Installing Sailfish X on Xperia X using Windows

Please make sure you read the whole page of instructions before starting.

NOTE: If you have an Xperia XA2 device then you are reading wrong instructions. These are the correct ones.

IMPORTANT – Do not skip this step

Use your Xperia X some time with Android OS. Check that phone calls can be made and received, that you can browse the Internet with a mobile data connection (turn WLAN off) and that the camera works. You might also want to check the touch display, loudspeaker and microphone.. Use the same SIM card as will be used with Sailfish X.

What you need to begin

  1. A. Sony Xperia™ X Single SIM (F5121) or Sony Xperia™ X Dual SIM (F5122), verified to have an unlockable bootloader.
    B. Micro-USB data cable
    C. Internet connection
    D. Windows computer
    E. Sailfish X from Jolla shop.

What you need to do

1. Update to the latest Android software version

OPTION 1: If your device has its bootloader locked:
1.1.1 Update to the latest version of Android over the air using your phone. You can go to “Settings > System > About Phone > Software Update”.
1.1.2 You might need to do the “Over The Air” update multiple times, so after completing the update go to “Settings > System >  About Phone > Software Update” again and check for system updates.
1.1.3 after you are done updating, check in your phone’s Android version: “Settings > System > About phone > Build number”, and make sure the build number is (where xxx is 228 or higher), or is 34.4.A.yyy (where yyy can contain any number).

OPTION 2: If your device has its bootloader unlocked:
1.2.1 Download and install the Flash tool “Emma”  from Sony’s developer website to your Windows computer.

NOTE: Sony provides the Emma tool for Windows only.

1.2.2 Turn off your Xperia device. Leave it off for at least fifteen (15) seconds.
1.2.3 Hold down the ‘Volume Down’ button on the device while connecting your device to your computer via USB cable. The LED next to the speaker on the device should light up green.
1.2.4 Run the Emma tool and follow its instructions. Please make sure the build number is (where xxx is 228 or higher), or is 34.4.A.yyy (where yyy can contain any number).
1.2.5  Boot up your device to Android and go through the setup wizard (skipping as many steps as you can) until you see “Done”.
1.2.6  Remember to turn developer options on by tapping “Settings > System > About phone > Build version” multiple times. Then enable “USB debugging” in Settings > System > Developer options.
1.2.7  Shut down your device and get ready to install Sailfish X.

2. Install the fastboot driver

If your Windows finds the fastboot driver for you device automatically, you can skip to section 3. If the driver is not found you need to install the driver manually, here are the instructions to do so:

Note: The procedure below only does NOT work on Windows 10 with version 2004. Please upgrade your computer to version 20H2 (or any later version) and also install the cumulative updates after that. Check your Windows 10 version at Settings > System > About > Windows specifications (or at Settings > Update & Security > View update history).

2.0 While the device is off: Hold down the Volume Up button gently and connect your device to your computer via USB. The LED next to the speaker on the device should light up blue. If it turns green then disconnect the cable and try again.
2.1 Download the Xperia™ X fastboot drivers from Sony’s website.
2.2 Right click the file, and click “Extract” it to a directory.
2.3 Open the ‘Device Manager’:
2.3.1 On Windows 7, right-click the ‘Computer’ icon on the desktop and choose ‘Manage’. When the Computer Management application appears, choose the ‘Device Manager’ in the tree.
2.3.2 On Windows 8 & 10, Device Manager can be found by right-clicking the Start button, or by pressing Windows+X on the keyboard.
2.4 Find the ‘S1Boot Fastboot’ device in the tree. If it is not correctly installed, it will show a warning sign.
2.5 Right-click it and choose ‘Update driver’
2.6 then ‘Browse my computer for driver software’,
2.7 Select “Let me pick from a list of available drives on my computer”
2.8 Select “Show All Devices” and click next
2.9 Select “Have disk…”
2.10 Select “Browse …” and go to the directory where you extracted the driver package at step 2.2
2.11 Select the driver information file called ‘sa0114adb.inf’ in that directory and click “Open”
2.12 Click “OK”
2.13 Then you should see “Sony sa0114 ADB Interface Driver” in the “Model” list.
2.14 Click “Next”
2.15 Then you might see “Update Driver Warning” for this you need to select “Yes”
2.16 After this you should see “Windows has successfully updated your drivers” and you can click “Close”. Windows Device Manager has now the item “Sony sa0114” in the tree.
Now your device will be ready for unlocking.

3. Extract the Sailfish OS .zip file

3.1  You have purchased the Sailfish X license and are hence entitled to download the latest Sailfish OS .zip file from .  You can download newer versions later, too.

The zip files are like this:  Examples: and

3.2 Extract this file to a directory, resulting in a dozen of files. In that directory you can also find the fastboot binary (file: fastboot.exe) that will be needed in section 4.

4. Unlock the bootloader

4.0 In order to unlock the phone you need to get the unlock key (unlock code) that can be requested from Sony Open Devices website.

– scroll down the page
– select your device  Xperia™ X
– scroll down the updated page
– enter the IMEI code (from Settings menu) of your device to the line near the bottom of the page
– type your email address to the next line
– click “Submit” and the unlock code will appear
– copy the code to the text buffer of your computer.

After getting the key please follow the below actions to do the actual unlocking.

4.1  Enable “Developer options” by going to “Settings > System > About Phone” and tap the “Build Number” multiple times until you see a prompt saying “You are now a developer!”
4.2. Enable “OEM unlocking” and “USB debugging” from “Settings > System > Developer options” menu.

