Sony Xperia Z1 during it's world premier at the IFA consumer electronics fair, 2013
Sony Corp's President and Chief Executive Officer Kazuo Hirai presents a new Sony Xperia Z1 smartphone during it's world premier at the IFA consumer electronics fair in Berlin, September 4, 2013.Reuters

Prolific custom smartphone software developers CyanogenMod team has released a new Android v4.4.4 KitKat CM11 M12 series custom ROM to the Sony's 2013 flagship smartphone, Xperia Z1.

The CM11 M12 custom ROM is based on the AOSP (Android Open Source Project) v4.4.4 KitKat OS and not the recently released Android 5.0 Lollipop. The company is still working on the new Android OS and has promised something special for the fans to welcome the upcoming holidays and the New Year.

Nevertheless, CM11 M12 is still more stable than previous M11 (Milestone) series update. Other than enhanced features, it is also said to fix last month's POODLE vulnerability found in SSL (Secure Socket Layer) v3 protocol of most Internet browsers. This vulnerability gives leeway for network attacker to cause connection failures and they can trigger the use of SSL 3.0 and then exploit this issue to steal sensitive data. [More information on POODLE vulnerability, HERE]

Prerequisites (things to remember before installing Custom ROM)

  • Though installing custom ROM improves the device's performance and UI experiences, it makes the company warranty void and they will no longer be liable to provide updates in future [users can restore warranty by flashing the device with stock-ROM].
  • Make sure the device is rooted before going forward for custom ROM installation.
  • This new CyanogenMod Android 4.4.4 KitKat CM11 M12 firmware has to be installed on the Sony Xperia Z1 (aka Honami) model only; if tried on other devices, it might get bricked [To check your device model: Go to Settings >> About phone >> model number]
  • Installation of custom ROM requires clearing of memory in the smartphone, so make sure to back all the data by installing Clockwork Mod (CWM) Recovery/ TWRP in the smartphone.
  • Users make sure they have installed USB drivers on the PC, or else your device (Sony Xperia Z1) will not be recognised by the computer.
  • Make sure your device has more than 80% battery, or else there is chance of smartphone getting temporarily bricked if the installation process is interrupted mid-way.

[Disclaimer: This procedure is very technical and should be performed by a person with sound knowledge of rooting (or manual software installation) Android devices. If the step-by-step installation process is not followed properly, there are chances of the smartphone getting bricked or being permanently irreparable. International Business Times, India Edition cannot be held responsible for any damage or claims from readers if the procedure does not yield the required results or if the smartphone is bricked. Hence, users are advised to proceed with caution.]

Step-by-step installation guide of CyanogenMod Android v4.4.4 KitKat CM11 M12 Custom ROM for Sony Xperia Z1:

Step 1: Download CyanogenMod Android v4.4.4 KitKat CM11 M12 Custom ROM (HERE) and Google Apps (HERE) into your PC.

Step 2: Connect Sony Xperia Z1 to PC via USB cord.

[Note: Before plugging the phone to the computer, be sure that you have installed USB driver software, if not, click HERE to download the firmware]

Step 3: Then, place Android v4.4.4 KitKat CM11 M12 Custom ROM zip file into the phone's SD card memory. [Note: Users are advised to paste the .zip file in SD card root, not in any other folder.]

[Note: Before users' begin installing the custom software, be sure that the device must have rooted and has installed ClockworkMod Recovery/TWRP tool.]

Step 4: Now, turn off the device and disconnect from the PC.

Step 5: Then perform the regular Recovery Mode sortie by press holding 'Volume (up)', 'Home' and 'Power' buttons.

Step 6: After entering the RECOVERY mode, clear the phone memory, by choosing 'wipe data/factory reset'.

[Note: use 'Volume' keys to navigate and 'Power' button to select options, while operating under Recovery Mode.]

Step 7: Now, clear the cache memory by selecting 'wipe cache partition'.

Step 8: Then to go back to ClockworkMod recovery, and select 'advanced' and tap 'wipe dalvik cache' [Note: This step is optional, but many recommend this procedure so that user will not face boot loops or any other errors in the middle of custom ROM installation].

Step 9: Again come back to main recovery screen and then tap 'install zip from SD card'.

Step 10: Then tap 'choose zip from sdcard' and go to Android 4.4.4 ROM .zip file in SD card and enter the installation process. Repeat the same procedure again to install the Google Apps. [Note: use 'Volume' keys to navigate and 'Power' button to select options.]

Step 11: Once done with the installation process, navigate to '+++++Go Back+++++' and re-start the device by opting 'reboot system now' seen in the recovery menu.

Now, your device (Sony Xperia Z1) will take a few minutes to complete the booting process.

Users then head to Settings >> select About phone to confirm the installation of CyanogenMod Android v4.4.4 KitKat CM11 M12 custom ROM.

[Credits: CyanogenMod.org]