compress_idr.ps1

[CmdletBinding()]
param(
    [string]$InputSys      = "$PSScriptRoot\rsc\kvc.sys",
    [string]$OutputFile    = "$PSScriptRoot\src\IDR_DRV1",
    [string]$InputBbs      = "$PSScriptRoot\rsc\bbs.exe",
    [string]$OutputFile2   = "$PSScriptRoot\src\IDR_DRV2",
    [string]$SetupManager  = "$PSScriptRoot\src\SetupManager.c"
)

Set-StrictMode -Version 3.0
$ErrorActionPreference = "Stop"

Add-Type -TypeDefinition @"
using System;
using System.Runtime.InteropServices;

public static class Lznt1 {
    const ushort COMPRESSION_FORMAT_LZNT1   = 2;
    const ushort COMPRESSION_ENGINE_MAXIMUM = 0x0100;

    [DllImport("ntdll.dll")]
    static extern int RtlGetCompressionWorkSpaceSize(
        ushort CompressionFormatAndEngine,
        out uint CompressBufferWorkSpaceSize,
        out uint CompressFragmentWorkSpaceSize);

    [DllImport("ntdll.dll")]
    static extern int RtlCompressBuffer(
        ushort CompressionFormatAndEngine,
        byte[] UncompressedBuffer,
        uint   UncompressedBufferSize,
        byte[] CompressedBuffer,
        uint   CompressedBufferSize,
        uint   UncompressedChunkSize,
        out uint FinalCompressedSize,
        IntPtr WorkSpace);

    public static byte[] Compress(byte[] input) {
        ushort format = COMPRESSION_FORMAT_LZNT1 | COMPRESSION_ENGINE_MAXIMUM;
        uint wsSize, fragSize;
        int status = RtlGetCompressionWorkSpaceSize(format, out wsSize, out fragSize);
        if (status != 0) throw new Exception(string.Format("RtlGetCompressionWorkSpaceSize: 0x{0:X8}", (uint)status));

        IntPtr ws = Marshal.AllocHGlobal((int)wsSize);
        try {
            byte[] outBuf = new byte[input.Length + 4096];
            uint finalSize;
            status = RtlCompressBuffer(format, input, (uint)input.Length,
                                       outBuf, (uint)outBuf.Length,
                                       4096, out finalSize, ws);
            if (status != 0) throw new Exception(string.Format("RtlCompressBuffer: 0x{0:X8}", (uint)status));
            byte[] result = new byte[finalSize];
            Array.Copy(outBuf, result, (int)finalSize);
            return result;
        } finally {
            Marshal.FreeHGlobal(ws);
        }
    }
}
"@

[byte[]]$XorKey = 0xA0, 0xE2, 0x80, 0x8B, 0xE2, 0x80, 0x8C

# ---------------------------------------------------------------------------
# IDR_DRV1  --  kvc.sys
# ---------------------------------------------------------------------------

$raw        = [System.IO.File]::ReadAllBytes((Resolve-Path $InputSys).Path)
$compressed = [Lznt1]::Compress($raw)

for ($i = 0; $i -lt $compressed.Length; $i++) {
    $compressed[$i] = $compressed[$i] -bxor $XorKey[$i % $XorKey.Length]
}

[System.IO.File]::WriteAllBytes($OutputFile, $compressed)

$ratio = [math]::Round((1 - $compressed.Length / $raw.Length) * 100, 1)
Write-Host "--- IDR_DRV1 (kvc.sys) ---" -ForegroundColor Cyan
Write-Host "Input  : $($raw.Length) bytes  ($InputSys)" -ForegroundColor Cyan
Write-Host "Output : $($compressed.Length) bytes  ($OutputFile)  [-$ratio%]" -ForegroundColor Green
Write-Host ""

# ---------------------------------------------------------------------------
# IDR_DRV2  --  bbs.exe
# ---------------------------------------------------------------------------

$rawBbs        = [System.IO.File]::ReadAllBytes((Resolve-Path $InputBbs).Path)
$compressedBbs = [Lznt1]::Compress($rawBbs)

for ($i = 0; $i -lt $compressedBbs.Length; $i++) {
    $compressedBbs[$i] = $compressedBbs[$i] -bxor $XorKey[$i % $XorKey.Length]
}

[System.IO.File]::WriteAllBytes($OutputFile2, $compressedBbs)

$ratioBbs = [math]::Round((1 - $compressedBbs.Length / $rawBbs.Length) * 100, 1)
Write-Host "--- IDR_DRV2 (bbs.exe) ---" -ForegroundColor Cyan
Write-Host "Input  : $($rawBbs.Length) bytes  ($InputBbs)" -ForegroundColor Cyan
Write-Host "Output : $($compressedBbs.Length) bytes  ($OutputFile2)  [-$ratioBbs%]" -ForegroundColor Green
Write-Host ""

# ---------------------------------------------------------------------------
# Patch SetupManager.c — replace only the numeric value on each #define line,
# preserving the existing whitespace alignment between the name and the value.
# ---------------------------------------------------------------------------

$smPath = (Resolve-Path $SetupManager).Path
$content = [System.IO.File]::ReadAllText($smPath)

$content = $content -replace '(#define kvc_SIZE\s+)\d+',              "`${1}$($compressed.Length)"
$content = $content -replace '(#define kvc_UNCOMPRESSED_SIZE\s+)\d+', "`${1}$($raw.Length)"
$content = $content -replace '(#define bbs_SIZE\s+)\d+',              "`${1}$($compressedBbs.Length)"
$content = $content -replace '(#define bbs_UNCOMPRESSED_SIZE\s+)\d+', "`${1}$($rawBbs.Length)"

[System.IO.File]::WriteAllText($smPath, $content)

Write-Host "SetupManager.c updated:" -ForegroundColor Yellow
Write-Host "  kvc_SIZE              = $($compressed.Length)"
Write-Host "  kvc_UNCOMPRESSED_SIZE = $($raw.Length)"
Write-Host "  bbs_SIZE              = $($compressedBbs.Length)"
Write-Host "  bbs_UNCOMPRESSED_SIZE = $($rawBbs.Length)"