CreateVhdxFromIso.ps1

# Parameter help description
param(
    [Parameter(ParameterSetName = "SRC", Mandatory = $true, ValueFromPipeline = $true)]
    [Alias("ISO")]
    [string]
    [ValidateNotNullOrEmpty()]
    [ValidateScript({ Test-Path $(Resolve-Path $_) })]
    $IsoPath,

    [Parameter(ParameterSetName = "SRC")]
    [Alias("VHD")]
    [string]
    [ValidateNotNullOrEmpty()]
    $VhdxPath,

    [Parameter(ParameterSetName = "SRC")]
    [Alias("Size")]
    [UInt64]
    [ValidateNotNullOrEmpty()]
    [ValidateRange(512MB, 64TB)]
    $SizeBytes = 50GB,

    [Parameter(ParameterSetName = "SRC")]
    [Alias("Index")]
    [UInt64]
    [ValidateNotNullOrEmpty()]
    [ValidateRange(1, 10)]
    $ImageIndex = 4          #defaults to datacenter editions with GUI   
)

$BCDBoot = "bcdboot.exe"
$VHDFormat = "VHDX"
$TempDirectory = $env:Temp

function
Write-ActionInfo {
    # Function to make the Write-Host output a bit prettier. 
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [string]
        [ValidateNotNullOrEmpty()]
        $text
    )
    Write-Host "INFO   : $($text)" -ForegroundColor White
}

function
Start-Executable {
    <#
            .SYNOPSIS
                Runs an external executable file, and validates the error level.

            .PARAMETER Executable
                The path to the executable to run and monitor.

            .PARAMETER Arguments
                An array of arguments to pass to the executable when it's executed.

            .PARAMETER SuccessfulErrorCode
                The error code that means the executable ran successfully.
                The default value is 0.  
        #>

    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $true)]
        [string]
        [ValidateNotNullOrEmpty()]
        $Executable,

        [Parameter(Mandatory = $true)]
        [string[]]
        [ValidateNotNullOrEmpty()]
        $Arguments,

        [Parameter()]
        [int]
        [ValidateNotNullOrEmpty()]
        $SuccessfulErrorCode = 0

    )

    Write-ActionInfo "Running $Executable $Arguments"
    $ret = Start-Process           `
        -FilePath $Executable      `
        -ArgumentList $Arguments   `
        -NoNewWindow               `
        -Wait                      `
        -RedirectStandardOutput "$($TempDirectory)\$($scriptName)\$($sessionKey)\$($Executable)-StandardOutput.txt" `
        -RedirectStandardError  "$($TempDirectory)\$($scriptName)\$($sessionKey)\$($Executable)-StandardError.txt"  `
        -PassThru

    Write-ActionInfo "Return code was $($ret.ExitCode)."

    if ($ret.ExitCode -ne $SuccessfulErrorCode) {
        throw "$Executable failed with code $($ret.ExitCode)!"
    }
}

Write-ActionInfo "Creating virtual hard disk..."
$newVhd = New-VHD -Path $VhdxPath -SizeBytes $SizeBytes -Dynamic

Write-ActionInfo "Mounting $VHDFormat..."
$disk = $newVhd | Mount-VHD -Passthru | Get-Disk


# UEFI : 3 partitions : efi - msr - windows
<#https://learn.microsoft.com/de-de/windows/win32/api/winioctl/ns-winioctl-partition_information_gpt
PARTITION_BASIC_DATA_GUID - ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
PARTITION_SYSTEM_GUID - c12a7328-f81f-11d2-ba4b-00a0c93ec93b    # EFI
PARTITION_MSFT_RESERVED_GUID - e3c9e316-0b5c-4db8-817d-f92df00215ae  # MSR
PARTITION_MSFT_RECOVERY_GUID - de94bba4-06d1-4d40-a16a-bfd50179d6ac   # Recovery partition (Windows) we are not using this
#>

try {
    Write-ActionInfo "Initializing disk..."
    Initialize-Disk -Number $disk.Number -PartitionStyle GPT

