The world of mobile operating systems often seems closed, where the user is limited to what the device manufacturer has provided. However, the ecosystem Android is unique in its openness, allowing enthusiasts to go beyond standard restrictions. Installing an alternative operating system is a process that can give a second life to an old smartphone or expand the functionality of a new gadget by removing unnecessary software and limitations.
Before you begin, it is important to realize that replacing the stock firmware with a custom one (for example, LineageOS or Pixel Experience) requires technical training and an understanding of the risks. This is not just a change of wallpaper, but a deep modification of the system memory section. If you are willing to take the time to learn the process and are not afraid of potential loss of warranty, then this path will open up new horizons of possibilities for you.
In this article we will analyze in detail all the stages: from unlocking the bootloader to the first boot in a new environment. We will touch on issues of compatibility, finding the necessary files and restoring the device in case of errors. Remember that the procedure for installing another OS irreversibly erases all user data from the internal drive. Therefore, creating a backup copy is the first and most important step that cannot be ignored.
Hardware preparation and selection firmware
The success of the operation depends 90% on proper preparation. You will need not only the smartphone itself, but also a computer with a stable Internet connection, as well as a high-quality USB cable. Do not use cheap charging cables, as they may not support data transfer, which will lead to a loss of communication at a critical moment in the firmware.
The first step is to determine the exact model of your device. The name on the box may differ from the actual model code used in the development community. You can find it out in your phone settings or using special applications like CPU-Z. It is by this code that you will search for compatible software.
There are many options for alternative systems, each of which has its own goals. Some focus on maximum performance, others on privacy or visual aesthetics. The choice depends on your personal preferences and hardware characteristics.
- 🚀 LineageOS —the most popular and stable firmware that supports a huge number of devices.
- 🎨 Pixel Experience —turns any phone into an analogue of a Google Pixel with a clean interface.
- 🛡️ /e/OS —an operating system focused on complete de-Googleization and data privacy.
- ⚡ crDroid —offers deep possibilities for customizing the interface and system settings.
You should download system images (.img or .zip) exclusively from official project sites or trusted forums, such as XDA Developers. Files from third-party file hosting services may contain malicious code or be damaged, which will make the device unusable.
⚠️ Attention! Make sure that the downloaded firmware is intended specifically for your model (codename). Installing a version for another device is guaranteed to “brick” the smartphone.
Unlocking the bootloader
A bootloader is a app that runs before the operating system and verifies the digital signatures of all loaded components. By default, it is locked by manufacturers to protect the device from unauthorized changes. Installing another OS is not possible without removing this lock.
The unlocking procedure differs for different brands. For devices Google Pixel i OnePlus this is done through a simple command in Fastboot mode. For Xiaomi requires a wait of 3 to 7 days after linking your account in a special application Mi Unlock. Devices Samsung require switching a special flag in boot mode and confirming the action with the volume buttons.
It is important to understand that unlocking the bootloader often entails triggering the counter Knnox (on Samsung) or loss of warranty. In addition, on many modern smartphones, after this procedure, applications that use protection stop working Widevine L1, which reduces the quality of video playback in streaming services to standard resolution.
fastboot flashing unlockThis command is standard for many devices based on Qualcomm chipsets when operating in the fastbootmode. However, before entering it, the phone will go into factory reset mode, deleting all data. Be prepared for this.
What is Fastboot mode?
This is a data exchange protocol that allows you to interact with the device directly via USB, bypassing the operating system. In this mode, you can write memory partitions, unlock the bootloader and launch recovery images.
Installing custom recovery (TWRP)
The stock recovery menu (Stock Recovery) has limited functionality and allows you to install only updates signed by the manufacturer. To install a third-party OS, we will need a custom recovery, the most popular of which is TWRP (Team Win Recovery Project).
TWRP provides a touch interface, the ability to create full system backups (Nandroid backup), work with the file system and install unsigned zip archives. The recovery image usually has an extension .img and is selected strictly for a specific phone model.
The installation process most often occurs through a computer using the utility adb i fastboot. After connecting the phone in bootloader mode, the command to flash the image to the recovery partition is executed. On some devices, for example, with processors MediaTek, the procedure may differ and require the use of specialized software like SP Flash Tool.
fastboot flash recovery twrp-3.7.0-image_device.imgAfter successful recording, it is important to immediately reboot into recovery mode so that the installed image is not overwritten by the system at the first start. This is usually done with a key combination Volume Down + Power immediately after the screen turns off.
☑️ Ready to install TWRP
Installing the new operating system
When all the preparatory stages have been completed and the phone is loaded into the environment TWRP, the main stage begins. The first step is to completely clear the data, since the file system of the new firmware may differ from the old one, which will lead to conflicts and errors.
