[Samsung Galaxy Note 9 (Exynos) ROMs, Kernels, Reco] Montero7o:
Good morning all,

The objective of this method is to have an Android 10, with Root with TWRP operational for backups and restoration of all partitions.

I spent many days (nights) researching XDA to develop this procedure and find out how Android Q blocked the mounting of partitions from the start after the installation of the ROM.

I tested on my 2 Galaxy Note 9 SM-N960F

REQUIREMENTS:

Have a Note 9 SM-N960F

Andoid Q stock ROM: N960FXXS4DTA1-XEF (or the next ROMs)

Odin3 v3.14.1

TWRP for Android 10: twrp-3.3.1-r3.7-Q-crownlte.tar

Magisk: magisk-canary - Copy to ExtSDCard

Dm-Verity & ForceEncrypt Disabler v02.02.2020 - Copy to ExtSDCard

Have a "BootLoader" already unlocked.

Very important the order of pressing the keys: If it is noted "Power" + "Bixby" + "High Volume", do not do "Bixby + Power + High Volume", respect the order of the keys.

STEP 1: On your Andoid PIE or Q, Activate the developer mode

-Activated = ON

-OEM unlocking = ON

-Auto system update = OFF

- USB debugging = ON

-Check apps via USB = OFF

-Verif bytecode debuggable apps = OFF (only available on Android 10)

- Default USB connection = File transfer / Android Auto (Android Auto is only present in Android 10)

Turn off Note 9, "Power" button

STEP 2: Flash the stock ROM

1-Restart in Download mode

-Hold the Note 9 in the palm of one hand and with the thumb press the "Bixby" button and keep it pressed,

-With the other hand, plug the USB cable into the phone,

-Then press the "Volume Down" button with your free hand.

-As soon as the first screen is displayed, release the buttons, then confirm with the "High Volume" button

Now open Odin on your PC in Admin mode,

-Important: check "Auto Reboot" and "F.Reset Time" in the Odin options and nothing else.

-Select your AP, BL, CP and CSC_xxxx firmware files (do not put HOME_CSC), then click on "Start"

You got the "PASS!" in Odin, the Note 9 will restart and you will see a blue screen indicating that your device is updating for 2 to 5 seconds, then the Note 9 will restart again.

Very important: As soon as the screen turns off for a second restart, you must press "Power" + "Bixby" + "Volume High" to force the boot on the Recovery stock.

This is very important because if it starts initializing, mounting partitions in TWRP will be impossible and you can start again from point 1.

-Use the volume buttons to navigate the Recovery stock menu and the power button to select an option.

- Choose the "Power Off" option and remove your USB Type-C cable from the Note 9.

STEP 3: Flash TWRP

1-Restart in Download mode

-Hold the Note 9 in the palm of one hand and with the thumb press the "Bixby" button and keep it pressed,

-With the other hand, connect the usb cable to the Note 9,

-Press the "Volume Down" button with your free hand.

-As soon as the first screen is displayed, release the buttons, then confirm with the "High Volume" button

2-Now open Odin on your PC in Admin mode,

-Important: Uncheck "Auto Reboot" and leave checked "F.Reset Time" in the Odin options and nothing else.

-Select in TW the file TWRP (twrp-3.3.1-r3.7-Q-crownlte.tar) then click on "Start"

-You got the "PASS!" in Odin, remove the USB Type-C cable from the Note 9.

3-The next step is very important, you must force the Note 9 to stop, then restart in Recovery mode

Press "Power" + "Volume Down" for 7 seconds to exit the download mode.

As soon as the screen turns off, immediately press the "Power" + "Bixby" + "Volume Up" keys to start Recovery, as soon as the screen turns on release all the buttons.

After a first boot, if the screen turns off and then restarts, immediately press the "Power" + "Bixby" + "Volume High" keys,

You must have the TWRP screen, if this is not the case, initialization has started, you must repeat all the procedure in point 1 because the TWRP fash will not be operational for the rest.

STEP 4: Root of Note 9

-In TWRP, you must swipe to authorize the modification

-Now format your data, Press "Wipe", then "Format Data", then on the confirmation screen type "yes" to continue.

(Very important, If there are red lines during the format, there is a decryption error, then go back and reboot Recovery

Format your data again, Press "Wipe", then "Format Data", then on the confirmation screen type "yes" to continue.)

- Back button for the first screen, then press "reboot" then "Recovery"

-Now you need to Install Magisk Canary in TWRP,

-Click on "Install" and select "Magisk Canary.zip" located on the ExtSDCard then validate the flash.

-You must have the message "Done"

-Return back, then Install then "Dm-Verity & ForceEncrypt Disabler v02.02.2020" located also on the ExtSDCard.

-You must have a message "Done", then an error line "Failed to mont '/ odm" then done, ignore it.

Click "Reboot sytem" to start your system.

Configure all the settings, install your applications and test the full functionality

Important: If you are switching from Android PIE to Android Q, it is preferable not to authorize the restoration from Google or Samsung, but to redo the installation of the applications from the Google Store or from your APKs.

STEP 5: Backing up the partitions

-Turn off Note 9 with the "Power" beam

-Press the keys "Power" + "Bixby" + "Volume High" to start in TWRP

-You should no longer have the "swipe to authorize the modification" screen, if this is the case then authorize the modification again

-Select "Backup", then activate all partitions.

-Select ExtSDCard or OTG as destination

-Set "Today's date + INIT-Android 10" as the backup name, then zip to start the backup.

(Very important, there must be no error otherwise the partition (s) are locked by Android 10 and restoration will be impossible)

-If the backup is OK, click the restart button.

STEP 6: Test the Restoration of the partitions

-Turn off Note 9 with the "Power" beam

-Press the keys "Power" + "Bixby" + "Volume High" to start in TWRP

-Click on "Restoration"

-Select the previous backup then zip to start the Restoration.

(Very important, there must be no error otherwise the partition (s) are locked by Android 10 and recovery is impossible, TWRP is badly initialized and locked by Android)

-If the Restore is OK, click the restart button.

It's over.

Thanks to Zackptg5, topjohnwu and jcadduono for the "Dm-Verity & ForceEncrypt Disabler v02.02.2020"

Thanks to Geiti94 for the twrp-3.3.1-r3.7-Q-crownlte.

Good reading