Note that your Xperia device must have an Internet connection when doing this.

4.3 Turn off your phone
4.4 Connect USB cable to PC
4.5 Press and hold volume up gently and connect the other end of the USB cable to your phone and wait for the LED to light up BLUE. If it turns green then disconnect the cable and try again.

4.6 When your device is connected (blue LED is lit), using Windows File Explorer go to the folder where you unzipped Sailfish OS in step 3.2 (as it has the file ‘fastboot.exe’). Press Shift, then right-click the folder background (not files) and select “Open command prompt to this directory” (Windows 7) or “Open PowerShell window here” (Windows 10).

NOTE 1: Windows 10 PowerShell requires the commands in the following way, e.g. “.\fastboot.exe devices”

NOTE 2: PowerShell can also be launched from Windows 10 search utility (near bottom left corner). Then proceed to the Sailfish folder using the ‘cd’ command.


4.7 Run the command shown in chapter 4 “Enter unlock key” of Sony instructions – but please pay attention to the slightly different command variants explained below. Use the unlock key from chapter 4.0. Do not forget to add the ‘0x’ prefix.

a) If you use the default command prompt (“cmd”)  of Windows:

fastboot -i 0x0fce oem unlock 0x<insert your unlock code>


b) If you use the Windows PowerShell:

./fastboot.exe -i 0x0fce oem unlock 0x<insert your unlock code>


NOTE: If the commands above should fail with an error message about the “-i” option, please try using the shorter command variants below:

a) If you use the default command prompt (“cmd”)  of Windows:fastboot oem unlock 0x<insert your unlock code>

b) If you use the Windows PowerShell:

./fastboot.exe oem unlock 0x<insert your unlock code>

IMPORTANT NOTE: Detach the USB cable, restart the device and let it boot up to Android UI – Please go through the startup wizard before turning the device off again.

5. Getting the Sony vendor binary images

5.1 Download the Sony binary image named for the Xperia™ X  here.
5.2 Unzip the file.
5.3 Copy the SW_binaries_for_Xperia_AOSP_M_MR1_3.10_v13_loire.img extracted from the zip and paste it to the same directory where you extracted the Sailfish OS .zip file. Once done, you should have SW_binaries_for_Xperia_AOSP_M_MR1_3.10_v13_loire.img in the same directory with fastboot.exe, flash-on-windows.bat, sailfish.img001 and some other files.

NOTE: do all the steps above regardless of the Android version you got while updating it, also in case of Oreo (Android 8).

6. Flashing Sailfish X to your Xperia™

Connect your device to your PC in Fastboot mode as follows:

NOTE: If your device is still connected and the blue LED lit from step 4.7 it is ok to keep it that way and skip to step 6.6 below.

6.1 Disconnect your Xperia™ device from your PC
6.2 Turn off the device. Leave it off for at least fifteen (15) seconds.
6.3 Connect one end of a USB cable to your PC
6.4 While holding the ‘Volume Up’ button gently, connect the other end of the USB cable to your Xperia™ device. The LED next to the speaker on the device should light up blue. If green, then disconnect cable and try again.
6.5 On Windows, fastboot drivers are needed to properly detect the device, as was needed for the unlocking process (step 4.7) . If you need to install them, see the instructions in section 2 above.

6.6  Using Windows File Manager go to your Sailfish folder (see step 3.2).
6.7 Double-click ‘flash-on-windows.bat’. A console window appears.
If Windows warns you that it ‘Protected your PC’ by stopping the script from launching, click ‘More Info’ then ‘Run anyway’.
6.8 Follow the instructions in the console window.
6.9 When flashing has finished, reboot your device into Sailfish X!


  1. How can I check if my Xperia™ device can be unlocked?
    See the Sony Open Devices website for detailed information for each Xperia™ device. Scroll down to the bottom of this page, then select your device:
    For the Xperia™ X (correct at the time of writing, Sony may update this information at any time):
    In your device, open the dialler and enter *#*#7378423#*#* to access the service menu.
    Tap Service info > Configuration > Rooting Status. If Bootloader unlock allowed says Yes, then your device can be unlocked. If it says No, or if the status is missing, then unlocking is not possible.

2.After flashing Sailfish X to my Xperia™, it gets stuck on the Sony logo when it is booting up, how can I fix it?
You should reflash the device with the instructions above. Make sure that you have the correct Vendor binary image from Sony (chapter 5).

  1. How does this affect my warranty with Sony?
    The effect of unlocking your phone does affect your warranty, so you should make sure that you read Sony’s warnings during the unlocking process thoroughly. We also recommend that you verify that all the hardware is working properly before unlocking their devices, as although getting repairs for existing faults under warranty may still be possible after unlocking, it will be much easier before.
  2. Can I restore Android to my Xperia™ device later on?
    The Flashing too “Emma” mentioned above can be used to wipe your device and restore Sony’s stock Android. However, when the bootloader is unlocked, special security keys are permanently removed which cannot be restored by Emma. For the impact of the loss of these keys, please check the Sony website.
  3. I am trying to unlock the boot loader of a new Xperia™ device with my Windows PC but there is no response to command “fastboot devices”. What should I do?
    The fastboot driver from Sony must be re-installed for each device. Therefore, connect your new device to your PC in the fastboot mode (i.e. so that the blue LED is lit) and repeat steps 2.3 to 2.16 above.