[BlackBerry KEYone Guides, News, & Discussion] knreddy:
Warning: Don't install an older OS on top of a newer one, you may have a very high chance of bricking your phone. If you are ready to take risk of bricking for the sake downgrading / requirement or already bricked, then only attempt the following . you need an autoloader & build version exactly matching to your phone.

I have downgraded successfully from Build ABP244 (Android 8.1.0) to AAX862 ( Android 7.1.1)

Caution: Blackberry/Google may introduce any constraints against downgrade through future OTA updates to strengthen the security etc.

My Phone Details:

BlackBerry, Keyone, Special Edition, Dual Sim, India.

PRD: PRD-63764-001 (Group: KEYone BBB100-7)

OS Build: ABP244 (Android 8.1.0)

[Upgrade history from ABB216 (android 7.1.1) to ABG076 (Android 8.1.0 ) ….to…to ABP244(Android 8.1.0 )]

1.	I have checked phone PRD, by typing the following code into the phone dialer:

*#2886#

Clicked on "MANU"

Clicked on "Traceability"

There you can see phone's manufacturer no: Mine is PRD-63764-007 (for example) (photo#1 in attachment)

Exited from the menu click "PASS"

Then again clicked "PASS"

At the end of the menu clicked "exit"

2.	compared with PRDs master at https://tclota.birth-online.de/ and download suitable Autoloader (ROM and its flasher)

3.	AAX862 (it is written as AAX863 but actually AAX862) which is suitable to above PRD No is downloaded from

https://androidfilehost.com/?fid=890129502657599708

Topic: https://forums.crackberry.com/blackberry-keyone-f445/blackberry-keyone-autoloaders-1108372/

4.	Removed passwords /patterns / finger prints from screen lock (settings>security>screen lock>select none), Removed google account [ settings>Users & Accounts (or Accounts in case of android 7.1.1 ) >googel>options>Remove, remove google]

[removed find my device at device administrator , find from Google Account (settings> google> google account >options (3 horizontal line at rhs bottom)>manage devices>black berry keyone>remove>remove- i have done but this may not be needed]

Theory: On BlackBerry devices powered by Android, Factory Reset Protection (FRP) is enabled by default to reduce the value of a stolen device. This feature prevents the use of a BlackBerry device powered by Android unless authorized by the known user.

Once you sign in with a Google account, FRP is enabled. Once enabled, only users who have reset their device via Settings > Backup & reset > Factory data reset may proceed through the setup wizard without being prompted to enter the Google login information that was previously used on the device before resetting. This form of reset is the only reset flow that is considered trusted.)

[I have reset the device from Android (I have done, but this may not be needed]

[Enabled Developer options and usb debugging was made on (I have done, but this may not be needed)]

5.	Rebooted to fastboot mode by switching off >pressed and held volume down button and simultaneously , pressed power button till the phone restarts , then released volume down, once fastboot loads

[>select fastboot by pressing volume button , I have done, but this may not be needed (no further power button press)]

(photo#2 in attachment)

6.	Installed BlackBerry-USBDrivers-5.0.0.2 downloaded from the link below for windows and restarted the windows.

Downloaded from https://swdownloads.blackberry.com/Downloads/entry.do?code=4EE0932F46276313B51570F46266A608

7.	Connected it to Windows PC through USB port (Windows device manager photo#3 in attachment)

8.	Extracted AAX862Universal.7z with 7z

9.	Browsed to the above extracted folder, double clicked on file flashall.bat to run batch file (other option available is flashallnowipe.bat ).

10.	Entered y in response to question …….. to continue (y/n), (photo#4 in attachment)

it immediately rebooted to fastboot again (photo#5 in attachment) but the process was going smooth.

Process successfully completed (photo#6 in attachment) and phone is rebooted to OS in Auto

Sometimes, the phone can get stuck when booting for the first time. If this happens to you, make sure you've waited long enough, and then just hold the power button down to force a reboot.

It needs simcard or internet to reach user interface.

Caution:

When Autoloader build no AAY819 (common/universal to many PRDs but not all) downloaded from https://mega.nz/#!wVxBxYZA!BahovAZA_...M5Ic_QkJigS3LI and flashed, flashing is successful but when is updated from App Drawer >updates…22 mb downloaded , install started , rebooted and installed to 100% but message appeared that “ This is embarrassing, the update failed, try to install again later, your phone will reboot after 120 sec…. Error code 3305” , It reboots and build no shows as ABB216 but 2nd Sim is not working.

Reflashed with Build No AAX862, both sims and other hardware are working normal , Further when update option is used it is getting updated to ABB216 without any error again both sims and other hardware are working normal .

Stop updates

(this facility not available in Oreo)

Pre requisite : disconnect phone from Internet (Put off Wifi and mobile data)

1). App drawer>Updates>Options(3 vertical dots)>settings>system> check for updates –Off (=never), Automatically download – off (=ask to download)

2).	App drawer>Updates>Options(3 vertical dots)>settings>System applications > Automatically update –off (=never), new app notifications –off

If system update already started or pre -requisite is forgot: Go to Settings>Apps>Updates>Storage>clear data , now repeat step 1 & 2

Advantages:

1) The feel, the look , the smoothness , the speed , low in bugs of the build ABB216. It is excellent

2)	“True phone dialer & contacts” app has all most all the features, you ask it has already has, like blue mark for outgoing calls, green for incoming, saffron for canceled, red for missed call as history (it cannot work properly with Oreo latest due to restriction on call log, restrictions increased in ascending order from Build ABG076 to ABJ879 to ABM376 to ABP244 ). Never hangs while calling (OS).It has contact share through SMS with pleasant interface, excellent dual sim management etc.

3)	SMS Organizer by Microsoft also appears to be facing restrictions with Android 8.1.1 , hence it will be working excellently.

4)	Rear camera (of Build ABB216)a lot nearer to true to actual ( than Oreo Build ABG076)

5) Light Manager works flawless with very low power consumption for customization of notification LED as keyone has no built in facility to customize.

Disadvantages:

1) less secured than Oreo,

2) 7.1.1 Camera not far better than improved camera by build ABP244.

3) Oreo has configurable alarms but same is achieved in Nougat with updating of Time App

4) Oreo has PIP useful e.g. for maps

5) Google playstore installs regular patches without our control making older android slow

6) call history symbols are rarely used and minor , further they can be seen at stock phone (the issue still exist with Oreo compatible TruePhone v1.78) advantage 2 may be considered almost nullified

7) file Explorer scrolling goes back if some shaking taking place.

8) Download is interrupted few times from playstore even when Download from mobile data

9) usb data transfer is slow

10) all features of Silence premium do not disturb app are not working ( my favourite profiles app ) like whitelist and repeat calls will enable ring, interruptions to silence mode (app is defective up to v 2.15f ) but they have created v2.17 which works as designed but does not install on nougat.

11) Light flow can be installed in place of Light Manager on Oreo , hence advantage 5 nullified

However I am happy with downgrade and will maintain as long as possible or till I get apps to get the nougat like flexibility and user experience as per above mentioned facts at advantages.

Thanks to the respective contributors& community. This is only experience sharing , no credit or responsibility.

As the time progressed, disadvantages increased and advantages reduced . I have re-upgraded please on 22.12.19 especially due to functional requirement of Silence Premium as mentioned above and no equivalent is available.