Add support for custom temporary directories in image creation scripts

New-OsfExfatImage.ps1

@@ -24,6 +24,13 @@
          -Label "DATA" `
          -ForceOverwrite
 
+    2b) Custom temp directory (large copies / slow system drive):
+       powershell.exe -ExecutionPolicy Bypass -File .\New-OsfExfatImage.ps1 `
+         -ImagePath "D:\images\data.img" `
+         -SourceDir "C:\payload" `
+         -TempDir "D:\temp" `
+         -ForceOverwrite
+
     3) Create empty image and keep mounted (manual format/copy):
        powershell.exe -ExecutionPolicy Bypass -File .\New-OsfExfatImage.ps1 `
          -ImagePath "C:\images\data.exfat" `
@@ -38,6 +45,8 @@
     -Size            Optional. If omitted, an optimal size is computed to fit all files.
                      Suffixes: K/M/G/T (1024), k/m/g/t (1000), b (512-byte blocks), or bytes.
     -Label           Volume label.
+    -TempDir         Optional. Directory for temporary files (format.com logs, etc.).
+                     Aliases: -t. When omitted, Windows default temp is used.
     -ForceOverwrite  Recreate image if it already exists.
     -CreateEmptyAndMount
                      Create and mount image only. Skip format/copy and leave mounted.
@@ -64,6 +73,9 @@ param(
 
   [string]$Label = "OSFIMG",
 
+  [Alias("t")]
+  [string]$TempDir,
+
   [switch]$ForceOverwrite,
 
   [switch]$CreateEmptyAndMount
@@ -123,6 +135,36 @@ function Parse-SizeToBytes([string]$s) {
   throw "Failed to parse size string: '$s'"
 }
 
+$script:ScriptTempDir = $null
+
+function Initialize-ScriptTempDir([string]$dir) {
+  if ([string]::IsNullOrWhiteSpace($dir)) { return }
+  $resolved = $dir.Trim()
+  if (-not (Test-Path -LiteralPath $resolved -PathType Container)) {
+    throw "Temp directory not found: $resolved"
+  }
+  $resolvedPath = (Resolve-Path -LiteralPath $resolved).Path
+  $probe = Join-Path $resolvedPath ([System.IO.Path]::GetRandomFileName())
+  try {
+    Set-Content -LiteralPath $probe -Value "" -NoNewline
+    Remove-Item -LiteralPath $probe -Force -ErrorAction SilentlyContinue
+  } catch {
+    throw "Temp directory is not writable: $resolvedPath"
+  }
+  $script:ScriptTempDir = $resolvedPath
+  $env:TEMP = $script:ScriptTempDir
+  $env:TMP = $script:ScriptTempDir
+  Write-Host "[Info] Temp directory: $script:ScriptTempDir"
+}
+
+function New-ScriptTempFile {
+  if ($script:ScriptTempDir) {
+    $name = [System.IO.Path]::GetRandomFileName()
+    return (Join-Path $script:ScriptTempDir $name)
+  }
+  return [System.IO.Path]::GetTempFileName()
+}
+
 function Format-Bytes([Int64]$bytes) {
   if ($bytes -ge 1TB) { return "{0:N2} TB" -f ($bytes/1TB) }
   if ($bytes -ge 1GB) { return "{0:N2} GB" -f ($bytes/1GB) }
@@ -255,8 +297,8 @@ function Invoke-FormatVolume([string]$driveLetter, [int]$clusterSize, [string]$l
   $lastFormatExitCode = -1
   foreach ($attempt in $attempts) {
     Write-Host "[Info] format attempt: $($attempt.Name)"
-    $stdoutPath = [System.IO.Path]::GetTempFileName()
-    $stderrPath = [System.IO.Path]::GetTempFileName()
+    $stdoutPath = New-ScriptTempFile
+    $stderrPath = New-ScriptTempFile
     try {
       $proc = Start-Process -FilePath "format.com" -ArgumentList $attempt.Args -Wait -PassThru -NoNewWindow `
         -RedirectStandardOutput $stdoutPath -RedirectStandardError $stderrPath
@@ -295,6 +337,8 @@ if (-not (Test-Admin)) { throw "Please run PowerShell as Administrator." }
 if (-not (Test-Path $SourceDir -PathType Container)) { throw "Source directory not found: $SourceDir" }
 if (-not (Test-Path (Join-Path $SourceDir "eboot.bin") -PathType Leaf)) { throw "eboot.bin not found in source directory: $SourceDir" }
 
