[Xiaomi Mi Max 2  ROMs, Kernels, Recoveries, & Othe] lekhraj.gupta@gmail.com:
You should be having proper knowledge of flashing Custom ROM and how to Restore phone if anything goes wrong.

Take complete backup before taking any action based on this thread. I am not responsible for any action taken by you.

I am just compiling all the information/ files available on different English/ Chines websites into this thread, hence all Credit goes to respective developer/s. I am not a Developer and can't help you in making any further changes/ update to this ROM. I request XDA moderator and/ or Developer of Respective files to let me know if I have to mentioned (give credit) their name in this thread. The Download Links are given directly from respective Developer/s.

You need the following files to Teste MIUI Oreo on Mi Max 2 (Oxygen). These ROMs are ported from different Xiaomi Redmi/ Mi devices and Stable enough for daily use on Mi Max 2. I have MM2 4/64 Global version. You need ROM files from either S. No. 3 OR 4 as per your choice.

1. Treble Mi Max 2 Recovery 3.2.1 (https://androidfilehost.com/?fid=5862345805528056270)

2. LineageOS 15.1 Treble ROM for MM2 (https://androidfilehost.com/?fid=11410932744536984455)

3. MIUI Oreo ROM ported from Mi Max 3 China version and 5 Patch files (2 patches are Zipped in ROM zip) (https://onedrive.live.com/?authkey=!ADOiQOH2AEPHPvw&id=675E0DE17AFE7624!1416&cid=675E0DE17AFE7624) (No Gapps included and refer below section for installing Google Play Store)

4. MIUIpro Oreo Rom ported from Redmi Note 4x 8.11.15. This includes Gapps and no need to install Google Play store separately. (https://mega.nz/#!8LxgSK5B!MiUdWqnJltPi_zXdHPAYd_abZhL8LMPdej5FfIfzspQ)

Now don't waste time and start flashing MIUI Oreo rom into MM2.

First step

Start your phone into recovery and Flash the Treble recovery, if already not flashed. Restart into Recovery.

Click Wipe then Advance wipe and clear System, Vendor, Data, Cache, and Dalvick cache.

Above May have Mounted the System and Vendor after clearing.

Unmount the System and Vendor

Flash LOS-15.1 Rom as a normal zip ROM flashing process and DON'T reboot into system (this will make your phone treble enabled and update vendor automatically). No need to flash anything else.

Second step

Clear/ wipe System only

Mount the Vendor again

Enter the File management in Recovery and Delete following files:

/vendor/etc/permissions/qti_permissions.xml

/vendor/etc/permissions/qcrilhook.xml

/vendor/etc/permissions/telephonyservice.xml

/vendor/framework/qcrilhook.jar

/vendor/framework/QtiTelephonyServicelibrary.jar

/vendor/app/ has *.apk, delete /vendor/app/*.apk remaining (all apk in all sub-folder under /vendor/app/ folder)

Now Extract the Downloaded Rom files in Recovery backup folder. You should know where and how to Extract. (Use unzip in pc and copy paste to recovery backup folder.)

Click Restore and Select only System and Swipe to confirm. Wait for restore to complete. If any error, Mount the Vendor and try again Restore System process. After Restore completes DON'T Reboot.

Third step

Mount the Vendor and System again.

Flash Patch1 and Patch2

Mount the Vendor and System again.

Flash BrightnessFix, WifiFix and SoundFix

Clear only DATA and boot into System. Wait for upto 10 Minutes or more to boot into System.

Warning: When you Flash the patch files, please mount the System and Vendor first to avoid error 7.

What work:

Camera, Fingerprint, Face unlock, Wifi, Sound, VoLte (No ECHO issue), Auto Brightness, OnScreen HW buttons

What doesn't work:

Some people can't log in to Xiaomi account. Don't try to Flash Dolby sound.

The dual 4G is not working. There may be potential signal problems for some user but I didn't faced in Delhi with Airtel operator. Eye protection mode/ reading mode.

Since base MIUI Oreo rom is Chinese version no Gapps included. To get Play store DO'NOT flash Gapps. You need Google app to have Play store working. Search on Google for more info or try as per link (https://www.techadvisor.co.uk/how-to/mobile-phone/install-google-play-xiaomi-3676150/).

Guys, this is a nearly perfect MIUI Oreo package for our lovely Xiaomi Mi Max 2 (Oxygen), miui pie's camera can't be used in this ROM. Since Xiaomi does not released the updated Kernel source for our Device, user may not be able to change the In Call Volume.

If I missed anything in the above, kindly let me know to include. If you found any further update/ patch that makes this ROM more stable/ perfect or enables new feature, please don't hesitate to ping me to include in this thread.

I am not including any Screen Shot as all MIUI Roms looks same and there is No UI change based on Android Version in MIUI.

Best of Luck and Happy Flashing :)