Android 9.0 Pie, released in 2018, has become one of the most stable and optimized versions of the operating system from Google. Despite the release of newer versions, many users still strive to install this particular firmware on their devices - be it old smartphones that have not officially received the update, or new devices with inconvenient shells. But is it possible to install Android 9.0 on any smartphoneand what is required for this?

In this article we will look at all possible installation methods, from official updates to custom firmware, and also tell you about the pitfalls that you may encounter. You will learn how to check the compatibility of your device, where to download the necessary files, and what tools you will need for successful firmware. Samsung Galaxy S7, Xiaomi Redmi Note 4 or Huawei P20 Lite —no matter what model you have: we cover universal methods that work on most devices.

We warn you in advance: the process of installing custom firmware is always fraught with risks. From a simple failure to a complete loss of the phone’s functionality - it all depends on your attentiveness and correctness of actions. If you are a beginner, we recommend that you first study the theory and only then move on to practice.

📊 Why do you need Android 9.0?
I want to update my old smartphone
I like the Pie interface
I need Digital Wellbeing features
Experiment with firmware
Other

1. Checking device compatibility with Android 9.0

Before downloading firmware and unlocking the bootloader, you need to make sure that your smartphone technically capable works with Android 9.0. Even if the update has not been officially released, there are custom builds that may work. Here are the key parameters that are worth paying attention to:

  • 📱 Processor and architecture: Android 9.0 requires support for ARMv8-A (64-bit) or x86. Outdated 32-bit chips (for example, in Samsung Galaxy S3 or HTC One M7) are not compatible.
  • 🖥️ RAM volume: Minimum 2 GB for more or less comfortable work. On devices with 1 GB the system will slow down.
  • 🔄 TWRP support: Without custom recovery, it is almost impossible to install unofficial firmware. Check if your model has the latest version Team Win Recovery Project.
  • 🔓 Unlocked bootloader: Manufacturers seem to Huawei, Xiaomi or Sony block the bootloader by default. It will have to be unlocked officially or through exploits.

To check the processor architecture and device model, go to Settings → About phone → Model i Hardware information. Alternatively, you can use applications like CPU-Z or AIDA64. If your chipset belongs to the series Qualcomm Snapdragon 400/600/800, Mediatek Helio P/X or Exynos 7/9, the chances of successful firmware are high.

⚠️ Attention: Some brands (for example Samsung with processors Exynos) may have problems with custom firmware due to proprietary drivers. Before starting work, be sure to study user reviews on the forums XDA Developers or 4PDA for your specific model.

2. Official and unofficial installation methods

There are two main ways to get Android 9.0 on your smartphone: through official update (if available) or through custom firmware. Let's look at both options in more detail.

2.1. Official update (OTA or via PC)

If your smartphone was on the list of devices that received Android 9.0 from the manufacturer, the safest way is to update through standard channels. To do this:

  1. Go to Settings → System → Software update.
  2. Click Check for updates.
  3. If an update is available, download it and follow the instructions on screen.

For some brands (for example, Samsung or LG) you may need to connect to a PC and use proprietary utilities:

- Samsung Smart Switch,

- LG Bridge,

- Xiaomi Mi Flash Tool (for devices Xiaomi/Redmi/POCO).

If there is no official update, but you are sure that it was released for your model, try manual firmware via ADB Sideload or proprietary tools. For example, for Samsung it can be firmware via Odin, and for Xiaomi through Mi Flash.

2.2. Custom firmware (LineageOS, Pixel Experience, AOSP)

If there is no official way, there is an option with unofficial assemblies. The most popular projects:

  • 📱 LineageOS 16 - the most stable and closest to stock Android firmware. Supports many. devices.
  • 🎨 Pixel Experience —firmware with interface and chips from Google Pixel (including Digital Wellbeing).
  • ⚡ Resurrection Remix —custom firmware with a lot of additional settings and themes.
  • 🔧 AOSP Extended —an extended version of stock Android with additional functions.

Where to look for firmware?

- Official website LineageOS (wiki.lineageos.org),

- Forum XDA Developers (forum.xda-developers.com),

- Community 4PDA (4pda.to).

⚠️ Attention: Not all custom firmware is equally stable. Some may have bugs with the camera, mobile network or. sensors. Always read reviews from other users before installation!

