[Huawei P20 Guides, News, & Discussion] RealDexxo:
READ NEXT POST!!! MORE INFO DOWN THERE.

First you need to downgrade to EMUI 9. You can do it by downgrading with HiSuite (Connect phone, setup hisuite, click update and then click "switch to other version").

After you have downgraded, you need unlocked bootloader. If you don't have that, pay 20€ for hcu client and you can unlock it but you need to disassemble your device.

It should look something like this.

View attachment 5643839

After you have unlocked your bootloader, you can install twrp.

1. Go to fastboot mode by turning your device off, holding volume down and connecting usb cable from your computer.

2. Once you are in the fastboot, you need to get a twrp. Huawei P20 only have unofficial twrp that is too old so we won't use that. We will use TWRP from P20 Pro.

3. Go to https://eu.dl.twrp.me/charlotte/ and download the latest file. Move it to adb folder.

4. Open ADB (https://developer.android.com/studio/releases/platform-tools) and type "fastboot devices". If you see your device there, it's fine. If you don't see it there, you need to get drivers. (I won't include them here, find it yourself on google.)

5. Type in "fastboot flash recovery_ramdisk twrp-3.6.2_9-0-charlotte.img". (If you have newer twrp version, change the file name.)

6. Type in "fastboot reboot". Now you have TWRP working!

Problems with TWRP:

Touchscreen is not working so you need to have mouse on OTG (USB-C to USB-A adapter).

Media transfer is also not working so you need to push the files with ADB.

"/sdcard" is encrypted after installing rom so you can't really use it, you will only see some random folder names.

Huawei P20 Limitations.

You can only flash roms up to android 11.

How to install custom rom.

1. Head over to this website: https://sourceforge.net/projects/amber-gsi/files/

2. Choose rom that you like. For example I'll use nusantara-11.

NOTE:

Always choose "arm64, ab"

View attachment 5643843

3. Download rom, extract it from the .xz (use 7-zip). Put the IMG in the ADB folder.

4. Enter the TWRP. (Power off, hold volume up and power button and when you will feel vibration release the power button.)

5. With mouse, confirm modification. Connect your phone to pc. Open adb command prompt.

6. Type "adb devices". If you see your device there, it's fine. If you don't see it there, you need to get drivers. (I won't include them here, find it yourself on google.)

7. Type "adb push <your-rom-name> /data" for example, "adb push Nusantara_v2.5.1-11-arm64-ab-Vanilla-GsiTestProjects.img /data".

8. On your phone, click install and navigate to /data. Click "install zip", it should change to "install image".

9. You should see your rom here. Click on it and flash it as system image.

10. Now you need to format your data! Go to main screen, click WIPE, format data. Type yes and continue.

11. Once it's done, you should have "done." as your last message but it will keep loading. Hard restart your phone (hold power button), wait until "your device has been unlocked" screen and hold volume up for 3 seconds. You should have Erecovery here. Click "wipe/factory reset data". Type yes and click format.

12. Phone should restart to TWRP. Click reboot and click power off. Now turn on your phone.

13. Wait until it boot. It can take some time.

You should have your ROM installed.

How to install GApps?

View attachment 5643847

1. Go to twrp, connect ur phone to pc.

2. Download gapps from here: https://opengapps.org/ (ARM64, android version depends on your rom, variant - nano or pico.)

3. Put the file in the adb, open up adb and type in "adb push <file_name> /tmp".

4. Go to /tmp in twrp, click on the file and install it.

Last notes:

If I missed something, just write in the replies.

Pushing rom to "/data" is due to "/tmp" having only 1.4gb space.

If you need to free up space, remove the rom file. (open up adb, type "adb shell", "cd data", "rm <file_name>".

"/tmp" always removes files after restarting device.