How to Install Custom ROM on Redmi Note 12 and 12 Pro [GSI build]

In this tutorial, we will guide you to install the custom ROM on Redmi Note 12 and 12 Pro (ruby). Both devices have a 6.7-inch display, Triple Camera, and 5000 mAh battery. Redmi Note 12 and 12 Pro runs out of the box with Android 12.

If you are here, you may probably want to install the Custom ROM on Redmi Note 12 and 12 Pro. As you read our title, yes we can guide you on installing the latest custom ROM on Redmi Note 12 and 12 Pro based on GSI build.

When purchasing a new phone, it typically includes a pre-installed operating system known as a stock ROM or firmware. This stock ROM is limited in its functionality as it is defined by the phone manufacturer. However, a custom ROM is created using the Android Open Source Project (AOSP), which allows developers to edit or recompile the code according to their specific needs. For more information on the differences between custom ROM and stock ROM, please refer to our comprehensive article.

Flashing the ROM in Redmi Note 12 and 12 Pro is easy! All you need to do is follow the instructions carefully. If you are a newbie, then you need to understand that before flashing, you must unlock the bootloader on your Redmi Note 12 and 12 Pro. To unlock the bootloader, follow our guide on how to unlock the bootloader on any Xiaomi device.

If you have unlocked the bootloader, follow our guide to install the custom ROM on Redmi Note 12 and 12 Pro. Before that, let’s understand What is a GSI build.

What does GSI Stand for?

GSI stands for Generic system image, an Android System image that can be used to replace the current installed Android version with a new one. It is a pure Android with an unmodified Android Open Source Project (AOSP) code. With Android 8.1, Google introduced the project treble support for many devices and now with Android 9.0 Pie, Google finally added the API level 28 to support Generic System Images to all app developers to install and run the latest Android GSIs on a variety of existing Android devices. To know more, Read here

How to Install Custom ROM on Redmi Note 12 and 12 Pro

To install, as we said, you need to unlock the bootloader and must have a TWRP (to install via a  device) or a PC (to install via Fastboot). Yes, two methods exist to install the custom ROM GSI on Redmi Note 12 and 12 Pro.

Pre-Requirements:

• This guide is for Redmi Note 12 and 12 Pro (ruby).
• You will be required to unlock the device bootloader at first
• ARM, ARM64, or x86: Check your Android Phone’s Processor
• Treble Support: Check If Your Smartphone Supports Project Treble
• Download the required file and Support the GApps file from below.
• Keep your device battery charged up to 60% at least for a smoother process.
• Take a complete backup of your device data without Root. In case anything goes wrong, you can easily restore all the data.
• Download and install Xiaomi USB Drivers
• For the adb method: Download ADB and Fastboot tool
• For TWRP Method: Download and Install TWRP Recovery on Redmi Note 12 and 12 Pro

Download Links:

• Download AOSP Android 12 GSI
• Download AOSP Android 13 GSI
• Download Project Elixir GSI
• LineageOS 19 Download – If a broken link, check the official forum

Install via TWRP Recovery:

This guide is for those users who have installed TWRP recovery on their devices. If your device is not supported, you can try the next method to install the custom ROM via GSI build.

1. To install via TWRP, you need to factory reset your device using TWRP
2. Go into the Wipe option and Swipe to Factory Reset.
3. Transfer the GSI build to your Redmi Note 12 and 12 Pro using a USB Cable.
4. Once you have moved, you can remove your USB cable.
5. In your TWRP, tap on the install button –> Change type to Install Image and find the GSI you have moved in the 3rd step.
6. Confirm the flash by choosing the system partition
7. Once it is done, you can reboot your device and wait for a few minutes to boot up.

Flash via Fastboot

1. 1. First, do the factory reset on Redmi Note 12 and 12 Pro (ruby). There are two methods to do it, follow anyone.
      • Factory Reset When Powered On: To install without TWRP, you have to factory reset using your Umdigi A7 Pro factory reset option.
      • Factory Reset via Stock Recovery: Reboot your Redmi Note 12 and 12 Pro into stock recovery using a button combination or ADB command.

        adb reboot recovery

      • In your Stock Recovery, navigate using the Volume UP and DOWN button.
   2. Make sure to extract the downloaded GSI build.
   3. After resetting the factory ROM, you can now boot your device into bootloader mode using the adb command adb reboot bootloader.
   4. Now open the extracted folder of the GSI build; there, now open the command prompt window by holding the SHIFT KEY and Right Mouse click.
   5. In your command window, enter the command fastboot erase system

1. 1. To flash the system image, enter a command in the following format: fastboot -u flash system name_of_system.img

1. Wait for the image to flash; it could take a few minutes. Once it has been completed, reboot your device either manually via the power key or by entering fastboot reboot and waiting for a few minutes to boot up.

We hope that this guide is helpful to you and you have successfully installed the Custom ROM on your Redmi Note 12 and 12 Pro (ruby) handset easily. If anything goes wrong or you have any queries, feel free to ask in the comments below.

Credits to all the developers from the XDA forum and 4PDA forum