Unlock the bootloader|Install TWRP Recovery|Download the firmware and GApps|Make a data backup|Charge the phone at least 70%-->

3. bootloader and TWRP installation

Without an unlocked bootloader and custom recovery, it is impossible to install unofficial firmware. This process differs depending on the manufacturer, but the general scheme looks like this:

3.1. Unlocking the bootloader

For most brands you will need:

  1. Enable USB debugging in Settings → About phone → Build number (press 7 times) → For developers.
  2. Connect the phone to the PC and confirm permission for debugging.
  3. Open the command line (or Terminal on Mac/Linux) and enter: 
    adb reboot bootloader
  4. To unlock, enter the command (for Xiaomi): 
    fastboot oem unlock

    or Google Pixel:

    fastboot flashing unlock

For some manufacturers (for example, Huawei or Honoryou need to obtain unlock code through the official website. For Samsung the process is more complicated - you will need a patched one. data-i="139">and special files Odin and special files BL (bootloader).

3.2. Installing TWRP Recovery

After unlocking the bootloader, you need to flash TWRP a custom recovery that will allow you to install the current firmware. version for your model from the website twrp.me and flash it via fastboot:

fastboot flash recovery twrp-3.7.0-0-your_device.img

fastboot reboot recovery

If after reboot TWRP it does not start, and the stock recovery starts instead, it means that the manufacturer is blocking its replacement. In this case, you will need:

  • Flash TWRP to section boot (for some devices Xiaomi).
  • Use a patched kernel (magisk_patched.img).
  • Disable automatic recovery of stock recovery (on some Samsung).
What to do if TWRP does not see the internal memory?

If, after installing TWRP, the internal memory of the device is not mounted (error "Unable to mount /data"), this means that the data is encrypted. Solutions:

1. Enter the password/pattern in TWRP (if prompted).

2. Format the /data partition manually via Wipe -> Format Data -> enter "yes".

3. Use a newer version of TWRP with FBE (File-Based Encryption) support.

4. Step-by-step guide for installing Android 9.0

When the bootloader unlocked and TWRP installed, you can start flashing. It is important to follow the instructions exactlyto avoid errors. We will consider a universal method that is suitable for most custom firmware.

4.1 Preparing files

You will need:

  • 📁 Firmware in format .zip (for example, lineage-16.0-20231010-nightly-your_device.zip).
  • 🤖 GApps (Google Apps) - a package of Google services (you can download it at opengapps.org). Select version for Android 9.0 and the architecture of your processor (ARM64 or x86).
  • 🔑 Magisk (optional) - to obtain root access (download from github.com/topjohnwu/Magisk).

Transfer the downloaded files to external SD card or to the internal memory of the phone (if visible to TWRP).

4.2. Firmware process via TWRP

Follow this procedure:

  1. Boot into TWRP (hold Power + Volume Up when turned on).
  2. Make a full backup of the current firmware: Backup → Select partitions (Boot, System, Data) → Swipe to Backup.
  3. Reset: 
    Wipe → Advanced Wipe → Check Dalvik, Cache, System, Data → Swipe to Wipe
  4. Install the firmware: 
    Install → Select the firmware ZIP file → Swipe to Confirm Flash
  5. Install GApps (same as firmware).
  6. Install Magisk (if you need root).
  7. Reboot: Reboot → System.

The first launch may take 10-15 minutes —this is normal. Do not interrupt the process!

1. Repeat the installation of the firmware without GApps.

2. Flash the kernel (boot.img) separately via fastboot.

3. Check the compatibility of the firmware with your model on the forum.-->

5. Solving common problems after installation

Even if the firmware was successful, problems may arise and troubleshoot them:

Problem Possible cause Solution
Mobile network does not work No proprietary drivers for the modem Install patch for the modem or flash the stock kernel
The camera gives an error There is no camera HAL support in the firmware Use alternative applications (for example, GCam)
Fast battery drain Unoptimized kernel or background processes Install a supported kernel EAS or calibrate the battery
Google services do not work Incompatible version GApps or missing Google Play Services Reflash GApps or install them manually via ADB
The phone is overheating Incorrect CPU settings or drivers Check the governor settings in kernel or return to the stock firmware

If none of the solutions helped, go to the thematic forum with the error log. To get the log in TWRP, go to Advanced → Copy Log and save it on your PC.