In the recovery menu, select Wipe, then Advanced Wipe. Mark sections Dalvik / ART Cache, System, Data and Cache. The Internal Storage section does not need to be touched if you plan to install the firmware from a memory card or internal storage, but it is better to transfer the installation file to your computer in advance.
After cleaning, return to the main menu and select Install. Find the previously downloaded zip archive with the operating system and confirm the installation by swiping. The process may take from 5 to 15 minutes depending on the speed of the device memory.
| Memory section | Purpose | Need to be cleaned? |
|---|---|---|
| System | Stores operating system files | Yes, required |
| Data | User applications and data | Yes, required |
| Cache | Temporary system files | Recommended |
| Internal Storage | Photos, music, documents | No (optional) |
In some cases, especially when upgrading to new versions of Android, installation of an additional package is required GApps (Google Apps), if it is not built into the firmware. This is done immediately after installing the OS itself, without rebooting, using the same principle through the menu Install.
⚠️ Attention! Do not interrupt the installation process and do not disconnect the USB cable until the "Successful" message appears. Interrupting writing to the System section may make the phone unable to boot.
If after installation the system does not boot, try running Wipe Dalvik/ART Cache in TWRP and rebooting again. This often solves problems with the first start.
Configuration and optimization after installation
The first launch of a new operating system usually lasts longer than usual, as applications are optimized and caches are created. Don't panic if the screen stays lit with the logo for more than a minute. After the download is complete, you will be greeted by an initial setup wizard.
The new OS may work differently than the stock one. You'll have to reconfigure Wi-Fi, add accounts, and grant app permissions. Pay attention to the developer settings: sometimes you need to manually activate some features or change the boot order if you have a dual system installed.
To ensure stable operation, it is recommended to install a superuser rights manager if it is not built into the firmware. The most popular solution remains Magisk, which allows you to obtain root access and hide them from banking applications. This is especially true for those who want to maintain the functionality of financial services.
It is also worth checking the operation of the sensors, camera and communication module. In rare cases, drivers may not work correctly in a custom build. If you notice problems with photo quality or loss of network, you should look for fixes on the forum of your firmware developers.
For the first 24 hours after installation, the system is actively learning and optimizing background processes, so increased battery consumption and heating are possible. This is a normal phenomenon.
Possible problems and ways to solve them
Even if you strictly follow the instructions, unforeseen situations may arise. The most common problem is “bootloop”, when the phone endlessly reboots at the startup stage. This may be caused by incompatibility of the GApps version, corruption of the firmware file, or an error when wiping partitions.
If the device does not turn on at all and does not respond to buttons, it may be in "Hard Brick" mode. In such cases, only flashing through the engineering mode (for example, for Qualcomm) using an authorized account or a special box, which is often a paid service in service centers, helps. EDL mode for Qualcomm) using an authorized account or a special box, which is often a paid service at service centers.
Security problems are also not uncommon. Some banking applications refuse to work on devices with an unlocked bootloader. The solution could be a module MagiskHide or using an isolated space, but no one can guarantee full functionality.
- 🔄 Bootlap —boot into TWRP and try installing the firmware again or roll back to the backup.
- 📶 No network —check if the version matches modem (firmware) with firmware requirements.
- 🔋 Fast discharge —uninstall recently installed applications or reset settings to factory settings.
⚠️ Attention! Technical specifications, unlocking methods and firmware availability are constantly changing. Information that is relevant today may be out of date tomorrow. Always check the latest topics on the relevant forums before starting work.
Frequently asked questions (FAQ)
Is it possible to return the factory firmware after installing another OS?
Yes, it is possible. To do this, you need to find the official stock firmware image for your model and install it through recovery mode or a special tool from the manufacturer (for example, Odin for Samsung or Mi Flash for Xiaomi). The unlocked bootloader will remain unlocked unless you explicitly lock it back.
Will Samsung Pay or Google Pay work on custom firmware?
By default, no, since these services check the integrity of the system and the status of the bootloader. However, with the help of root access and_magisk_ modules (for example, Play Integrity Fix), it is often possible to bypass these checks, but this is a game of cat and mouse with security systems, and there is no guarantee.
Do you need_root_ to install LineageOS?
No, installing custom firmware itself does not require root access. Root (superuser rights) is an option that can be turned on or off after installing the system in its settings or through installing the additional Magisk package.
What to do if TWRP does not see the internal memory?
This is a common problem when switching between different versions of Android (for example, from 11 to 13). In new versions, the method of data encryption has changed. The solution is to format the Data partition (not just clear it, but Format Data) inside TWRP by entering the word “yes”. This will delete all data, but make the memory available.