediatek VCOM)

- A app for working with system partitions: TWRP (custom recovery) or Magisk (for root)

Method 1: Installing a system application without root (via ADB)

This method is suitable for devices without root access, but requires an unlocked bootloader and support ADB. It works on most devices with Android 8.0–12.0, but may be blocked on some firmware (for example, MIUI or One UI).

Action algorithm:

1. Connect the device to the PC and activate USB debugging in Settings → System → For developers.
2. Open the command line in the folder with ADB and check the connection:

   adb devices

   Your device should appear with the status device.

3. Download the APK file of the application that you want to make system (for example, Greenify.apk).
4. Move the APK to the system partition:

   adb push Greenify.apk /sdcard/
   adb shell
   su
   mount -o rw,remount /system
   cp /sdcard/Greenify.apk /system/priv-app/
   chmod 644 /system/priv-app/Greenify.apk
   reboot

If command mount -o rw,remount /system gives an error read-only file system, which means your firmware is blocking writing to the system partition. In this case, you will need a custom kernel or Magisk.

Downloaded the official ADB from the Google website

USB debugging is enabled on the phone

The device is detected in adb devices

There is a data backup

APK file of the application has been checked for viruses-->

Method limitations:

- On Android 13+ the system partition is protected AVB (Android Verified Boot), and the modification will result in a loading error.

- Some applications (for example, Google Play Services) will not work correctly when manually installed in /system.

- After updating the OS, system applications may be removed.

Method 2: Use Magisk (for devices with root)

Magisk is a tool for obtaining root access that allows you to modify system partitions without changing the partitions themselves (due to the mechanism systemless root). This method works on most modern devices, including those where writing to the /system.

Step-by-step guide:

1. Install Magisk via TWRP or a boot image patch is blocked (instructions are available at XDA Developers).
2. Download the module App Systemizer for Magisk (available in the repository Magisk Modules).
3. Activate the module in the application Magisk and reboot the device.
4. Open App Systemizer, select the desired application from the list and click Systemize.
5. Confirm the action and wait for the reboot.

Advantages of the method:

- Does not require direct entry to /system (works through call interception).

- Compatible with Android 10–14 (including devices with Dynamic Partitions).

- Easy to rollback changes via Magisk Manager.

Disadvantages:

- Requires an unlocked bootloader and installed Magisk.

- Some applications (for example, banking) may detect Magisk and block operation.

Method 3: Manual editing of the firmware (for experienced users)

This method is suitable for enthusiasts who are ready to assemble their own firmware. It requires knowledge of working with Android Image Kitchen or Android Kitchen, as well as an understanding of the structure. system.img.

What you will need:

- Downloaded firmware for your model (for example, stock ROM from the manufacturer).

- Tools for unpacking/packing images: simg2img, img2simg, ext4_unpacker.

- Knowledge of the command line Linux (or WSL in Windows).

Modification process:

1. Unpack the firmware (usually a file system.img.ext4 or system_new.img).
2. Mount the image into a virtual folder:

   sudo mount -t ext4 system.img /mnt/system

3. Copy the APK file to /mnt/system/priv-app/ and set the correct rights:

   sudo chmod 644 /mnt/system/priv-app/YourApp.apk
   sudo chown 0:0 /mnt/system/priv-app/YourApp.apk

4. Unmount the image and rebuild it:

   sudo umount /mnt/system
   img2simg system.img system_new.img

5. Flash the modified system_new.img via fastboot or TWRP.

⚠️ Attention: Incorrect image assembly can lead to briku the device (complete inoperability). Always check the checksums (sha256sum) after modification.

When this method is justified:

- You are creating custom firmware for personal use.

- You need to integrate the application into the firmware for mass deployment (for example, in a corporate environment).

- The manufacturer has blocked all other methods (for example, on Android Go devices).

Risks and how to minimize them

Any intervention in the system partition is fraught with consequences. Here are the main risks and ways to avoid them:

Additional precautions:

- Before modification, check the compatibility of the firmware with your model on the forums (XDA, 4PDA).

- Do not install system applications from unknown sources - this may lead to data leakage.

- If you use Magisk, regularly update it and modules via Magisk Manager.

fastboot flash system system.img
fastboot reboot

Alternative ways to achieve a similar result

If turning an application into a system one seems too risky, consider alternatives:

1. Assigning an application as a device administrator:

- Go in Settings → Security → Device administrators

- Activate the desired application (for example, Cerberus or Bitdefender)

- This will give it rights to lock the screen, reset the password and protect against deletion.

2. Use Work Profile:

- Applications in the work profile (Android for Work) have extended rights and are isolated from the main system.

- Settings: Settings → Accounts → Add a worker profile.

3. Autostart via ADB:

- Disable battery optimization for the application:

adb shell dumpsys deviceidle whitelist +com.your.app

adb shell cmd package set-home-activity com.your.app/.MainActivity