How to Install Custom ROM

Introduction

This page will guide you to install custom ROM properly. I will try to make this guide easy to understand as possible, so you can install custom ROM with ease.

Pre-requisities

• Unlocked phone bootloader.
  

This is important, because without it you can't perform fastboot flash.

• Phone data cable
• Google USB Driver (Windows only, macOS/Linux already have the driver)
• Stock MIUI Fastboot ROM

NOTE: This depends on what custom ROM's Android version are you installing.
If you are installing Android 12 ROM, you should grab the latest MIUI with Android 12 ROM.

• Android platform-tools (adb and fastboot)
  • Windows: https://dl.google.com/android/repository/platform-tools-latest-windows.zip
  • macOS: https://dl.google.com/android/repository/platform-tools-latest-darwin.zip
  • Linux:
    • Arch-based distribution: sudo pacman -Sy android-tools
    • Ubuntu-based distribution: sudo apt install android-sdk-platform-tools
    • Fedora/openSUSE-based distribution: sudo dnf install android-tools
• Custom recovery
• Your favorite custom ROM file (can be downloaded here)
• A SD Card, to make things easy.
• Know some command prompt stuff.

Steps

Unpacking things

1. Unpack your MIUI ROM to somewhere accessible, like in C:\
2. Unpack the platform-tools content to C:\Windows\, just so that you can easily access them on cmd.
3. Move your ROM files to SD card, so you don't have to move the files after flashing.

Clean flashing

Warning

Be sure you have backed up your data to somewhere else before proceeding.
This entire process will erase your phone data and void your phone's warranty, so proceed with caution.

1. Shut down your phone
2. Boot into fastboot mode by holding down Vol Down + Power
3. Plug in your phone to your PC, wait for a moment for your PC to recognize your phone
4. Run command prompt, and check your device by running fastboot devices
   
5. If it's recognized, you can clean flash your phone by running flash_all.bat in the ROM directory.
6. While you wait, you can sit back and relax, grab some coffee and touch some grass for a while. Because clean flashing can take some time, depending on your PC hardware.
7. After it finished flashing, it should automatically reboot and let it perform its first boot.
8. Congrats, your phone is just like new!

Going to TWRP

Important

Make sure your custom recovery file is somewhere on your PC.

1. Shut off your phone.
2. While your phone is off, enter fastboot mode (Vol Down + Power).
3. Check if your phone is recognized on your PC by running fastboot devices on cmd.
4. Boot into TWRP by typing fastboot boot , and then drag your TWRP file to your cmd window.
5. Press enter, and you'll be greeted by the TWRP splash screen.

Installing Custom ROM

1. In TWRP, go to Wipe -> Format Data, then type yes. This is done to remove Android encryption on Internal storage.
2. After that, reboot to Bootloader this time, since we don't have TWRP installed yet.
3. Boot TWRP again using the previous steps.
4. Now go to Install, then select your ROM zip file that you moved to SD card.
5. Swipe to perform ROM flashing, and wait for a while. Flashing custom ROM usually take 5 minutes to complete.

Important

If you see these errors below, this is normal. This also means you have successfully installed the ROM. TWRP returned these errors because this phone has dynamic partition, therefore TWRP unable to mount it properly after a ROM install.

Additional touches

Note

If you don't want to install TWRP or any flashable ZIP files (like Magisk, GApps, or custom kernel), feel free to skip these steps and reboot to system immediately.

Installing TWRP

1. Go back to main screen
2. Go to Advanced -> Flash Current TWRP
3. Swipe to flash TWRP. It shouldn't take a while.
4. Reboot to recovery if you want to install flashable ZIP files, otherwise reboot to system.

Important

If you see the same error like after you flashed the ROM, you can safely ignore those, as those partition are not mounted properly after a ROM install.

Installing ZIPs

1. Go to Install
2. Select your flashable ZIP on the file manager.
3. If you need to install more ZIPs, you can Add more ZIP and select another flashable ZIP file you want to install.
4. Swipe to confirm flash.
5. Wait for a while.
6. You can reboot to system if the installation is completed without any errors.

End

That wraps up on "How to Install Custom ROM" tutorial. If you made it here, then congratulations! You've just installed your first custom ROM on your phone. Please do keep in mind that not every ROM is perfect in any way, and if you want to switch between ROMs for any reasons, nobody's going to stop you. It's your phone anyway, you can do whatever you want.