[Xiaomi Mi Max ROMs, Kernels, Recoveries, & Other D] nijel8:
All CM13 and RR releases we have so far are using pretty old China Dev MIUI v.6.6.30 as base not even listed on Xiaomi Downloads anymore. This as some of us know is the cause of all bugs we've had with these custom ROMs and were fixed by replacing vendor files from newer MIUI versions. On top of that some helium users cannot reboot to recovery from Android, phone doesn't power off... things like that... which most likely is due to using the wrong hydrogen kernel in this builds. Some users including me are experiencing no data going thru on good connection... Not gonna even mention VoLTE etc. So we still have bugs...

The vendor files and kernel that comes from MIUI as base are the main part that makes the hardware working flawlessly with the Android OS. These files are proprietary files with closed code, we can't change them so we have to rely on whatever Xiaomi do to optimize device performance. But we can choose which version to use and that is my goal here... Test and find the best set that works with custom ROMs.

Here we go... I have been testing the latest Global MIUI as base for two days now and so far haven't seen any issues at all. That doesn't mean no bugs... More time and testing is needed. But at least they are not any worst than what we are using now.

The common sense and logic is(fixed bugs proved that) vendor files and kernel from latest stable Global MIUI for the particular device should have more bug fixes and optimizations for the world out of China(I hope)... So using the best of my knowledge I compiled these two sets for:

HYDROGEN:

Based on latest Mi Max official Global MIUI v.8.0.1 (miui_MIMAXGlobal_V8.0.1.0.MBCMIDG_3657fef420_6.0.zip)

Download: vendor-base801MG_update-HYDROGEN.zip

HELIUM:

Based on latest Mi Max Prime official Global MIUI v.8.0.3 (miui_MIMAX652Global_V8.0.3.0.MBDMIDG_2da4c7e9db_6.0.zip)

Download: vendor-base803MG_update-HELIUM.zip

These packages are not recovery flashable zips!!! Keep reading for install instructions!

The install will get all vendor proprietary files I know of, firmware and kernel properly updated for the device code. Let's hope we get the better and latest from Xiaomi...

INSTALL INSTRUCTIONS:

MAKE TWRP BACKUP OF SYSTEM AND BOOT PARTITIONS BEFORE ANYTHING TO REVERS CHANGES IF YOU NEED TO!!!

The installation process is a little bit involving due to replacing the kernel in the actual installed boot.img in your device. I can't supply universal updated boot.img because they might be different from one release to another. I want to update what you already have. Did my best to make it user-friendly as I can without coding special app or something. Thanks to this guy whoever he is for the boot.img tools https://github.com/xiaolu/mkbootimg_tools.

Follow the steps and you should be fine:

1. Download the appropriate zip for your device code and unzip it to the root of your internal storage. You should end up with /sdcard/vendor_update folder;

2. Open your favorite terminal emulator app and execute the following commands one at a time pressing ENTER after each line:

su

hit ENTER

cp /sdcard/vendor_update/vendor-updater.sh /data/local/tmp/

hit ENTER

chmod 777 /data/local/tmp/vendor-updater.sh

hit ENTER

sh /data/local/tmp/vendor-updater.sh

hit ENTER

Alternatively you can USB connect your phone to computer and run the same commands from adb shell.

For HYDROGEN users:

That's all you have to do. The script will update your kernel and automatically will reboot phone to recovery and update vendor files so save your work before running the commands!

For HELIUM users:

Due to that can't reboot recovery bug you have to reboot manually by holding POWER and VOLUME+ buttons or fastboot method... The vendor zip will be flashed automatically and phone reboots back to system. If not, install /sdcard/vendor_update/vendor_update-HELIUM.zip manually and that's it.

Simple stuff if you decide to test these packages...

To verify update you should see kernel and baseband versions in About Phone changed like in the attached hydrogen screenshot. I can't test helium so they might be a little different. Check WiFi also... If you can turn it on and works all is good...

Helium users see if you can reboot to recovery from Advanced Power Menu, check if you can Power OFF your phone etc... the usual bugs.

Let see if these updates change anything for good or bad.

Happy testing!:good:

EDIT: Looks like 3G bug is still present in latest MIUI modem files. Flash CM_3G_fix.zip and keep the rest of the update if 3G bug is back.