+Initialize-ScriptTempDir -dir $TempDir
+
 # Ensure output directory exists
 $outDir = Split-Path -Parent $ImagePath
 if ($outDir -and -not (Test-Path $outDir)) {

make_image.bat

@@ -2,13 +2,45 @@
 setlocal EnableExtensions
 
 REM make_image.bat
-REM Usage: make_image.bat "C:\images\data.exfat" "C:\payload"
+REM Usage: make_image.bat [-t tmp_dir|--tmp-dir tmp_dir|--temp-dir tmp_dir] "C:\images\data.exfat" "C:\payload"
 
-if "%~1"=="" goto :usage
-if "%~2"=="" goto :usage
+set "IMAGE="
+set "SRCDIR="
+set "TEMPDIR="
 
-set "IMAGE=%~1"
-set "SRCDIR=%~2"
+:parse_args
+if "%~1"=="" goto :parse_done
+if /i "%~1"=="-t" goto :take_temp
+if /i "%~1"=="--tmp-dir" goto :take_temp
+if /i "%~1"=="--temp-dir" goto :take_temp
+if /i "%~1"=="-h" goto :usage
+if /i "%~1"=="--help" goto :usage
+if not defined IMAGE (
+  set "IMAGE=%~1"
+  shift
+  goto :parse_args
+)
+if not defined SRCDIR (
+  set "SRCDIR=%~1"
+  shift
+  goto :parse_args
+)
+echo [ERROR] Too many arguments.
+goto :usage
+
+:take_temp
+if "%~2"=="" (
+  echo [ERROR] Missing value for %~1
+  goto :usage
+)
+set "TEMPDIR=%~2"
+shift
+shift
+goto :parse_args
+
+:parse_done
+if not defined IMAGE goto :usage
+if not defined SRCDIR goto :usage
 
 REM Script is expected to be in the same directory as this BAT
 set "SCRIPT=%~dp0New-OsfExfatImage.ps1"
@@ -29,10 +61,21 @@ if not exist "%SRCDIR%\eboot.bin" (
   exit /b 4
 )
 
+if defined TEMPDIR (
+  if not exist "%TEMPDIR%\" (
+    echo [ERROR] Temp directory not found: "%TEMPDIR%"
+    exit /b 5
+  )
+)
+
 REM Run elevated? This BAT does not auto-elevate.
 REM Right-click -> Run as administrator, or start cmd as admin.
 
-powershell.exe -NoProfile -ExecutionPolicy Bypass -File "%SCRIPT%" -ImagePath "%IMAGE%" -SourceDir "%SRCDIR%" -ForceOverwrite
+if defined TEMPDIR (
+  powershell.exe -NoProfile -ExecutionPolicy RemoteSigned -File "%SCRIPT%" -ImagePath "%IMAGE%" -SourceDir "%SRCDIR%" -TempDir "%TEMPDIR%" -ForceOverwrite
+) else (
+  powershell.exe -NoProfile -ExecutionPolicy RemoteSigned -File "%SCRIPT%" -ImagePath "%IMAGE%" -SourceDir "%SRCDIR%" -ForceOverwrite
+)
 
 set "RC=%ERRORLEVEL%"
 if not "%RC%"=="0" (
@@ -45,7 +88,12 @@ exit /b 0
 
 :usage
 echo Usage:
-echo   %~nx0 "C:\path\to\image.img" "C:\path\to\folder"
+echo   %~nx0 [-t tmp_dir ^| --tmp-dir tmp_dir ^| --temp-dir tmp_dir] "C:\path\to\image.img" "C:\path\to\folder"
+echo.
+echo Examples:
+echo   %~nx0 "D:\out\game.exfat" "C:\payload"
+echo   %~nx0 -t D:\temp "D:\out\game.exfat" "C:\payload"
+echo   %~nx0 "D:\out\game.exfat" "C:\payload" --temp-dir D:\temp
 echo.
 echo Notes:
 echo   - Run this BAT as Administrator.

