Add a recovery mechanism to your Windows 10 IoT core image

Article
06/06/2023

You can add a recovery mechanism to your image with WinPE as a Safe OS and WIM files as Recovery SW from recovery partition, using the steps provided below.

See Windows 10 IoT Core Recovery for the details on the possible mechanisms.

Step 1 : Update device layout with recovery partition

In the devicelayout.xml file, you add a new partition MMOS with the following attributes

FAT32 filesystem
Atleast 2GB size ( to accommodate WinPE wim and recovery wims)
Partition type
- GPT : {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
- MBR : 0x07

Sample xml snippet given below for a GPT device (assumes a sector size of 512)

<Partition>
    <Name>MMOS</Name>
    <FileSystem>FAT32</FileSystem>
    <TotalSectors>4096000</TotalSectors>
    <Type>{ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}</Type>
</Partition>

Step 2 : Configure BCD settings

In this step, the newly added MMOS partition is defined as a bootable partition in the BCD settings and the recovery sequence is enabled and configured to boot into this partition. These settings are available in the below given packages that you can readily use. Select GPT or MBR packages based on your device.

Recovery.GPT-BCD package
Recovery.MBR-BCD package
- Recovery.BCD.xml declares the MMOS partition availability.
Recovery.GPT-BcdEdit package
Recovery.MBR-BcdEdit package
- Recovery.BcdEdit.cmd enables recovery sequence and configures to boot into the MMOS partition.

Step 3 : Prepare WinPE image

Windows 10 ADK Release 1709 contains the Windows 10 Preinstall Environment for all architectures (x86/amd64 and arm). For Windows 10 ADK Release 1809, you will need to install the Windows PE add-on for ADK. In this WinPE, you add the following

Recovery scripts used for recovery process on device
- startnet.cmd, startnet_recovery.cmd: predefined scripts from the templates directory (see templates\recovery).
- config files : generated files based on the device layout, placed at Build\<arch>\<bspname>\recovery.
Recovery customizations files (optional)
- RecoveryGUI.exe : Optional simple UI to hide the recovery shell prompt on the device. The recoveryGUI.exe can be a C++ application built for the target CPU or a .NET Framework 4 Windows from application. Newwinpe.cmd will have to be modified to add .NET Framework 4 capabilities to the WinPE image.
- pre_recovery_hook.cmd and post_recovery_hook.cmd: optional hooks to add additional actions before and after recovery process.
- Place these files in Source-<arch>\bsp\<bspname>\WinPEExt\recovery folder.
BSP drivers (optional)
- You may need to add bsp drivers to winpe image to boot/write to storage, on your device platform.
- Place the required drivers in Source-<arch>\bsp\<bspname>\WinPEExt\drivers folder.

You can create the WinPE image for the bsp with the above contents using New-IoTWindowsImage command in IoTCorePShell

New-IoTWindowsImage <product> <config>
(or) newwinpe <product> <config>

This script will output the winpe at Build\<arch>\<product>\<config>\winpe.wim.

Step 4 : Update Feature manifest file and OEMInputFile

Update the <bspname>FM.xml with the following changes (see QCDB410CFM.xml sample)

Include the new device layout package, specifying new SOC name, QC8016-R in the example below .

<DeviceLayoutPackages>
   <PackageFile SOC="QC8016-R" Path="%PKGBLD_DIR%" Name="%OEM_NAME%.QCDB410C.DeviceLayout-R.cab" />
   <PackageFile SOC="QC8016" Path="%BSPPKG_DIR%" Name="Qualcomm.QC8916.DeviceLayout.cab" />
</DeviceLayoutPackages>

Update the <productname>/TestOEMInput.xml (and RetailOEMInput.xml) with the following changes (see Recovery sample)
- Specify the SOC name as defined in the <bspname>FM.xml
```
<SOC>QC8016-R</SOC>
```
- Include the RECOVERY_BCD feature in the OEM section
```
<OEM>
...
<Feature>RECOVERY_BCD</Feature>
...
</OEM>
```

Update the oemcustomization.cmd to invoke the Recovery.BcdEdit.cmd

REM The below should be called on every boot
if exist C:\RecoveryConfig\Recovery.BcdEdit.cmd (
    call C:\RecoveryConfig\Recovery.BcdEdit.cmd
)

Step 5 : Build the recovery image using New-IoTRecoveryImage

# Build all packages
New-IoTCabPackage All
(or) buildpkg All
# Build the product image
New-IoTFFUImage <product> <config>
(or) buildimage <product> <config>
# Build the recovery image
New-IoTRecoveryImage <product> <config>
(or) buildrecovery <product> <config>

This will generate the recovery file as Flash_Recovery.ffu

Share via