Xiaomi Mi 8 firmware: from unlocking to installing a custom system

The Xiaomi Mi 8, based on the flagship Snapdragon 845 processor, is still a popular device due to its excellent balance of performance and price. However, over time, official support for the model ceases to be available and users stop receiving security updates or new Android features. It is at this point that the question arises of manually installing a fresher version of the operating system or switching to custom builds such as LineageOS or Pixel Experience.

Before you start taking action, you need to be clear about the risks. Any interference with the software code of the device carries the potential threat of turning the device into a “brick” if you do not follow the sequence of operations. In this article, we will discuss in detail how to prepare the Xiaomi Mi 8 for flashing, what tools will be required and how to avoid critical errors at each stage.

It's worth noting that the Global or China firmware process can be different in terms of region compatibility, and we'll look at a generic method that works for most modifications, including NFC and non-NFC versions, and your job is to read each step carefully and not miss the preparatory steps, because they determine the success of the entire operation.

Preparation of the device and necessary tools

Start with a thorough preparation of the workplace and the smartphone itself. You will need a Windows computer (preferably version 10 or 11), a working one. USB-cable, preferably original or certified, providing stable data transfer. All available official updates to the current version must be installed on the phone to avoid loader version conflicts.

The critical step is to create a full backup of all data. When unlocking the bootloader, which is a prerequisite for installing a custom TWRP recavator, the internal memory of the device will be completely cleared. Save contacts, photos and documents to the cloud or to an external medium, so that important information is not lost irretrievably.

You'll need to download specialized software to work, first of all, the Mi Unlock Tool, the official unlock utility, and the ADB and Fastboot drivers. Without properly installed drivers, the computer simply won't see the smartphone in the right mode, and all commands will be ignored by the system.

⚠️ Warning: Make sure that the Mi Account linked to the phone was created at least 7 days (168 hours) ago. Otherwise, the unlock utility will give an error and require a wait, interrupting the process at the start.

Unlocking the bootloader (Bootloader)

The Bootloader in Xiaomi devices is locked by default to protect the system from unsanctioned changes. To flash custom recavers or third-party firmware, it must be unlocked. This process will irreversibly delete all data from the device, so a repeated reminder of the backup here will not be superfluous.

To start, activate Developer Mode. Go to Settings → About Phone and quickly click 7 times on MIUI Version. After you have become a developer, go to Additional → For Developers. Here you need to find the Mi Unlock Status and link your account, and enable the Factory Unlock and USB Debugging options.

Now, connect your phone to your PC when it's off, holding the Volume Down and Power buttons simultaneously until the Fastboot logo appears. Launch the Mi Unlock Tool, log in to your account and click Unlock. If the link is successful and the wait period has expired, the process will take a few seconds.

Once successfully unlocked, the device will automatically restart. Check for the unlocked logo under the Mi logo when turned on - this confirms that the bootloader is open and ready for further manipulation of the software.

Install TWRP Recovery via Fastboot

Standard recovery does not allow you to install modified firmware, so it is replaced with TWRP (Team Win Recovery Project). For Xiaomi Mi 8 (codename dipper), you need to download the current image of.img from the official developer website. Make sure that the file is designed specifically for your model, as firmware from another device can damage the display or touchscreen.

Translate the smartphone to Fastboot mode (buttons Volume Down) + Power) and connect to your computer. Open the command line or PowerShell in the folder with installed ADB Enter a connection check command:

fastboot devices

If you see the serial number of the device, then the connection is established. Now enter the command to temporarily load the recaveri (without writing in memory):

fastboot boot twrp-3.x.x.x-dipper.img

After the command, the phone restarts to the interface. TWRP. If you are planning to just smear ZIP-archive, you can operate from this mode, but to save the Recovery after rebooting, you need to flash it permanently, selecting from the menu. TWRP point → Install Image and specify the same file by selecting the Recovery section.

⚠️ Note: At the first loading in TWRP If you don't need superuser rights, be sure to click "Do Not Install" or the banking applications may stop working.

Firmware Process: Global, China and Custom

There are two main ways to install a new system: through Recovery (in.zip format) and through Fastboot (in.tgz format), the first method is easier and safer for beginners, the second allows you to completely clear the sections and change the region (for example, from China to Global).

For firmware through TWRP copy the firmware file to internal memory or SD-In the Recavator menu, select Wipe. → Advanced Wipe and check out Dalvik sections / ART Cache, Cache and System. Don't touch the Data and Internal Storage sections if you want to save files (although a clean installation is recommended). After cleaning, click Install, select the archive and confirm the swipe action.

If you use the Fastboot method for full flashing, you'll need the Mi Flash Tool utility. Unpack the firmware archive (make sure the path doesn't contain Cyrillic), put the phone into Fastboot mode and plug it into your PC. In the Mi Flash Tool, select the path to the folder, clean all firmware mode (full clean) and press the Flash button. The process will take 200 to 600 seconds.

It is important to understand that when you change region (for example, Global firmware to a device with a Chinese bootloader), you may have problems with encryption or NFC operation.

Solving Typical Errors and Problems

There are a number of errors that can occur in the Xiaomi Mi 8 firmware process, and one of the most common is the Error 7 when installed via TWRP. This means that the install script checks the device model and finds no matches, so you can either use a firmware specifically labeled "Universal" or designed specifically for dipper, or edit the updater-script file, removing the model check.

Another common problem is hanging on the Mi logo (Bootloop).If after installing the firmware, the phone restarts endlessly, try making Wipe Data/Factory Reset right in the Recovery menu. Often the remnants of the old system conflict with the new one, and a complete cleanup of the user partition solves the problem.

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If the phone goes into an endless reboot after installing Magisk, boot to TWRP, go to /data/adb/modules folder, and delete the folder with the name of the module that caused the conflict.

Users also face a situation where the computer does not see the phone in Fastboot mode. In Windows Device Manager, this can appear as "Android" with a yellow exclamation mark. Solution: manually update the driver by pointing the path to the folder with Xiaomi or Google USB Driver drivers.

⚠️ Warning: Never interrupt the Fastboot firmware process by pulling the cable out.This is guaranteed to damage the boot partition and require complex recovery through the Fastboot. EDL-Authorized account mode.

First start and initial setup

Once the firmware is successfully installed, the device will restart. The first run can take up to 5-10 minutes as the system optimizes apps and creates cache. Don't panic if the screen is lit with the logo for a long time - this is normal behavior for Android after a clean installation.

When you first set up, the system may request confirmation of a Google account that was previously synced (FRP protection). Enter your details. If you have changed your firmware region, pay attention to the date and time settings, as well as the operation of Google services, which on the Chinese versions may require additional permission in the app menu.

It is recommended to immediately check the operation of the main modules: camera, microphone, proximity sensor and NFC. Xiaomi Mi 8 is characterized by good optimization, but custom firmware sometimes requires manual calibration of sensors through the engineering menu (code # # #6484##).

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Successful firmware is not only about installing a file, but also checking the operability of all hardware modules in the first minutes of use.

Now your Xiaomi Mi 8 is equipped with a fresh operating system, check security updates regularly and back up important data to ensure that the recovery process takes a minimum of time in the future.