Here’s how to download and Flash the Sony Xperia XA Ultra Dual F3212 Stock ROM Flash (FTF firmware) using the Xperia Flash Engine on a Windows PC.
Requirements: Your Xperia ™ device must have at least 30 to 40% of your phone’s battery to process the flash.
Flash Sony Xperia XA Ultra Dual F3212 Stock Rome uses FlashTool
Step 1: Before we start the flashing procedure Download Sony Xperia XA Ultra Dual F3212 Drivers from the link and if you have already got your drivers installed please skip the step.
Step 2: Download and unzip the Sony Xperia XA Ultra Dual F3212 Stock ROM on your computer. After extraction of the zip file, you can view the same file (with the .ftf extension):
Step 3: Download and install the Sony Xperia Flashtool software on your computer (if you already have the Flash tool, you do not need to download it again).
Step 4: After installing the Sony Xperia Flash tool, open it from C: Drive>Flashtool.
Step 5: When you boot Sony XPP FlashTool the following screen looks like this:
Step 6: Now click the Flash button.
Step 7: Now you can see the Boot mode selection menu. Select Flashboot and click OK.
Step 8: Load the downloaded Xperia software (.ftf) into the flash utility to do that click the Load button
Step 9: Now select the firmware loaded.
Step 10: Now press the flash button to start the process.
Step 11: Turn off your Xperia Device now.
Step 12: Press n Hold the Volume down Button and use the USB cable to connect the device to the computer.
Step 13: After successfully connecting to your computer, you will be able to see the new message in the Xperia Flashtool.
Step 14: Flashing of Firmware will then begin and end in 5-10 minutes.
Step 15: As soon as the process ends, Disconnect the Device from the computer and Turn it On.
Loss of data: Flashing of firmware is always a process in which you can lose data. So back up your personal data before backing up your firmware.
Sony Xperia: If you are looking for basic software for your device, visit the Sony Stock software page for all devices.
Driver Sony Xperia ™: if you are looking for an original USB driver for your device, download the Sony USB driver for all your devices.
[*] Credit: Xperia Flash tool, created by Androxyde. So, come to them to create a full loan for free applications.