updates - How to Upgrade Sony Xperia Z3 Compact (D5803) to Android 8.1?

How do you upgrade the Sony Xperia Z3 Compact (D5803) to Android 8.1?

There are a number of web pages that attempt to answer this question, but none of them provide every step along the way. These include:

They all skip steps or are missing key pieces of information that someone who is unfamiliar with the process would prevent from completing. A comprehensive, step-by-step guide for a complete novice would be helpful.

Answer

These instructions describe how to upgrade the Sony Xperia Z3 Compact (D5803) smart phone. These instructions do not include backup instructions, so be sure to save any important information and then proceed at your own risk.

Requirements

• Laptop or Desktop - Windows 7


• Xperia - Stock Build Number 23.5.A.1.291 (revert if necessary)


• Xperia - Fully charged (100% recommended)



• Xperia Companion


• TWRP

Disclaimer

These instructions could brick your phone, rendering it a paperweight. Read all the instructions thoroughly at least once before you begin.

Unlocking the bootloader erases Sony's DRM-protected functionality, such as X-Reality Engine and Miracast. Unless you make a backup of a specific partition, the functionality will be permanently lost.

Enable Developer Mode

Enable developer mode on the phone as follows:

1. Power on the phone



2. Open Settings


3. Tap About phone


4. Scroll down to Build number


5. Tap Build number at least 7 times in succession


6. Enable developer mode

Developer mode is enabled.

Install Device Drivers

On the laptop or desktop computer, perform the following steps:

1. Disconnect Phone from USB, if not already disconnected


2. Download Flashtool v0.9.24.4 for Windows
   
   


3. Install into C:\Flashtool


4. Plug phone into laptop or desktop USB port


5. Run C:\Flashtool\drivers\Flashtool-drivers.exe


6. Check Flashboot Drivers


7. Scroll down


8. Check Xperia Z3 Compact Device Driver



9. Click Install


10. Accept any warnings that appear

The device drivers are installed.

Install Platform Tools

Download and install the Android Debug Bridge (ADB) as follows:

1. Download ADB platform tools


2. Unzip into C:\Program Files\platform-tools


3. Open a command prompt



4. Type: cd C:\Program Files\platform-tools


5. Type: adb devices


6. Authorize the connection on the phone.

The phone is listed and the ADB platform tools are installed.

Unblock the Bootloader

Advanced users can use Flashtool to unlock the bootloader, which is not described herein.

Unblock the phone's bootloader as follows:

1. Follow along with Sony's Guide



2. Complete Step 1: Check if the bootloader can be unlocked on your device


3. Skip Step 2: installing devices drivers and platform tools


4. Unplug the USB cable


5. Complete Step 3: Connect to Fastboot


6. Complete Step 4: Enter unlock key


7. Type: fastboot -i 0x0fce oem unlock 0x{UNLOCK CODE}
   
   
   
   • Replace {UNLOCK CODE} with the unlock code from Sony
   
   
   
   

The console shows:

...
OKAY [  1.544s]
finished. total time: 1.560s

The bootloader is unlocked.

Reboot

After the bootloader is unlocked, reboot the phone as follows:

1. Type: fastboot reboot


2. Wait for the reboot cycle to complete

The phone is rebooted with an unlocked bootloader.

TWRP

TWRP is a tool for writing custom software on mobile phones. Install TWRP as follows:

1. On the phone, visit https://twrp.me/sony/sonyxperiaz3compact.html


2. Install the Official TWRP App from the Play Store.


3. Download image into C:\Program Files\platform-tools:
   
   
   


4. Power off phone


5. Unplug USB cable


6. Press and hold volume down


7. Plug in USB cable


8. Wait for blue indicator light in top left (may have to re-plug in)


9. Type: fastboot flash FOTAKernel twrp_z3c_O_2018-05-09.img

The output resembles:

target didn't report max-download-size
sending 'FOTAKernel' (10730 KB)...
OKAY [  0.345s]
writing 'FOTAKernel'...
OKAY [  0.722s]
finished. total time: 1.075s

TWRP recovery mode application is installed, to assist flashing ROM.

ROM

A handful of ROMs exist. When choosing a ROM, also find the version of GApps that is suitable for the selected ROM. The Sony Xperia Z3 Compact uses a Snapdragon 801 Processor, which has a 32-bit architecture.

Note: These instructions have only been succesfully accomplished using CarbonROM and MindTheGapps.

CarbonROM 6.1

Download CarbonROM from:

Download the ARM architecture version of MindTheGapps from:

Alternatively, download the ARM architecture version of Open GApps from:

Skip to the General ROM Installation section.

LineageOS 15.1

Download LineageOS from (forum post):

Skip to the General ROM Installation section.

OmniROM Oreo 8.1

Download OmniROM Oreo from either of the following sites (forum post):

Continue to the General ROM Installation section.

General ROM Installation

The ROM filename will differ, depending on the ROM that was downloaded, such as:

• CarbonROM: CARBON-CR-6.1-NOCT-WEEKLY-z3c-20180605-0603.zip


• OmniROM: omni-8.1.0-20180320-z3c-nailyk.zip


• LineageOS: lineage-15.1-20171103-UNOFFICIAL.zip

The steps to flash a given ROM are as follows:

1. Reboot the phone using: fastboot reboot


2. Copy the file onto the smart phone (e.g., Computer\Xperia Z3 Compact\Internal storage\Download) using Xperia Companion


3. Power off phone


4. Unplug phone



5. Press and hold the volume down button


6. Press and hold the power button


7. Wait for a slight vibration before releasing both buttons


8. Wait for recovery application to load


9. Swipe to allow modifications


10. Select WIPE


11. Select Advanced


12. Check the following:
    
    
    
    • Dalvik / ART cache
    
    
    
    • System
    
    
    • Cache
    
    
    • Data
    
    
    
    


13. Swipe to confirm wipe


14. Tap Home icon


15. Tap Install


16. Browse to and select the OS ROM file


17. Tap Add more Zips



18. Browse to and select the GApps file


19. Swipe to confirm Flash


20. Tap Reboot System


21. Wait for the boot to complete

Android and the GApps are installed using the specified ROM.