Many users are faced with a situation where the smartphone manufacturer stops releasing official updates, despite the fact that the device’s hardware is still capable of coping with modern tasks. In such cases, official software images that can be installed manually come to the rescue. This process allows you not only to return the current version custom firmware or official software images that can be installed manually. This process allows you not only to return the current version Android, but also to correct software errors, increase autonomy or gain access to the function root-rights.
The flashing procedure requires care and preparation, since any failures can lead to gadget malfunction. However, if you strictly follow the algorithm of actions and use proven tools, the risk is minimized. Below we will analyze in detail all the stages of preparation and installation methods for the new operating system.
⚠️ Attention: Installing unofficial software will void the official warranty on the device. There is also a risk of losing all user data.
Device preparation and backup
Before starting any manipulations with the system partition, it is critical to save all valuable information. The flashing process is often accompanied by a complete formatting of the internal memory, which makes it impossible to recover deleted files without a first copy. Use cloud services or connect the device to a computer to transfer photos, contacts and messages.
In addition to the data, you need to make sure that it is working properly battery. The battery charge should be at least 60-70 percent, since turning off the power while data is being written to the memory can turn the phone into a “brick”. Also check the integrity of the USB cable through which communication with the PC will be carried out.
To work with advanced installation methods, you will need to activate the hidden capabilities of the system. You need to go to Settings → About phone and click 7 times on the item Build number. After this, in the developer menu you will be able to enable USB debugging.
⚠️ Attention: Menu interfaces may differ depending on the version of the MIUI, OneUI or ColorOS shell. Find the exact paths for your model in the manufacturer's help section.
Selecting the appropriate system image
Finding the correct firmware file is the foundation of a successful update. An incorrectly selected image may not start or cause malfunctions in the communication modules and camera. Files are divided into stock (official) and custom (modified by communities).
Official images usually have an extension .zip for installation via recovery or .tar / .kdz for proprietary utilities on a PC. Custom assemblies, such as LineageOS or Pixel Experienceare distributed in the format .zip and require an unlocked bootloader.
When downloading files, pay attention to the region code and processor model. The firmware for the global version of the smartphone may not be suitable for the Chinese revision due to differences in the radio modules. Always check the file checksum (MD5 or SHA1) to ensure the integrity of the download.
- 🔍 The official website of the manufacturer is the safest source of stock software.
- 🌐 Forum w3bsit3-dns.com or XDA Developers - the best sites for finding custom builds.
- ⚙️ Utilities like Odin or SP Flash Tool require specific drivers and files.
Unlocking the bootloader
Most modern smartphones come with a locked bootloader, which prohibits the installation of system images that are not signed with the manufacturer’s digital key. To install custom recovery and new firmware, this barrier must be removed. The unlocking process differs for different brands.
Devices from Xiaomi require official permission through a special utility Mi Unlock and waiting from 3 to 168 hours after linking the account. Smartphones Google Pixel and OnePlus allow you to unlock the bootloader with a simple command through Fastboot mode without long waits.
It is important to understand that the unlocking procedure initiates a complete data reset (Wipe Data). This is a security measure to prevent information from being stolen from a stolen device by replacing the system. Therefore, a backup must be performed before sending the unlock command.
fastboot oem unlock
fastboot flashing unlock
What happens when unlocking?
When the command is executed, the bootloader erases the userdata and cache partitions. This is necessary to reset digital signatures and prevent conflicts of access rights to encrypted data of the old system.
Installing custom Recovery (TWRP)
The stock recovery menu (Stock Recovery) has extremely limited functionality and allows you to install only updates signed by the manufacturer. To work with custom firmware, you need to install a modified environment, the most popular of which is Team Win Recovery Project (TWRP).
TWRP installation usually occurs through the mode Fastboot. You need to connect the switched off phone to the computer, hold down the combination of buttons (most often Volume down + Power) and enter the command into the console. After successfully recording the recovery image, you cannot immediately reboot into the system, otherwise the stock bootloader may overwrite the modified partition.