⚠️ Attention: On some devices (for example Samsung Exynos or Huawei Kirin) custom firmware may not support hardware video acceleration. This means that Netflix, YouTube in high definition and games may run with lags Before installation, check if the firmware supports Vulkan and OpenGL ES 3.2.

6. Alternative ways to get Android 9.0

If flashing a custom version seems too risky, there are alternative methods:

  • 🖥️ Android 9.0 emulator on PC: Use Android Studio or Genymotion to launch a virtual device with the desired OS version. Suitable for testing applications.
  • 📱 Firmware via. MultiROM: Allows you to install several OS on one device and select them at boot. Requires kernel support.
  • ⚙️ Ported applications: Some features of Android 9.0 (for example, Digital Wellbeing or Adaptive Battery) can be installed separately via APK on older versions of Android.
  • 🔄 Cloud services: Some apps (such as Shelter or Island) allow you to create an isolated Android 9.0 environment inside your current Android.

If your goal is simply to try out a new interface or specific features, you might want to consider buying a used one smartphone with official support for Android 9.0. For example, Google Pixel 2, OnePlus 6 or Nokia 7 Plus received updates to Android 10-11, but came out of the box with Pie.

💡

Custom firmware is not always the best choice. If you need stability, it is better to stay on the stock version or buy a supported one. device.

7. Risks and how to minimize them

Installing unofficial firmware is always associated with risks. Here are the main ones and ways to reduce them:

  • 💥 Brick (breakage) of the device: If the firmware is interrupted or is incompatible with the hardware, the phone may stop turning on. The only way to recover in this case is firmware via a service cable (for example, EDL for Qualcomm or Download Mode for Samsung).
  • 🔒 Loss of warranty: Unlocking bootloader and custom firmware will void the warranty of most manufacturers.
  • 🛡️ Security issues: Unofficial firmware may contain vulnerabilities or backdoors. Always download files from trusted sources.
  • 📵 Loss of IMEI or serial number: On. Some devices (especially Mediatek) may crash after flashing IMEI. You can restore it through the engineering menu or specialized utilities.

How to reduce risks?

- Make backup all partitions (Boot, System, Data, EFS).

- Use only firmware designed for your exact model (for example, Redmi Note 4X i Redmi Note 4 —different devices!).

- Check the checksums (MD5 or SHA-1) of downloaded files.

- Do not flash on the latest versions bootloader firmware if the firmware is designed for an older one.

If you are not confident in your abilities, it is better to contact experienced users on the forums or to a service center. Some workshops offer custom OS firmware services for a reasonable fee.

FAQ: Frequently asked questions about installing Android 9.0

Is it possible to install Android 9.0 on a smartphone with 1 GB of RAM?

Technically, yes, but the system will work extremely slowly. The minimum requirements for more or less comfortable work are 2 GB RAM and 16 GB ROM. data-i="287">it is recommended to use lightweight firmware like 1 GB It is recommended to use lightweight firmware like LineageOS for MicroG without GApps.

How to return stock firmware, if something goes wrong?

For this you need a backup made in TWRP, or official firmware from the manufacturer. For example, for Samsung these are files with the extension .tar.md5, which are flashed through Odin. For Xiaomi - fastboot firmware via Mi Flash. Instructions for restoring stock firmware are usually available on the forums 4PDA or XDA.

Will Google Pay work after installing custom firmware?

Most likely not. Google Pay requires certified firmware and a locked bootloader. Workarounds (for example, MagiskHide or patches for SafetyNet) may work temporarily, but after updates the applications will stop working. using other payment systems (Samsung Pay, Mir Pay).

Is it possible to upgrade from Android 9.0 to the new version via OTA?

No. Custom firmware does not receive updates over the air. To upgrade to a newer version (for example, Android 10), you need to manually flash the new assembly via TWRP. Some firmware (for example LineageOS) support updating via a built-in updater, but this is not OTA in the classical sense.

Why does Wi-Fi or Bluetooth not work after the firmware?

This is a typical problem when using unofficial firmware, especially on devices with proprietary chips (for example Broadcom or QualcommSolutions:

  • Install a patch with drivers for your model.
  • Flash the stock kernel (boot.img) over the custom one. firmware.
  • Try a different firmware assembly (for example, instead of LineageOS — Resurrection Remix).