Xiaomi Mi A1 Firmware via Fastboot: A Complete Guide from Preparation to Installation

Xiaomi Mi A1 is a cult smartphone released in 2017 as part of the Android One program. Despite its age, the device is still popular thanks to its clean Android, powerful hardware and active support for custom firmware. However, over time, official updates have ceased to come out, and users have faced the need for self-flashing - especially if the device began to "brake" or require the installation of a new version of the OS.

Fastboot is one of the most reliable ways to upgrade or restore the Mi A1, but the process requires care. Unlike the recovery method, it installs the firmware directly through the computer, which minimizes the risk of bricking, but imposes strict preparation requirements. In this article, we will examine the entire process Step-by-step, from unlocking the bootloader to installing custom or stock firmware, and consider typical errors and how to solve them.

Why Fastboot and not Recovery?

Xiaomi Mi A1 users have two main ways of firmware: through Fastboot and Recovery (TWRP). Each of them has its pros and cons, but the Fastboot method is often preferred in the following cases:

• 🔧 You need to restore the device after a “soft brick” (for example, after an unsuccessful firmware through the device). TWRP).
• 📦 You need to install official stock firmware from Xiaomi (Fastboot firmware usually contains a full file package, including a bootloader).
• 🔒 The bootloader is locked, and unlocking via Mi Unlock Tool is only possible in Fastboot mode.
• 🛡️ Minimizing risks: with proper execution of commands, the chance to “brick” the device is lower than when working with custom recovery.

However, the method has drawbacks:

• ⚠️ You need an unlocked bootloader (if it is locked, you will have to unlock it first through the Mi Unlock Tool).
• 💻 We need drivers. ADB/Fastboot Minimum command line skills.
• 🔌 The process takes longer than the firmware through TWRP.

If your goal is to install custom firmware (for example, LineageOS or Pixel Experience), then after unlocking the bootloader you can go to the Internet. TWRP sniff ZIP-But first you still have to unlock the bootloader through Fastboot.

Preparation for firmware: what will be needed

Before you start firmware, make sure you have everything you need, and missing at least one component can cause firmware failure or even damage to the device.

Here's the full list:

Pay special attention to the choice of firmware. For the Mi A1, you can:

• 📌 Official Fastboot Firmware from Xiaomi (for example, tissot_global_images_V12.0.2.0.PDHMIXM).
• 📌 Base-based castor firmware AOSP (LineageOS, Pixel Experience, Havoc-OS).
• 📌 Firmware port from other devices (for example, ported) MIUI 12 for Mi A1).

⚠️ Note: If you install an official firmware from Xiaomi, check its region. Global firmware is not suitable for China and vice versa.

Unlock the bootloader on Xiaomi Mi A1

If you have never unlocked the bootloader on your Mi A1, then before you run through Fastboot, you will have to do this. Xiaomi blocks the bootloader by default, and without unlocking, installing custom firmware or even the official Fastboot will not be possible.

The unlocking process includes several stages:

1. Getting permission from Xiaomi via Mi Unlock Tool
2. Linking your Mi Account to your device.
3. Directly unlock through Fastboot.

Important: since 2021, Xiaomi has tightened the unlock rules, now you need to wait 168 hours (7 days) after you link your account to your device.

Step 1: Linking your Mi Account

1. Go to Settings → About Phone → MIUI version and tap 7 times on the line with the version to activate the developer mode.

2. Return to Settings → Additional → For Developers and Enable:

• 🔧 Debugging by USB.
• 🔧 Unlocking OEM (If the option is not available, the bootloader is already unlocked).

3. Connect your phone to your Mi: Settings → Accounts → Mi Account.

Step 2: Unlocking with Mi Unlock Tool

1. Download the Mi Unlock Tool and install it on your computer.

2. Launch the utility and log in to the same Mi Account that is linked to the phone.

3. Transform the Mi A1 to Fastboot mode:

adb reboot bootloader

4. Connect the phone to your computer and in Mi Unlock Tool press Unlock.

⚠️ Note: If the utility gives an error Couldn't unlock or Current account is different from the account info on the device, then the account is not tied correctly.

