MkPFS.C#

Build, check, and repair PS4/PS5 PFS game images (.ffpfs, .ffpfsc, .exfat) from the command line or a desktop app.

MkPFS.C# is a .NET 10 port of the Python MkPFS by PSBrew. It ships as a native executable (no Python needed), writes the same images as the original, and adds an offline PFSC block repair ported from PS5 Game Compressor.

Features

• Pack: a game folder, an exFAT image, or any single file into a compressed .ffpfsc (PFSC, zlib), or a folder into a plain PFS image (--raw, with signed, encrypted, 64-bit inode, and PS4 options).
• exFAT: build exFAT images from game folders (deterministic, 64 KiB clusters by default).
• Batch: pack every game folder and image in a folder in one run.
• Check: verify, inspect, tree, and unpack for PFS, PFSC, and exFAT images, including encrypted ones (--ekpfs-key).
• Repair: find and fix compressed blocks the PS5 may decode wrongly (images made with ISA-L).
• APR Emu: ampr_emu.index is created or refreshed automatically for games that use it.
• GUI: mkpfs-gui with a page per command, cover and metadata preview, batch queue, and a PFSC block map; English, Português (BR), and Español.

Download

Get the archive for your system from the releases page and unpack it anywhere:

System	Command line	Desktop app
Windows x64	mkpfs-<version>-win-x64.zip	mkpfs-gui-<version>-win-x64.zip
Linux x64	mkpfs-<version>-linux-x64.tar.gz	mkpfs-gui-<version>-linux-x64.tar.gz
macOS Apple silicon	mkpfs-<version>-osx-arm64.tar.gz	mkpfs-gui-<version>-osx-arm64.tar.gz

• Keep each program in its folder with the libraries next to it (mkpfs_zlib, plus Skia and HarfBuzz for the desktop app).
• macOS: the desktop app is MkPFS.C#.app. It is not notarized, so open it the first time with right-click > Open.
• Linux: the desktop app needs X11 and fontconfig, which desktop distributions include.
• SHA256SUMS.txt on the release page lists the archive checksums.
• Check the command line with mkpfs selftest.

Usage

All paths may be absolute or relative to the current directory. Replace values in angle brackets with your own paths; square brackets indicate an optional argument. Run mkpfs <command> --help for the parser's built-in help.

Commands at a glance

Command	Arguments	Default result	Purpose
pack folder <source_dir> <image_file>	game/homebrew folder, output path	exFAT wrapped in a compressed .ffpfsc	Package a game folder.
pack file <source_file> <image_file>	input file, output path	compressed .ffpfsc	Package one file in a PFS container.
pack exfat <source_dir> [output]	game/homebrew folder, optional output path	<titleId>.exfat beside the source	Build an uncompressed exFAT image.
batch <source_dir> <output_dir>	directory of folders/images, destination directory	one .ffpfsc per discovered item	Package many inputs; existing outputs are skipped.
verify <image_file>	image path	—	Validate an image, optionally against its source.
inspect <image_file>	image path	text report	Show image metadata and integrity information.
tree <image_file>	folder or image path	outer tree	List files and directories.
unpack <image_file> <output_dir>	image path, destination directory	—	Extract an image.
repair <image_file>	single-file .ffpfsc path	repairs risky blocks	Repair PFSC blocks that a PS5 may decode incorrectly.

Common examples

Pack a game folder into a .ffpfsc (wrapped in exFAT and compressed in one pass):

mkpfs pack folder PPSA12345-app PPSA12345.ffpfsc

Compress an existing exFAT image:

mkpfs pack file PPSA12345.exfat PPSA12345.ffpfsc

Pack a folder directly as PFS (--signed, --encrypted, --inode-bits 64, and --version PS4 apply here):

mkpfs pack folder PPSA12345-app PPSA12345.ffpfs --raw

Build an exFAT image from a game folder:

mkpfs pack exfat PPSA12345-app PPSA12345.exfat

Pack every game folder and image file in a folder (existing outputs are skipped):

mkpfs batch ./games ./output

Verify an image against its source:

