Installing firmware on Xiaomi Redmi Note 4: from unlock to final setup

The Xiaomi Redmi Note 4 (codenamed mido) remains one of the most popular smartphones for firmware experiments years after its release, and the reasons are obvious: reliable hardware, a vibrant community of developers, and the ability to install both official MIUI builds and custom firmware like LineageOS or Pixel Experience. However, the installation process has nuances that can turn a routine operation into a brick if you step wrong.

This article covers everything from preparing the device and unlocking the bootloader to choosing a firmware method (via Fastboot, Recovery or EDL) and solving common errors. We will discuss what tools you need, how to avoid data loss, and why firmware through informal recovery (such as TWRP) requires a mandatory compatibility check with the Android version. If you are a beginner, follow the instructions consistently; if an experienced user, use the article as a checklist to avoid common errors.

1. Device Preparation: What to Do Before Firmware

The first and most critical stage is preparation, and neglecting it often leads to a Mi Account being blocked, data loss, or even a device being “bricked up” by checking the current firmware version and the status of the bootloader.

To find out the MIUI version and device model:

1. Go to Settings. → The phone.
2. Find the MIUI version and device model (should be Redmi Note 4 or mido).
3. Write down an Android version (like 7.0 Nougat or 6.0 Marshmallow) and it will affect your firmware choices.

Check the status of the loader:

• 🔧 Turn off the phone, then press Volume Down + Power to log into Fastboot.
• 🖥️ Connect the device to a PC and type in the command line: fastboot oem device-info
• 🔍 If the answer is Device unlocked: true, the bootloader is unlocked. If false, you will need to unlock (more about this in the next section).

⚠️ Warning: Firmware on a locked bootloader via Fastboot or Recovery will result in an anti-rollback error and possible device loss. Check the bootloader status by sure!

Also prepare:

• 📱 Backup data (photos, contacts, messages) – the firmware erases internal memory.
• 🔋 Battery charge of at least 60% – interruption of the process due to discharge is fraught with consequences.
• 💻 PC with installed Xiaomi drivers and tools ADB/Fastboot (you can download from the official Android website).
• 📁 The firmware itself (official or custom) is in.zip (for Recovery) or.tgz (for Fastboot).

2 Unlocking the bootloader: a mandatory step for custom firmware

Xiaomi blocks the bootloader on all devices by default, which means that installing custom firmware or even official through Fastboot without unlocking is impossible, the process requires linking the Mi Account to the device and waiting for permission from Xiaomi servers (usually 3-7 days).

Instructions for unlocking:

1. Link your Mi Account to your phone: 📱 Go to Settings → Mi Account and log in. 🔗 Enable sync and confirm device association via SMS.
2. Download Mi Unlock Tool: 🌐 The official utility is available on Xiaomi's website (registration required). ⚠️ Don't use third-party versions - they may contain malicious code.

Run the unlock:

1. Turn off the phone and log in to Fastboot (Loudness down + Power).


2. Connect to the PC and start the Mi Unlock Tool.




3. log in to the same Mi Account as you do on your phone.




4. Press Unlock and wait until it is completed (it may take several attempts).

Important nuances:

• 🕒 Resolution Waiting: After the first attempt to unlock, Xiaomi servers may return an error with an offer to wait (usually 72-168 hours).
• 🔄 Anti-rollback protection: If you have previously flashed your device, check the Anti-Rollback version (ARB). Lowering the firmware version below the current ARB will result in a lock.
• 📵 No SIM- card: At the unlocking stage SIM- card is not required, but Mi Account must be confirmed by phone number.

⚠️ Warning: Unlocking the bootloader resets the device to factory settings! backup ahead. Also, once unlocked, some features (such as Mi Pay or Find Device) may stop working.

Linked to the Mi Account to the device|Download the official Mi Unlock Tool|Phone in Fastboot mode|driver-PC ADB/Fastboot|Backup of data-->

3. firmware selection: official MIUI vs custom builds

The choice of firmware depends not only on the functionality, but also on the stability of the device. Redmi Note 4 supports three types of firmware:

Where to download firmware:

• 🌍 Official MIUI: en.miui.com (choose the Redmi Note 4 or mido version) Xiaomi.EU Forum (firmware with remote bloatware and multilingual support).
• 🛠️ Castom firmware: XDA-Developers Forum (look for a theme for mido) Official project sites (e.g. LineageOS).

Critical moments in the selection:

• 🔢 Android Version: Redmi Note 4 officially supports up to Android 7.0 Nougat (MIUI 11). Castom firmware may offer Android 10/11 but with limitations (e.g., a broken fingerprint sensor).
• 🔄 Anti-Rollback: Check the ARB version in the current firmware (you can find out via Fastboot by fastboot getvar anti command). The new firmware must have ARB not lower than the current one!
• 📦 Firmware type: Fastboot needs a.tgz file, Recovery needs a.zip file. Don't mix it up!

