Packer

Compresses a PS5 game dump into a single .ffpfsc image on your PC, checks it file by file against the dump, uploads it to the PS5 over FTP and gets ShadowMountPlus to mount it. It does on the PC what Game Compressor does on the console, but faster, and it never deletes the dump.

How a job runs

1. Compress. MkPFS 1.1.0 runs pack folder, producing an exFAT image inside a PFSC container (the layout Game Compressor calls "exFAT"). The image is written to .work-<TITLE>/ in the image folder and moved into place only when MkPFS finishes. For APR Emu games, MkPFS checks ampr_emu.index and creates it inside the dump folder if it's missing or invalid. That is the only write to the dump.
2. Verify. resources/deep_verify.py decompresses the image through MkPFS's own reader, walks the inner exFAT and compares every file byte for byte with the dump, in parallel. Any missing, extra, resized or different file fails the job, and nothing gets uploaded. "Compress again" deletes the bad image and rebuilds it.
3. Upload. One FTP transfer to <upload folder>/.<TITLE>.ffpfsc.packer-part. ShadowMountPlus ignores dot-files, so a partial file is never mounted. The upload resumes with REST after a drop, is size-checked, then renamed to <TITLE>.ffpfsc. An existing image of a different size is never overwritten.
4. Mount. The upload writes the same hints Game Compressor writes: image_sector=<TITLE>.ffpfsc:65536 in /data/shadowmount/autotune.ini and image_ro=<TITLE>.exfat in config.ini. Both files are backed up first to ~/.local/share/ps5-packer/backups/ and replaced atomically. It also adds the image to manual.lst, as Game Compressor does. Rewriting that file is what makes ShadowMountPlus scan; a new file in /data/homebrew alone can sit unnoticed for minutes. Packer then polls /user/app/<TITLE>/mount_img.lnk for up to five minutes, rewriting manual.lst every 30 s. If the mount isn't confirmed, "Check again" repeats this step.

Using it

• Drop a dump folder on the window, press Ctrl+O, or start it with folders as arguments: ps5-packer /path/to/PPSA01234-app.
• Settings (Ctrl+,) has the PS5 address and ports, the image folder, compression level, and whether to upload automatically after Verify.
• On first launch, "Install MkPFS" creates a private Python venv in ~/.local/share/ps5-packer/engine. Python 3 must be installed.

Development

npm install
npm run tauri dev        # desktop app
npm run dev              # browser preview with a simulated backend (src/lib/mock.js)
npx tauri build --bundles deb

Tests (src-tauri):

cargo test                                   # unit tests
PACKER_E2E_SCRATCH=<dir> cargo test -- --ignored

The ignored tests need <dir> to contain:

• mkvenv/: a venv with mkpfs==1.1.0 and pyftpdlib
• fake_ps5.py (copy from tests/)
• fakedump/PPSA00001-app

They run the whole pipeline against a local fake PS5: an FTP server answering like ftpsrv.elf (RNTO/DELE reply 226) and a stand-in ShadowMountPlus. The scenarios are a full run, an identical re-upload being skipped, a tampered image being blocked at Verify, "Compress again", and resuming an interrupted upload. Another ignored test checks that Cancel kills MkPFS promptly.

Notes

• The PS5's ftpsrv STOR doesn't truncate before writing, so small temp files are deleted before they're rewritten.
• Game Compressor 1.0.4's Validate can't remount images under ShadowMountPlus 1.7. It reads only the first line of mount_img.lnk, which 1.7 writes outermost-first. This doesn't affect Packer, which checks every line.