[Huawei Mate 9 Guides, News, & Discussion] ante0:
I bricked my Mate 10 Pro while downgrading Pie to Oreo (Both 02 xloader).

Restored using testpoint and bootloader files in DC (v65+ has them iirc), then had to use IDT to flash unencrypted board as DC refuses due to security patch date.

Then I bricked xloader on purpose, as I had testpoint open already, and flashed fine without grounding testpoint to shield (As it's in testpoint mode when you have xloader brick).

It doesn't really flash XLOADER, it just allows you to use fbunlock fastboot which can flash anything. And that will allow you to use IDT to restore device.

Board has 01 xloader yes, but when board is installed it's still using 02 xloader so it's merely updating xloader rather than flashing it.

But it works fine.

The correct order to do things, requires DC Phoenix/HCU, unencrypted Board software and IDT (gem-flash has board and IDT)

Download board software, dload firmware, IDT, HCU and DC Phoenix, unzip all. Install drivers from DCs unbrick guide.

1. Flash Kirin960 Bootloader using DC Phoenix (It will only allow you to flash one of them so you need to test all kirin960 bootloaders). Device ends up in fastboot when you have flashed the correct one, and DC will tell you.

2. Flash Board software using IDT (you can flash everything directly from fastboot but I have not tested that method yet, and when you flash xloader from a 02 firmware you will not be able to use DC/IDT again without testpoint) (Note: you can remove oeminfo erase in xml to avoid it from being wiped. If you don't you will need a backup of it)

3. Boot to board software once.

4. Flash oeminfo (own backup) from fastboot, then reboot to system. Device will now factory reset and fail. Tap the chinese texted button. (You may edit board .xml to not erase oeminfo)

5. Backup modemnvm_system, modemnvm_factory and modemnvm_backup using dd in adb shell:

adb shell "dd if=/dev/block/bootdevice/by-name/modemnvm_system of=/sdcard/modemnvm_system.img"

adb shell "dd if=/dev/block/bootdevice/by-name/modemnvm_factory of=/sdcard/modemnvm_factory.img"

adb shell "dd if=/dev/block/bootdevice/by-name/modemnvm_backup of=/sdcard/modemnvm_backup.img"

6. Adb pull modem files:

adb pull /sdcard/modemnvm_system.img

adb pull /sdcard/modemnvm_factory.img

adb pull /sdcard/modemnvm_backup.img

7. Flash modemnvm_system and modemnvm_factory and modemnvm_backup from fastboot

fastboot flash modemnvm_system modemnvm_system.img

fastboot flash modemnvm_factory modemnvm_factory.img

fastboot flash modemnvm_backup modemnvm_backup.img

fastboot reboot

8. Modify and brand with HCU (check everything in the CDMA tab but those that erase/flash empty board) (remember to fill vendor and cust, hw and eu for example.)

Phone will now reboot

9. Unlock Sim with HCU

Phone will reboot

10. Read Bootloader code (This is important as your old code, even though it displays the exact same one, will not work without reading it first when you have a working phone. Not sure if Huaweis original code works though). DC seems to patch OEMINFO to get their code working (Search for DC-UNLOC in a oeminfo backup if you ever used HCU/DC to generate unlock code)

Phone will reboot

11. Use DLOAD firmware from androidhost.ru to flash in DLOAD mode. There's also a thread in this part of the forum with some dload firmware.