💡

Before downloading custom firmware, check the reviews on the XDA forum. Pay attention to the date of the last update - if the firmware has not been updated for more than a year, it may contain uncorrected bugs.

4. Firmware installation methods: Fastboot, Recovery or EDL

The way you install it depends on the type of firmware and the state of the device. Let's look at three basic methods:

Installation via Fastboot (for official firmware)

Suitable for official MIUI firmware in.tgz format. Requires an unlocked bootloader and PC.

Step-by-step:

1. Unpack the.tgz archive in the folder with Fastboot (where fastboot.exe lies).
2. Turn off your phone and log in to Fastboot (Loudness Down + Power).
3. Connect to the PC and launch the file flash_all.bat (Windows or flash_all.sh (Linux/Mac).
4. Wait until the phone is finished (the phone will reboot automatically).

If the process is interrupted with an error, try:

• 🔄 Delete the flash_all_lock.bat and flash_all_except_data_storage.bat files from the folder, which lock the bootloader.
• 🔧 Manually run the command: fastboot flash all -w (the -w flag will reset the data).

4.2 Installation via Recovery (TWRP or stock)

A universal method for custom firmware and some official (.zip format) requires installed TWRP Recovery.

Instructions:

1. Download TWRP for mido (for example, from the official website).
2. Install it via Fastboot: fastboot flash recovery twrp.img fastboot boot twrp.img
3. In TWRP, run Wipe → Advanced Wipe and mark Dalvik, Cache, Data, System.
4. Press Install, select the firmware file.zip and confirm the installation.

⚠️ Warning: If you set MIUI through TWRP, turn off signature verification in the recovery settings (Settings → Disable DM-Verity).

4.3 Installation via EDL (for "bricks")

Emergency Download Mode (EDL) - the last chance to restore the device if it does not turn on. requires special cable or test points.

Instructions:

• 🔌 Connect your phone to your PC in EDL mode (need a contact-closing cable or a soldering iron for testpoints).
• 🖥️ Use the Mi Flash Tool and.tgz firmware for full flashing.
• ⚠️ The method is risky - if the device fails, it can finally fail.

5. Typical errors and their solutions

Even if you follow the instructions accurately, you can get errors.

Additional advice:

• 🔄 If the phone loads into Fastboot after firmware, try the command: fastboot continue
• 📵 If the screen is black but the phone is vibrating, the display may not be working. Connect to a PC and check through ADB: adb shell
• 🔋 If the device is discharged during firmware, charge it for 10-15 minutes, then repeat the process.

💡

The most common mistake is ignoring the Anti-Rollback (ARB) version. Always check it before you run firmware, especially if you switch from custom firmware to official firmware.

6.After installation: initial setup and optimization

Once the firmware is successful, the device requires initial setup, and a few tips for optimal operation:

For the official MIUI:

• 📱 When you first turn on, skip the Mi Account binding if you don't want to receive ads.
• 🔧 Disable unnecessary services: Go to Settings → Memory → Autostart and disable Autostart for unnecessary applications. In Settings → Mi → Mi Cloud account, turn off sync if you are not using.
• 🚫 Remove bloatware (preinstalled applications) via ADB: adb shell pm uninstall -k --user 0 com.miui.weather2 (replace com.miui.weather2 with the desired application package).

For custom firmware:

• 🔒 Set up root access (if required) through Magisk.
• 📡 Check the modules: Camera: Set GCam for improved shooting. IR- Blaster: Download Mi Remote from APKMirror.
• 🔋 Optimize the battery: Turn on Settings → Battery → Power Saving Mode. Turn off background activity for social media.

Useful applications after firmware:

• 🛡️ Magisk is for root rights and modules.
• 🔍 Titanium Backup – Application backup (requires root)
• 📊 CPU-Z — Checking the iron and temperature.

7. How to return the official firmware with custom

If custom firmware was unstable or you want to return the warranty, you can roll back to the official MIUI. The process is almost identical to the installation, but there are nuances:

Instructions:

1. Download stable MIUI for mido in Fastboot format (.tgz).
2. Unpack the archive and delete the flash_all_lock.bat files (they will block the bootloader).
3. Fastboot: Fastboot Flash All -w
4. After restarting, set the device as new.

Important points:

• 🔄 If you have installed TWRP, it must be removed, otherwise the official OTA- updates will not work.
• 🔒 To return the bootloader lock (for guarantee), use the command: fastboot oem lock ⚠️ This will reset the device and may result in locking if the firmware is unofficial!
• 📵 If after firmware the phone requests a Mi Account that was previously linked, you will need to enter it or reset the FRP lock via EDL.

FAQ: Frequent questions about the Redmi Note firmware 4