Once successfully unlocked, the phone will have Unlocked in Fastboot mode, and you can start running the firmware.

Install firmware through Fastboot: step-by-step instructions

When the bootloader is unlocked, you can start running firmware. Consider the process using Xiaomi's official Fastboot firmware. For custom firmware (LineageOS, Pixel Experience), the steps will be similar, but instead of using the same software, the process will be more difficult. flash_all.bat You will need to manually write commands.

Step 1: Preparing the firmware

1. Download Fastboot firmware for Mi A1 (the device's code name is tissot). For example, from the Xiaomi Firmware Updater website.

2. Unpack the archive in a folder with Platform Tools (where adb.exe and fastboot.exe are located).

3. There must be a file inside the archive. flash_all.bat (for Windows or flash_all.sh (for Linux/Mac).

Step 2: Transfer your phone to Fastboot mode

1. Turn off the Mi A1.

2. Press the buttons Loudness down + Power and hold them for 5-10 seconds until the screen with a hare in a hat-eared (Fastboot logo) appears.

3. Connect the phone to the computer.

Step 3: Starting the firmware

1. Open the command prompt in the firmware folder (Shift + right mouse button → “Open command window”).

2.For official firmware Xiaomi do:

flash_all.bat

For custom firmware (like LineageOS), the commands will be different.

fastboot flash boot boot.img


fastboot flash system system.img




fastboot flash vendor vendor.img




fastboot flash dtbo dtbo.img




fastboot reboot

The firmware process will take 5-15 minutes, and when it's done, the phone will automatically restart.

⚠️ Note: If you have been following the Mi A1 If you're stuck on the logo or you're in a bootloop, it means the firmware is not suitable for your model or it's damaged, and you're going to have to do it again with another firmware version.

💡

If the firmware is interrupted with the error remote: partition table doesn't exist, then you are trying to flash the wrong version (for example, firmware for Mi A2). Always check the device code name (tissot for Mi A1).

Typical errors and their solutions

Even with strict adherence to the instructions, errors can occur. Consider the most common problems when running Xiaomi Mi A1 firmware through Fastboot and how to solve them.

If none of these methods worked, try flashing your device through the Mi Flash Tool, Xiaomi's official utility, which automatically identifies the model and installs the right firmware.

💡

The most common mistake when running the Mi A1 firmware is that the firmware version is not the same as the device model. Always check the code name (tissot) and the region (Global/China).

Firmware custom firmware (LineageOS, Pixel Experience)

Xiaomi Mi A1 — one of the most popular devices for installing custom firmware due to an active community on the XDA Developers: If you want to install LineageOS, Pixel Experience or other AOSP-Firmware, the process will be slightly different from the installation of official firmware.

Here are the key steps:

1. Install. TWRP Recovery (Castom Recovery for Firmware) ZIP-archive).
2. Backup the current firmware through TWRP.
3. Sweep through custom firmware and, if necessary, Gapps (Google services).
4. Clear the cache (Wipe → Format Data).

Example of commands for installing TWRP via Fastboot:

fastboot flash recovery twrp-3.7.0_tissot.img


fastboot boot twrp-3.7.0_tissot.img

Then you can load up to the TWRP sniff ZIP-firmware.

⚠️ Note: Some custom firmware (e.g., Pixel Experience) require additional firmware vendor-partition from stock firmware.

Recovery after a failed firmware

If something goes wrong and the Mi A1 stops turning on or hangs on the logo, don't panic. In most cases, the device can be restored.

• 🔄 Hard Reset: Hold the Volume Up + Power for 10 to 15 seconds. If the phone vibrates, release the buttons, the device will restart.
• 📥 Firmware via Mi Flash Tool: download the official firmware and flash it through the Mi Flash Tool (select Clean All option).
• 🔧 Installation TWRP firmware ZIP: If the phone is loaded into Fastboot but not into the system, please click on it. TWRP Install the working firmware through recovery.

If the phone is not responding to buttons and is not detected by the computer, there may be a hardware failure (for example, damage to flash memory), in which case only the service center will help.

FAQ: Frequent questions about the firmware Xiaomi Mi A1