Owners of Xiaomi, Redmi and POCO devices often encounter the acronym ARB when trying to install custom firmware or return the official version of MIUI. Anti-Rollback is a security mechanism implemented by the manufacturer to prevent the installation of older versions of the software. This is done to protect user data and prevent vulnerabilities that could be closed in new updates.
Ignoring ARB status can have fatal consequences for your smartphone. If you try to flash a device with a lower protection index than the one recorded in memory, the gadget can turn into a brick. That is why the question of how to check Xiaomi ARB before any manipulation of the software is critical for any modder.
In this article, we will break down all the available methods for diagnosing the level of protection, explain the difference between the global and Chinese versions, and provide tools for safe work with the bootloader.
What is the Anti-Rollback Mechanism and How It Works
The Anti-Rollback mechanism is a special counter that is stored in a secure area of the processor memory. Every time you upgrade to a new official version of MIUI or HyperOS, this counter can increase. Its value is never reduced by software methods.
When you try to install a firmware, the system compares the ARB index in the file you install with the index recorded on the device. If the firmware index is less than the current device index, the installation process is blocked at the bootloader level. In the worst case, especially on Qualcomm processors, this leads to a lock on the system boot.
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Always check the ARB version of the firmware you plan to install. It should be equal to or higher than the current version of your device.
It's important to understand that not all updates increase this index, which is usually only when major Android updates or critical security patches are released, but you can't rely on luck, you have to check.
Checking ARB status through the Engineering Menu
The fastest way to know the current security status is to use the hidden engineering menu available on most Qualcomm-powered devices, a method that doesn’t require a computer connection and works directly on a smartphone that’s turned on.
To enter the menu, you have to open the standard "bell ringer" and enter a special code, and the screen will display an interface with many technical parameters, and we are interested in the tab responsible for version and protection.
- 📱 Enter the code ##6484## or #4636## in the phone app.
- 🔍 Find the item "Version information" or "Version information».
- 📉 Look for the line “Anti-rollback status” or «AR Status».
- 🔢 The number next to this item is your current level of protection.
If the menu displays a value of "0" or "1", this means a minimum level of protection, and you are likely to be free to experiment with firmware. values of "3", "4" and higher require extreme caution. On some models, such as the Redmi Note 8 Pro, this method may not show the exact number, then it is worth resorting to other methods.
Diagnostics via Fastboot and ADB mode
A more reliable method that works even if the smartphone system is damaged is to check through Fastboot mode, USB-cable and installed drivers ADB/Fastboot. This method provides the most accurate information directly from the bootloader.
Put your smartphone into Fastboot mode by clamping down and power buttons at the same time. Connect the device to your PC. Open the command line or terminal in the ADB tool folder and enter a command to get device information.
fastboot getvar allYou'll get a long list of variables, and you'll need to find a string that contains the word "anti" or "rollback." For example, (anti) 3. This number indicates the current protection threshold. If there's no such string, maybe your model has implemented the mechanism differently or disabled.
⚠️ Note: Entering commands in Fastboot mode requires care. An error in the syntax of the fastboot command can lead to unpredictable behavior of the device, although the getvar command is secure and only reads the data.
You can also use the fastboot getvar anti command, which will immediately give the desired value if the variable is supported by a particular device. On MediaTek processors, this method may differ and require the SP Flash Tool utility to be used in read mode.
Analysis of firmware files before installation
Before you start firmware, you need to check the firmware file itself. Archives with official and custom firmware often contain information about the required anti-rollback level, which is especially true for global versions of MIUI, where protection was implemented in stages.
To analyze, you’ll need to unpack the firmware archive (usually a zip file) and find the payload.bin file or text manifests. However, there’s an easier way to do that is to look at the documentation for a particular firmware in the developer forum (4PDA, XDA), which always lists the required ARB status.
☑️ Firmware check
If you use tools like the Mi Flash Tool, pay attention to warnings. The program can automatically detect version mismatches and block the process, but you shouldn't rely on it. Manual rechecking through the payload.xml reading (if it's unpacked) gives you a 100% guarantee.
Table of compatibility and levels of protection
Different models and regions have different security policies, and here's a table showing the typical values for popular product series, and remember that this data may change as new security updates come out.
| Model of the device | Region | Max. A famous ARB. | Risk on rollback |
|---|---|---|---|
| Redmi Note 8 Pro | Global / RU | 3 | The Critical (Hard Brick) |
| Xiaomi Mi 9T Pro | Global | 4 | High-pitched |
| POCO F1 | India / Global | 1 | Medium (Bootloop) |
| Xiaomi 13 | China | 2 | High-pitched |
As you can see from the table, even the same model in different regions can have different protection thresholds. Chinese versions are often updated more aggressively, but global versions can have stricter restrictions on unlocking the bootloader after an ARB boost.
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Never stitch Chinese firmware onto a global device (and vice versa) without knowing the current level of ARB, as the thresholds may not match.
Consequences of neglecting protection and recovery
What happens if you do install a low ARB firmware? On Qualcomm-powered devices, the scenario is often the same: the phone turns off and no longer responds to buttons. The screen remains black, the computer makes the device connect in EDL (Emergency Download Mode) mode.
It is no longer possible to restore such a device using software methods (via Fastboot), since the bootloader is locked at the hardware level, the only way out is to use an authorized Mi Account account to run through EDL mode (you need to contact the service) or programmable soldering of the memory chip, which is expensive and difficult.
⚠️ Note: If your smartphone is gone EDL mode (lights are on, but the screen is black and vibrates), do not try to “revive” it by charging or pressing the buttons long.
On some models with MediaTek processors (such as the old Redmi), only a bootloop can cause a rollback, in which case it sometimes helps to enter Recovery mode and reset settings, but there are no guarantees.