mkexfat.sh

@@ -1,17 +1,75 @@
 #!/bin/sh
 # For WSL2/Ubuntu/Debian: sudo apt-get install -y exfatprogs exfat-fuse fuse3 rsync
 # Create an exFAT image from a directory
-# Usage: mkexfat.sh <input_dir> [output_file]
+# Usage: mkexfat.sh [-t tmp_dir|--tmp-dir tmp_dir] <input_dir> [output_file]
 
 set -e
 
-if [ -z "$1" ]; then
-    echo "Usage: $0 <input_dir> [output_file]"
+TMP_BASE="/tmp"
+INPUT_DIR=""
+OUTPUT=""
+
+usage() {
+    echo "Usage: $0 [-t tmp_dir|--tmp-dir tmp_dir|--temp-dir tmp_dir] <input_dir> [output_file]"
+}
+
+while [ $# -gt 0 ]; do
+    case "$1" in
+        -t|--tmp-dir|--temp-dir)
+            if [ -z "$2" ]; then
+                echo "Error: missing value for $1"
+                usage
+                exit 1
+            fi
+            TMP_BASE="$2"
+            shift 2
+            ;;
+        -h|--help)
+            usage
+            exit 0
+            ;;
+        --)
+            shift
+            while [ $# -gt 0 ]; do
+                if [ -z "$INPUT_DIR" ]; then
+                    INPUT_DIR="$1"
+                elif [ -z "$OUTPUT" ]; then
+                    OUTPUT="$1"
+                else
+                    echo "Error: too many positional arguments"
+                    usage
+                    exit 1
+                fi
+                shift
+            done
+            break
+            ;;
+        -*)
+            echo "Error: unknown option: $1"
+            usage
+            exit 1
+            ;;
+        *)
+            if [ -z "$INPUT_DIR" ]; then
+                INPUT_DIR="$1"
+            elif [ -z "$OUTPUT" ]; then
+                OUTPUT="$1"
+            else
+                echo "Error: too many positional arguments"
+                usage
+                exit 1
+            fi
+            shift
+            ;;
+    esac
+done
+
+if [ -z "$INPUT_DIR" ]; then
+    usage
     exit 1
 fi
 
-INPUT_DIR="$1"
-OUTPUT="${2:-test.exfat}"
+OUTPUT="${OUTPUT:-test.exfat}"
 
 if [ ! -d "$INPUT_DIR" ]; then
     echo "Error: input directory not found: $INPUT_DIR"
@@ -23,6 +81,15 @@ if [ ! -f "$INPUT_DIR/eboot.bin" ]; then
     exit 1
 fi
 
+if [ ! -d "$TMP_BASE" ]; then
+    echo "Error: temp directory not found: $TMP_BASE"
+    exit 1
+fi
+if [ ! -w "$TMP_BASE" ] || [ ! -x "$TMP_BASE" ]; then
+    echo "Error: temp directory is not writable/executable: $TMP_BASE"
+    exit 1
+fi
+
 # More accurate sizing for exFAT:
 # - file payload rounded to cluster size
 # - FAT + allocation bitmap estimates from cluster count
@@ -84,13 +151,26 @@ echo "Input size (exFAT alloc): $DATA_BYTES bytes"
 echo "Files: $FILE_COUNT, Dirs: $DIR_COUNT"
 echo "exFAT profile: -c $MKFS_CLUSTER_ARG (avg file=$AVG_FILE_BYTES bytes)"
 echo "Image size: ${MB}MB"
+echo "Temp directory: $TMP_BASE"
 
 truncate -s "${MB}M" "$OUTPUT"
 mkfs.exfat -c "$MKFS_CLUSTER_ARG" "$OUTPUT"
-mkdir -p /mnt/exfat
-mount -t exfat-fuse -o loop "$OUTPUT" /mnt/exfat
-rsync -r --info=progress2 "$INPUT_DIR"/ /mnt/exfat/
+MOUNT_DIR=$(mktemp -d "$TMP_BASE/mkexfat.XXXXXX")
+
+cleanup() {
+    if mountpoint -q "$MOUNT_DIR" 2>/dev/null; then
+        umount "$MOUNT_DIR" || true
+    fi
+    rmdir "$MOUNT_DIR" 2>/dev/null || true
+}
 
-umount /mnt/exfat
+trap cleanup EXIT INT TERM
+
+# exfat-fuse can open a plain file without a kernel loop device.  mount -o loop
+# uses libmount/losetup and can fail on some removable exFAT targets (~large images).
+if ! mount -t exfat-fuse "$OUTPUT" "$MOUNT_DIR"; then
+    mount -t exfat-fuse -o loop "$OUTPUT" "$MOUNT_DIR"
+fi
+rsync -r --info=progress2 "$INPUT_DIR"/ "$MOUNT_DIR"/
 
 echo "Created $OUTPUT"