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Use manual flash to test an updated image

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August 13, 2015

The Windows Embedded 8.1 Handheld manual flash feature allows you to test a full flash update (FFU) image containing fixes on a device without going through Microsoft Update. All of the data on the device will be wiped and replaced with the new image.

You should receive two FFU images from your OEM when testing a fix. One image contains the fix that needs to be tested. The other image allows you to roll the device back to the image that was on it before testing the fix.

Note that an updated FFU image affects the overall serviceability of the device. The main path reflects the official update path for a device that Microsoft Update supports. The fix path is a branch of the main path where the device is updated by using manual flash to test an update. After testing the image, return the device to the main path by flashing it back to an image on the main path.

For example, if your device has been updated to GDR update 2.0, you will need an RTM, GDR update 1.0, or GDR update 2.0 image to flash your device back to the main path. Then you can use Microsoft Update to bring the device back to a GDR update 2.0 state. However, you cannot leave a fix on the device and then use Microsoft Update to update the device because the FFU image containing the fix will disable Microsoft Update. This is because your device could become unusable if there is an incompatibility between the fix in the updated FFU image and an update installed via Microsoft Update. The following diagram illustrates the upgrade path for a device.

There are two ways to update a device. You can use an SD card that contains the updated FFU image, or you can connect the device to your desktop and use FFUTool.exe to update the image on the device. Both methods are discussed in the following sections.

Update a device using a SD card

You will need an SD card with about 2 GB of space to store the Flash.ffu image and a device that has an SD card reader. To update a device using a SD card:

  1. Plug in the device to a power source. Ensure that the device is powered until flashing is complete or the device may become unusable.

  2. Copy the FFU image containing the fix onto the root directory of the SD card. The image must be named Flash.ffu (the name is not case sensitive) and be signed by the OEM for the manual flash feature to recognize the image.

  3. On the device, choose Settings > Manual Flash to open the manual flash tool. The manual flash page appears:

  4. Insert the SD card containing Flash.ffu into the device. If the SD card does not contain Flash.ffu in the root directory, or Flash.ffu is not a valid Windows Embedded 8 Handheld image, a message notifies you that no valid Flash.ffu file was found on the SD card. If a valid Flash.ffu is available, the message Configuration received appears:

  5. Choose SD Card to flash the device by using the SD card. A message will warn you that all information on your device will be erased.You can press cancel and return to the previous page, or press ok to proceed with the flash.

  6. A final message informs you that you need to plug in your device. Plug in your device and press ok to flash the device.

  7. You will see Goodbye as your device powers off, and then the device will boot into flash mode. A lightning bolt will appear on the screen and the Flashu.ffu image on the SD card will be flashed onto the device. This process takes several minutes and there is no visual indication of progress. When the image is flashed onto your device, the device will boot into the out-of-box experience (OOBE) mode and you can set it up and test the image.

Update a device using FFUTool.exe

You will need a computer that has the Windows Phone 8.1 SDK installed, so that you’ll have the FFUTool.exe tool, and a device that has a USB connector that operates in USB function mode. To update a device using FFUTool.exe:

  1. Plug in the device to a power source. Ensure that the device is powered until flashing is complete or the device may become unusable.

  2. Connect the device to your computer using a USB cable.

  3. On the device, choose Settings > Manual Flash to open the manual flash tool. The manual flash page appears:

  4. Choose FFU Tool. A message will warn you that all information on your device will be erased. You can press cancel and return to the previous page, or press ok to proceed with the flash.

  5. A final message informs you that you need to plug in your device. Plug in your device and press ok to flash the device.

  6. You will see Goodbye as your device powers off, and then the device will boot into flash mode. A lightning bolt will appear on the screen.

  7. Run FFUTool.exe from your desktop by using the –flash parameter and a path to the Flash.ffu image that contains the fixes that you want to test. For example, FFUTool –flash c:\NewImageFromOEM\flash.ffu

    The flash process will take several minutes and there will be no visual indication of progress. When the image is flashed onto your device, the device will boot into the out-of-box experience (OOBE) mode and you can set it up and test the image.

Return the device to the main update path

The test image that you receive from your OEM will disable Microsoft Update. After testing the fix, you need to put an image from the main update path on the device so that the device can receive updates again via Microsoft Update.

The following instructions describe how to run FFUTool.exe to place the image that your OEM provided to roll your device back to the main update path.

  1. Put your device into flash mode by simultaneously pressing the power and volume up buttons. Your device will boot into a flash mode and a lightning bolt will appear on the screen.

  2. Run FFUTool.exe from your desktop by using the –flash parameter and a path to the Flash.ffu image that contains the image that will restore your device to the main update path. For example, FFUTool –flash c:\OriginalImageFromOEM\flash.ffu

    The flash process will take several minutes and there will be no visual indication of progress. When the image is flashed onto your device, the device will boot into the out-of-box (OOBE) experience mode and you can set it up and test the image. Microsoft Update can now update the device.