You want to update the firmware, as it does not suit you in terms of functionality.
Where can I find the firmware?
On the official website of your phone manufacturer.
On sites where third-party developers post custom operating systems.
What should be done before installing the firmware?
Back up your contacts and user data and transfer it to your computer.
Insert an SD card into your phone to write the firmware to it.
Determine your smartphone model.
Fully charge your device. If the battery runs out during the firmware, the device will no longer turn on.
Download archive with Firmware. Place it on the SD card.
Installing TWRP Recovery
Download the Official TWRP App to your phone from the Play Market. And install this app.
When you start the application for the first time, you must consent to future manipulations, as well as consent to granting the application Superuser rights. Check the checkboxes and press the 'OK' button.
After moving to the next screen, you need to select the 'TWRP FLASH' item and give the application root rights.
On the main screen of the application, click 'Select Device', and find your phone model.
After selecting a device, the application will direct the user to a web page to download the appropriate modified recovery environment image file. Download the suggested *.img file.
When the download is finished, you need to return to the main screen of the Official TWRP App and click on the 'Select a file to flash' button. Select the file downloaded in the previous step.
Press the 'FLASH TO RECOVERY' button and confirm your choice, press 'OK'.
After the burn process is complete, the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure can be considered complete..
Transfer the necessary files to the SD memory card. Using a PC or laptop card reader, it will be much faster.
Insert a SD memory card into the phone.
To reboot into recovery, you need to enter the menu accessible by pressing the button with three stripes in the upper left corner of the main screen of the application. Select the 'Reboot' item, and then click on the 'REBOOT RECOVERY' button. The phone will reboot into the recovery environment automatically..
Firmware via TWRP
Before flashing, you need to clear the 'Cache' and 'Data' sections, press 'WIPE' on the main screen. You will delete all user data from the phone, this will avoid software errors and other problems.
You can start flashing. Click the 'Install' button.
On the file selection screen, at the very top there is a 'Storage' button for selecting an SD card.
Select the storage to which the files were copied.
Find the file we need and click on it. A screen opens with a warning about possible negative consequences, you need to check the item 'Zip signature verification', which will avoid using corrupted files when writing to the phone's memory sections.
The procedure for writing files to the phone's memory will begin, this is accompanied by the appearance of inscriptions in the log field and the movement of the progress bar.
When the procedure for installing the firmware is completed, the message 'Successful' appears on the screen.
Summary: OS: Android v9.0 (Pie); Chipset: Qualcomm Snapdragon 855; CPU: Octa core (2.84 GHz, Single core, Kryo 485 2.42 GHz, Tri core, Kryo 485 1.8 GHz, Quad core, Kryo 485); Architecture: 64 bit; Custom ui: Android One; RAM: 8 GB; GPU: Adreno 640; Screen Size: 5.99 inches; Screen Resolution: 1440 x 2560 pixels; Screen type: P-OLED; Pixel density: 490 ppi; Bezelless display: Yes; Touch screen: Yes Capacitive Touchscreen, Multi-touch; Internal memory: 128 GB; Expandable memory: Yes Up to 400 GB; Front camera: 25 MP; Main camera: 13 MP 13 MP 13 MP 13 MP; Main camera: Yes 13 MP, Auto focus; Resolution: 25 MP Primary Camera; Camera setup: Single; Flash: Yes LED Flash; Image resolution: 4128 x 3096 Pixel ...
Comments, questions and answers on the flash firmware Nokia 9.1 PureView