mkpfs verify PPSA12345.ffpfsc --source-file PPSA12345.exfat

Show image details (--format json for scripts):

mkpfs inspect PPSA12345.ffpfsc

List the files, including inside a wrapped exFAT:

mkpfs tree PPSA12345.ffpfsc --deep

Extract the game files:

mkpfs unpack PPSA12345.ffpfsc out --deep

Repair blocks the PS5 may decode wrongly in a single-file .ffpfsc:

mkpfs repair PPSA12345.ffpfsc

pack folder and pack file

Both commands require a source path and an output image path. By default, the output extension is changed to .ffpfsc when necessary. The default build is PS5, 32-bit inodes, case-insensitive, zlib level 7, 64 KiB blocks, and compression enabled. Direct-PFS folder builds and single-file builds also run a quick structure verification by default. The default exFAT-wrapped folder flow runs a post-pack check only when --verify is supplied.

For the default exFAT-wrapped pack folder flow, compression remains enabled and the PFS block size remains 64 KiB. Use --raw to make options that control direct PFS layout or compression (--no-compress, --block-size, --inode-bits, --max-compressed-ratio, --min-compress-size, and --skip-executable-compression) take effect.

Option	Default	Meaning
--adjust-output-file-extension	on	Change the requested output extension to match the selected pack mode.
--no-adjust-output-file-extension	off	Keep the output filename exactly as supplied. Cannot be combined with --adjust-output-file-extension.
--compress / --no-compress	compression on	Enable or disable PFSC block compression. The two flags are mutually exclusive.
--threshold-gain <0-100>	0	Keep a compressed block only when it saves at least this percentage.
--block-size <bytes|auto|auto-fit>	auto (65536)	PFS block size; it must be a power of two from 4096 through 2097152. auto-fit is supported by folder packing and the spool path to reduce file-data padding.
--temp-folder <dir>	system temporary directory	Where staged pack artifacts are written.
--version <PS4|PS5>	PS5	PFS profile version.
--inode-bits <32|64>	32	PFS inode-width mode.
--case-sensitive / --case-insensitive	case-insensitive	Select the PFS name-comparison mode. The two flags are mutually exclusive.
--cpu-count <n>	0 (automatic)	PFSC compression workers. Automatic mode uses up to 16 workers and leaves one logical CPU free; a nonzero value is clamped to at least one.
--compression-level <0-9>	7	zlib compression level.
--compression-backend <auto|zlib-ng|zlib|isal>	auto	Compatibility option. This port always uses zlib 1.3.1; unsupported values produce a warning.
--max-compressed-ratio <0-100>	100	Do not use PFSC when its stored size exceeds this percentage of the raw file size.
--min-compress-size <bytes>	resolved block size	Store smaller files raw without attempting PFSC compression.
--skip-executable-compression	off	Do not compress important executable files.
--signed	off	Build a signed PFS using a zero EKPFS/seed. It is not supported by the default exFAT-wrapped folder mode.
--encrypted	off	Encrypt filesystem blocks with AES-XTS.
--ekpfs-key <64-hex>	all-zero key	EKPFS key for an encrypted image; it requires --encrypted.
--verbose	off	Print per-file decisions.
--dry-run	off	Scan and report the planned layout without writing an image.
--verify	off	Run full post-pack verification instead of the default structure-only check.
--verify-structure / --no-verify-structure	structure check on	Explicitly enable or disable the default quick post-pack check. The two flags are mutually exclusive.
--skip-verification	off	Skip all post-pack verification. It cannot be combined with --verify.

pack folder also accepts the following options:

Option	Default	Meaning
--raw	off	Package the source directly as a PFS .ffpfs, rather than making the default exFAT-wrapped .ffpfsc. Use this mode for --signed, --inode-bits 64, and other direct-PFS settings.
--require-game-files	off	Refuse to pack unless sce_sys/param.json and eboot.bin are present.
--no-ampr-index	off	Do not create ampr_emu.index when fakelib/libSceAmpr.sprx is present.
--ampr-skip-regen-if-exists	off	When AMPR generation applies, retain a valid existing index.
--ampr-force-regen	off	Regenerate an existing AMPR index.

pack file also accepts:

Option	Default	Meaning
--use-spool	off	Force the legacy staged/spool builder instead of direct-to-image streaming.
--rename-inner-image / --no-rename-inner-image	rename on	Normalize the filename stored inside the image (the first flag explicitly selects the default), or preserve the source filename.

pack exfat

mkpfs pack exfat <source_dir> [output] creates an uncompressed exFAT image. If output is omitted, the program derives <titleId>.exfat beside the source directory; an output directory is also accepted and receives that derived filename.

