Xiaomi Mi 9 (cepheus) Firmware Flash File Download [Stock ROM]
The Mi 9 (codenamed cepheus) was Xiaomi’s flagship smartphone featuring a Snapdragon 855 processor, triple 48MP AI cameras, and 20W wireless charging. If your device is experiencing camera malfunctions, performance issues, battery drain, or software instability, this guide provides the official MIUI fastboot ROMs needed for complete system restoration.
Important Notice: Verify your device codename is cepheus before flashing. The Mi 9 has advanced camera capabilities and wireless charging that require specific firmware. Flashing incorrect firmware will result in a non-functional device.
Quick Device Specifications
- Device: Mi 9 (cepheus)
- Release Year: 2019
- Chipset: Qualcomm Snapdragon 855 (7nm)
- Display: 6.39″ AMOLED, 1080 × 2340 pixels (19.5:9)
- Camera: 48MP (Sony IMX586) + 12MP + 16MP triple rear, 20MP front
- Battery: 3300 mAh with 27W wired + 20W wireless charging
- Security: In-display fingerprint scanner
- Special Feature: 20W wireless charging, Game Turbo 2.0
- Original OS: Android 9.0 Pie, MIUI 10
Essential Downloads & Tools
| File / Tool | Download Link |
|---|---|
| Xiaomi Mi Flash Tool | Download Latest Version |
| Qualcomm USB Drivers | Download Latest Drivers |
| ADB and Fastboot Tools | Official from Google |
| Mi Unlock Tool | Bootloader Unlock |
Official Fastboot ROM Collection
| Region / Variant | Build Version | Android | Release Date | Download Link |
|---|---|---|---|---|
| China Stable | V12.5.6.0.RFACNXM | 11.0 | 2021-11-25 | Download |
| Global Stable | V12.5.1.0.RFAMIXM | 11.0 | 2021-06-11 | Download |
| Europe (EEA) | V12.5.2.0.RFAEUXM | 11.0 | 2021-11-12 | Download |
| Xiaomi.eu (Custom) | V12.5.6.0.RFACNXM (Based) | 11.0 | — | Download |
Flashing Guide for Mi 9 (cepheus)
- Driver Installation: Install Qualcomm USB drivers on your computer before connecting the device.
- Bootloader Unlock: If flashing different region ROM, unlock bootloader first using Mi Unlock Tool (requires Mi account authorization and waiting period).
- Enter Fastboot Mode: Power off device, then hold Volume Down + Power buttons until Fastboot logo appears.
- Flash Process:
- Extract the downloaded .tgz file to access the firmware folder
- Open Mi Flash Tool and browse to the extracted folder
- Select “Clean All” option for a fresh installation (recommended for troubleshooting)
- Click “Flash” and wait for the process to complete (typically 5-7 minutes)
- First Boot: Initial boot may take 5-10 minutes as the system optimizes applications.
- Sensor Calibration: After setup, calibrate the in-display fingerprint sensor and cameras through settings.
Frequently Asked Questions (FAQs)
Q1. Why is my 48MP Sony camera not working properly after update?
The Sony IMX586 sensor requires specific calibration. Flash the complete stock ROM and recalibrate the camera through the hardware test menu (##6484## → Camera Test). This often resolves focus and image processing issues.
Q2. Can I upgrade to Android 12 on Mi 9?
No, Android 11 was the final official Android version for Mi 9. However, there are custom ROMs like Pixel Experience and LineageOS 19 (Android 12) available if you unlock the bootloader and install custom recovery.
Q3. Why is my wireless charging not working after flashing?
The 20W wireless charging requires specific firmware calibration. Flash the stock ROM for your region and ensure you’re using an approved Xiaomi wireless charger for optimal performance.
Q4. Which ROM is best for battery life on Mi 9?
The Global V12.5.1.0 offers good battery optimization. The 3300mAh battery benefits from regular calibration and using battery optimization features in MIUI.
Device-Specific Troubleshooting
- Camera Performance: The triple camera system with 48MP main sensor requires specific calibration. Test all cameras after flashing.
- Wireless Charging: Ensure proper alignment with wireless charger and use original Xiaomi 20W wireless charger for best results.
- Battery Optimization: The 3300mAh battery may need calibration after flashing. Use full charge-discharge cycles for accurate percentage reading.
- Performance Management: The Snapdragon 855 is still powerful. Use Game Turbo for enhanced gaming performance and thermal management.
Version Comparison Advice
China ROM (V12.5.6.0): Newest features, latest security patches (November 2021), but may contain Chinese apps and lack some Google services optimization.
Global ROM (V12.5.1.0): Better Google services integration, stable for international users, but older security patches (June 2021).
EEA ROM (V12.5.2.0): European version with GDPR compliance, newer security than Global (November 2021), optimized for EU markets.
Xiaomi.eu ROM: Best compromise – based on China ROM but debloated, with Google services added, and optimized for global use.
Special Considerations for Flagship Device
Camera System: The 48MP+12MP+16MP triple camera setup requires optimal software calibration for best performance.
Wireless Charging: The 20W wireless charging is hardware-specific and requires proper firmware support.
Performance: The Snapdragon 855 remains capable but may benefit from thermal management optimization in newer ROM versions.
Display: The AMOLED display with in-display fingerprint reader requires specific calibration for optimal performance.