    Write-ActionInfo "Creating EFI system partition..."
    $systemPartition = New-Partition -DiskNumber $disk.Number -Size 200MB -GptType '{ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}'
                
    Write-ActionInfo "Formatting EFI system volume..."
    $systemVolume = Format-Volume -Partition $systemPartition -FileSystem FAT32 -Force -Confirm:$false

    Write-ActionInfo "Setting EFI system partition PARTITION_SYSTEM_GUID..."
    $systemPartition | Set-Partition -GptType '{c12a7328-f81f-11d2-ba4b-00a0c93ec93b}'
    $systemPartition | Add-PartitionAccessPath -AssignDriveLetter
         
    # Create the reserved partition 
    Write-ActionInfo "Creating MSR partition..."
    $reservedPartition = New-Partition -DiskNumber $disk.Number -Size 128MB -GptType '{e3c9e316-0b5c-4db8-817d-f92df00215ae}' -Verbose

    # Create the Windows partition
    Write-ActionInfo "Creating windows partition..."
    $windowsPartition = New-Partition -DiskNumber $disk.Number -UseMaximumSize -GptType "{ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}"
        
    Write-ActionInfo "Formatting windows volume..."
    $windowsVolume = Format-Volume -Partition $windowsPartition -FileSystem NTFS -Force -Confirm:$false

    # Assign drive letter to Windows partition.  This is required for bcdboot
    $windowsPartition | Add-PartitionAccessPath -AssignDriveLetter
    $windowsDrive = $(Get-Partition -Volume $windowsVolume).AccessPaths[0].substring(0, 2)
    Write-ActionInfo "Windows path ($windowsDrive) has been assigned."

    # Refresh access paths (we have now formatted the volume)
    $systemPartition = $systemPartition | Get-Partition            
    $systemDrive = $systemPartition.AccessPaths[0].trimend("\").replace("\?", "??")
    Write-ActionInfo "System volume location: $systemDrive"

    # Mount .iso to get the install.wim
    $beforeMount = (Get-Volume).DriveLetter -split ' ' 
    $mountResult = Mount-DiskImage -StorageType ISO -ImagePath $IsoPath
    $afterMount = (Get-Volume).DriveLetter -split ' '
    $setuppath = (Compare-Object $beforeMount $afterMount -PassThru ) 
    Write-ActionInfo "Mounted .iso to $($setuppath):"

    Write-ActionInfo "Applying image from .iso $("$setuppath"+":\sources\install.wim") to $VHDFormat. This could take a while..."

    Expand-WindowsImage -ApplyPath $windowsDrive -ImagePath "$setuppath`:\sources\install.wim" -Index $ImageIndex #-LogPath "$($logFolder)\DismLogs.log" | Out-Null
    Write-ActionInfo "Image was applied successfully. "

    Write-ActionInfo "Making image bootable..."                                   
    $bcdBootArgs = @(
        "$($windowsDrive)\Windows", # Path to the \Windows on the VHD
        "/s $systemDrive", # Specifies the volume letter of the drive to create the \BOOT folder on.
        "/v"                        # Enabled verbose logging.
    )
    $bcdBootArgs += "/f UEFI"   # Specifies the firmware type of the target system partition

    Start-Executable -Executable $BCDBoot -Arguments $bcdBootArgs

    Write-ActionInfo "Drive is bootable.  Cleaning up..."

    # Remove system partition access path, if necessary
    $systemPartition | Remove-PartitionAccessPath -AccessPath $systemPartition.AccessPaths[0]
}
finally {
    Write-ActionInfo "Dismounting $VHDFormat..."
    Dismount-VHD -Path $VhdxPath

    #ejecting .iso - releasing drive letter.
    Write-ActionInfo "Dismounting .iso..."
    Dismount-DiskImage -ImagePath $IsoPath
}