Option	Default	Meaning
--cluster-size <bytes|auto>	auto (65536)	exFAT cluster size. The automatic 64 KiB value is optimized for SMP/LVD.
--overwrite	off	Replace an existing output image.
--verbose	off	Print detailed packing output.
--no-progress	off	Hide the progress bar written to standard error.

batch

mkpfs batch <source_dir> <output_dir> discovers packable folders and image files in source_dir and writes .ffpfsc images into output_dir. It skips existing outputs by default. Its compression, PFS-profile, naming, and encryption options have the same meanings and defaults as the corresponding pack options: --compress/--no-compress, --threshold-gain, --block-size (auto = 65536; auto-fit is not accepted), --version, --inode-bits, --case-sensitive/--case-insensitive, --cpu-count, --compression-level, --compression-backend, --max-compressed-ratio, --min-compress-size, --skip-executable-compression, --encrypted, --ekpfs-key, and --verbose.

Option	Default	Meaning
--overwrite	off	Replace images that already exist in the output directory.
--dry-run	off	Report the conversions without writing images.
--verify	off	Run full verification for each successful image.
--compress / --no-compress	compression on	Enable or disable compression; these flags are mutually exclusive.

Reading and extracting images

Encrypted read commands accept --ekpfs-key <64-hex> (default: all-zero key) and --new-crypt (default: off) to select the alternate EKPFS derivation. verify, tree, and unpack also take --format <auto|pfs|exfat>; the default auto detects the format from the input.

Command	Options	Default	Meaning
inspect <image_file>	--format <text|json>	text	Select a human-readable or JSON metadata report.
tree <image_file>	--deep	off	For a PFS that wraps one exFAT image, list the files inside that exFAT.
unpack <image_file> <output_dir>	--overwrite	off	Replace an existing output path.
	--deep	off	Extract files from an inner exFAT image instead of only the outer PFS contents.
	--only <inner-path>	none; repeatable	With --deep, extract only the named inner exFAT file or directory.
	--no-progress	off	Hide extraction progress on standard error.
verify <image_file>	--source-dir <dir>	none	Compare hierarchy and payloads against a source folder. Cannot be combined with --source-file.
	--source-file <file>	none	Compare a single-file image to the source file; not supported for exFAT input.
	--expect-crc32 <hex>	none	Require this cumulative payload CRC32.
	--expect-manifest-sha256 <64-hex>	none	Require this manifest SHA256 digest.
	--require-game-files	off	Warn when sce_sys/param.json, eboot.bin, or pfs-version.dat is missing.

repair

repair operates on an unsigned, unencrypted, single-file .ffpfsc. By default it scans for risky compressed blocks, stores replacements raw, verifies their decoded content, and cleans unused bytes in the outer PFS wrapper.

Option	Default	Meaning
--scan	off	Report only; do not modify the image. Returns exit code 3 if blocks need repair.
--bad-blocks <file>	none	Repair the block numbers in a PS5 Game Compressor bad_blocks.tsv instead of the scan's risky-block selection.
--recompress	off	Re-encode repaired blocks with zlib level 7 instead of storing them raw.
--mode <auto|in-place|copy>	auto	auto copy-replaces when free space is at least 1.2× the image, otherwise rewrites in place. in-place can leave an interrupted image corrupt; copy always uses a replacement copy.
--report-dir <dir>	none	Write summary.json and bad_blocks.tsv to this directory.
--no-slack-cleanup	off	Leave unused bytes in the outer PFS wrapper unchanged.
--cpu-count <n>	0 (all cores)	Worker count for scanning and repair.
--no-progress	off	Hide progress output.