Immediately after flashing TWRP, you must perform a combination of buttons to enter recovery mode. In the TWRP menu you will have access to the functions Wipe (cleaning), Install (installing zip archives) and Backup (creating a full copy of partitions). This gives complete control over the file system of the device.
☑️ Checklist before flashing
The process of installing the firmware via Recovery
The main stage of the work takes place inside the TWRP menu. The first step is to clean up the partitions to avoid conflicts between files on the old and new systems. This is called a “Clean Install” and is required when changing the Android version or firmware type.
In the Wipe section, select the formatting of the Dalvik / ART Cache, System, Data and Cache partitions. The Internal Storage section does not need to be touched if the firmware file is located on the internal memory. If the file is on a memory card or a connected PC, formatting the internal memory is also safe.
Next go to menu Install, select the downloaded archive with the firmware and swipe to confirm the installation begins. The process can take anywhere from 2 to 10 minutes depending on the packet size and flash speed. After completion, be sure to clear the Dalvik/ART cache.
| Partition | Destination | Need to be formatted? |
|---|---|---|
| System | Operating system files | Yes (Required) |
| Data | Custom applications and settings | Yes (For a clean installation) |
| Cache | Temporary system files | Yes |
| Dalvik/ART | Application optimization cache | Yes |
| Internal Storage | Photos, music, downloads | No (Dangerous) |
If after installation the firmware does not load (bootloop), try Wipe Data in TWRP again and reflash the GApps package (Google services), if they are not built into image.
Installation via computer (Fastboot and utilities)
Some manufacturers, for example Samsung or Sony, use their own firmware protocols that are not available through standard recovery. For Samsung, a app is used Odinthat works with files of the format .tar.md5 in the mode Download Mode.
For devices on processors MediaTek a utility SP Flash Toolis often used. It allows you to flash the phone even when it is turned off, working directly with the memory controller. This method is more powerful, but more dangerous: an error in the scatter file (scatter-file) can lead to loss of IMEI.
The universal method for many devices remains the use of the command line and tools Android SDK Platform-Tools. The command fastboot flash system image.img allows you to write a partition image directly. This method is often used to return the device to a completely stock state before returning it for service.
⚠️ Attention: Using the SP Flash Tool requires special care. Never press the Format All + Download button without a good reason, this will delete the memory layout and calibration data.
Initial setup and troubleshooting
After successful installation of the new system, the first startup may take longer than usual - from 5 to 15 minutes. This is normal as the system optimizes applications and creates new configuration files. Do not try to reboot the phone at this moment.
If the device is stuck at the logo (bootloop), return to Recovery mode and try resetting the settings (Wipe Data/Factory Reset). If this doesn't help, the firmware file may be damaged or not suitable for your board revision. In this case, you will need to search for another image.
Lack of connection or working Wi-Fi after flashing often indicates a problem with the partition Modem or Radio. In such cases, you need to separately find and flash the modem file corresponding to your version of the base station and region.
A long first boot (10+ minutes) is the norm for new firmware. Interrupting the process at this point may damage system files.
Is it possible to update Android on an old phone?
Yes, if the developer community supports your model. Officially, manufacturers rarely update devices older than 2-3 years, but custom firmware can provide the latest version of Android even on older processors.
What are GApps and do you need to flash them?
GApps (Google Apps) is a package of Google services (Play Market, YouTube, Gmail). They are not built into pure firmware (AOSP) due to licensing restrictions. If you want to use the application store, you need to flash GApps immediately after installing the system.
Is it safe to use banking applications on custom firmware?
No by default, since the integrity of the system (SafetyNet/Play Integrity) is violated. However, there are methods for hiding root access and substituting certificates (for example, through Magisk), which allow you to bypass these checks.
How to return to the official firmware?
To do this, you need to download the full stock image for your model and install it through the manufacturer’s official utility or through Fastboot/Recovery, having previously performed a full wipe data.