Exit code 0 means success, 1 means an operation failed, 2 means invalid command-line usage, and repair --scan uses 3 when it finds blocks that need repair.

GUI

mkpfs-gui runs the same commands from a window and shows their output and progress. From a source checkout:

dotnet run --project src/MkPFS.Gui -c Release

• Pick a game folder or image to see its cover, title, IDs, version, region, and APR Emu marker.
• The Batch page lists every item it will pack before you run it.
• Pack File, Pack Folder, and Batch have compression presets (Fast, Balanced, Max, Low RAM) and settings for the zlib level, CPU cores, block size, and when to keep blocks uncompressed.
• The Repair page scans an image and draws a block map (zlib, raw, risky); click a cell for its offset, stored size, and largest back-reference distance.

Differences from Python MkPFS

• Same inputs give the same images as Python MkPFS 1.0.0 run with its zlib backend. Set SOURCE_DATE_EPOCH for reproducible timestamps.
• Compression always uses zlib 1.3.1 at level 7. --compression-backend is accepted but ignored: ISA-L output uses back-references the PS5 decodes wrongly.
• repair is new.
• Bugs found in the Python version while porting are listed in tools/oracle/README.md; some are fixed here.
• Switching from Python MkPFS: see MIGRATION.md.

Build from source

Requirements:

• .NET SDK 10.0.401 or a newer 10.0.4xx (see global.json).
• Windows: Visual Studio 2026 with "Desktop development with C++" (native zlib and Native AOT).
• Linux and macOS: CMake and a C compiler; Linux Native AOT also needs clang and zlib1g-dev.

Build and test:

dotnet build MkPFS.slnx

dotnet test --solution MkPFS.slnx

The first build compiles the bundled zlib in native/. Parity tests skip when the oracle corpus (tests/fixtures/generated) is missing.

Publish native executables:

dotnet publish src/MkPFS.Cli -r win-x64 -c Release

dotnet publish src/MkPFS.Gui -r win-x64 -c Release

Use linux-x64 or osx-arm64 on those systems. On Windows, Native AOT linking needs the Visual Studio Installer folder (C:\Program Files (x86)\Microsoft Visual Studio\Installer) on PATH.

Project layout

Path	Content
src/MkPFS.Core	Formats and codecs: PFS, PFSC, exFAT, AMPR, crypto, readers, validators
src/MkPFS.Build	Image builders, compression planner, batch
src/MkPFS.Repair	PFSC repair (Game Compressor port)
src/MkPFS.Cli	mkpfs command line
src/MkPFS.Gui	mkpfs-gui desktop app (Avalonia)
native/	zlib 1.3.1 and the mkpfs_zlib shim
tests/MkPFS.Tests	Unit tests
tests/MkPFS.Parity	Byte-for-byte tests against the Python oracle corpus
tests/MkPFS.Gui.Tests	GUI view model and headless UI tests
tools/oracle	Python oracle scripts (README)

Oracle corpus

The parity tests compare against images and logs made by Python MkPFS. With Python MkPFS checked out at ../MkPFS and uv installed:

uv run --project ../MkPFS python tools/oracle/build_goldens.py --check

Releases

Push a version tag to publish a release. The workflow reruns CI, then uploads the archives, SHA256SUMS.txt, and release notes, and marks the release as latest. With a VT_API_KEY repository secret (a VirusTotal API key), it also scans every archive and links the reports in the notes.

git tag v2.0.0

git push origin v2.0.0

Credits

• MkPFS by PSBrew: the Python original this port follows.
• PS5 Game Compressor by Juma Sayeh: the PFSC repair logic.
• Drakmor's APR Emu: the ampr_emu.index format.

Third-party components:

• zlib 1.3.1 (zlib license)
• Avalonia, CommunityToolkit.Mvvm, System.CommandLine, and Spectre.Console (MIT)
• Material Design Icons (Apache-2.0)

License

GPL-3.0-only, same as MkPFS. See LICENSE.md.

This project is not affiliated with Sony Interactive Entertainment.