A RomM companion client for jailbroken PS5 consoles (etaHEN or onionHEN, with kstuff) and PS4 consoles (GoldHEN). Through my insatiable need to mod everything electronic I encounter, I had my 12.70 PS5 jailbroken the minute that P2JB was out. I maintain a RomM server to centralize all my legal ROMs, saves, and savestates, which all my devices sync with, and the PS5 needs similar treatment.

RommDeck lands this week. Your Steam Deck has been feeling left out, so it's getting the same treatment: the same sync, the same app, built for the Deck and working with RetroDECK and EmuDeck. It lives in its own repository, s0liton/RommDeck. Watch it if you want to know the moment it's out.

• Save and state sync
  • Monitors save file changes in the background, and uploads them as soon as they've changed. Periodic syncs also ensure that your PS4/5 always has the latest saves and save states.
  • A game's saves come down the moment it finishes downloading, so it's ready to play.
  • Save states only come down to an emulator that can load them (see Save states).
  • Optional: turn save sync off in setup or Settings to use RomM just for games.
• See what synced
  • An activity log and every save and state kept in sync, by platform, in the app and the Web UI. Settle conflicts and restore older versions from either.
  • Settings > Diagnostic bundle saves the logs for a bug report, with your server, names and addresses left out.
• Interactive library
  • Browse your RomM library from the RommPS app (or some other device via the Web UI), download games and BIOS files into the right emulator folders, and resolve save conflicts.
• BIOS and System File Sync
  • Get the BIOS files and system data you need to run your emulators properly.
• Pluggable emulator profiles and multiple emulators per platform
  • Fully customizable sync destinations, but includes frequently updated preset profiles for existing homebrew emulators.
  • Can sync games and saves and states for multiple emulators per platform (PS2 on RetroArch and PS5SX2 as an example) using hardlinks.
• Beautiful and Responsive UI
  • Based on mihawk-99's Vulkan homebrew apps and BlackBearReloaded's UI kit, we get a nice, responsive feel. So worth it, it looks 1000x better. 15+ different themes to pick from.
• Background Service
  • All operations are handled by a backend payload, which means syncing, downloading, and updating keep working in the background, so you can keep gaming.
• RomM API Compliant
  • RommPS is meant to strictly stick to RomM's API and method of syncing saves and states, ensuring we don't break anything and support RomM's latest features.
• Secure and Human-Coded
  • Each release is signed. The payload checks the signature before it updates itself, and ProsperoStore checks every download against the release's checksum. This app was primarily coded by a human, and will be frequently updated and maintained. AI was primarily used for explaining concepts, creating documentation, and converting data. Ya know, the tedious stuff.
• Easter Eggs
  • Check in the Settings, scroll the settings list, see if you find the X. This hint won't be here forever.

Having finally built this damn thing for the PS5, I tried to tame my excitement as I sat down to set up a RomM client on my Steam Deck. Grinning ear to ear, I set everything up and went to play my favorite game on PS2. The smile faded quickly as I realized that it didn't support PSX, PS2, and a shitload of other emulators. I restrained my self from throwing my Steam Deck at the tree outside my office window.

Anyway, here's a port of RommPS for the Steam Deck. It has full feature parity with the PS5 version, and will use RommPS as its upstream. It features an identical UI app to manage everything, and works with RetroDeck and EmuDeck configurations today. It also has a companion Decky plugin if you're too lazy to open the main app.

I guess we'll call it....RommDeck. Yeah, sure. Whatever. Enjoy it.

• A PS5 running etaHEN or onionHEN, or a PS4 running GoldHEN
• RomM 5.2.0 or newer (may work on older versions)
• Whichever other emulators you want

ProsperoStore	RecompStore

Download PPSA76677.zip from the releases page, unzip it and copy the PPSA76677 folder to /data/homebrew/ on the console. Launch RommPS and it will deploy the background service, and set itself to autostart with etaHen or onionHen.

If you'd rather run just the payload, without the app:

1. Download the latest romm-sync.elf from the releases page.
2. Send it to the console (or use whichever favorite tool you wish):

   nc -w 1 <ps5-ip> 9021 < romm-sync.elf

3. Set it up at http://<ps5-ip>:8780 from another device.

Experimental. The PS4 is currently considered experimental Needs GoldHEN 2.4b18.5 or newer, whose payload menu runs ELF payloads. R

1. Download the latest romm-sync-ps4.pkg from the releases page and install it with your package installer.
2. Open RommPS from the home screen. It copies its payload, romm-sync-ps4.elf, to /data/payloads/.
3. In GoldHEN Settings, open the payloader, pick romm-sync-ps4.elf and run it. Add it to the AutoRun queue there and it starts on every jailbreak.
4. Open RommPS again: it shows the web UI. It's also at http://<ps4-ip>:8780 from another device.

The app only installs the payload and shows the web UI; the payload does the syncing, in the background, whether or not the app is open. Without the package, copy romm-sync-ps4.elf to /data/payloads/ yourself (GoldHEN's FTP server, or make install-ps4 PS4_HOST=<ps4-ip>).

Note: Don't send the payload to GoldHEN's network loader on port 9090: GoldHEN 2.4 crashes on ELFs sent there. Make sure the console's date and time are set (GoldHEN can keep them updated), or HTTPS won't work.

RommPS starts with your HEN, and setup turns this on for you. Both HENs start payloads/romm-sync.elf when romm-sync.elf.auto_start sits next to it, and RommPS puts both in every HEN's folder on the console (/data/etaHEN/payloads and /data/OnionHEN/payloads), so switching HENs keeps working. If a payload manager like pldmgr has its own copy, that copy is kept up to date too. If you build it yourself, make install PS5_HOST=<ps5-ip> copies it over FTP (add PS5_FTP=ftp://<ps5-ip>:1337 PS5_HEN_DIR=/data/OnionHEN for onionHEN's FTP plugin).

• On the PS5, just update RommPS: from ProsperoStore (or other homebrew storefronts eventually), or by copying the new zip's folder over the old one. The background service comes with it, and RommPS swaps it in the next time you open it, once nothing is syncing or downloading. An older version never replaces a newer one.
• On the PS4, the payload updates itself from Settings.
• Dev builds (the dev-build pre-release) are for testing. The next release installs over one like any other update.

The setup wizard walks you through five steps:

1. Connecting to your server.
2. Approving the console in RomM, by scanning a QR code or entering a code.
3. Choosing which emulators to sync.
4. Checking what the first sync will do.
5. Choosing when to sync in the background.

Back up your saves before the first sync. Copy your emulator save folders to a computer or USB drive. RommPS keeps a local copy before replacing any file, but your own backup is the safest option.

If your RomM server sits behind a reverse proxy that asks for a client certificate (mutual TLS: Traefik, Pangolin, nginx, Caddy), give RommPS that certificate as a PKCS#12 file (.p12 or .pfx) before you connect:

• Web UI: in the setup's first step, open Client certificate (mTLS), pick the file, enter its password and choose Use this certificate. Later it's under Settings, Server. RommPS checks the file and the password right away and shows whose certificate it is and until when it's valid.

• By hand: copy the file into /data/romm-sync/ and add it to /data/romm-sync/config.json, then restart the payload. The path is relative to /data/romm-sync/, or absolute:

  "client_cert": "client.p12",
  "client_cert_password": "your password"

The certificate is only shown to your RomM server, never to GitHub (updates). The password is kept in config.json like RomM's token, and never shown by the web UI or put in diagnostics.

If the server turns the connection down, RommPS says so: that it wants a certificate, or that it didn't accept this one (wrong CA, expired, revoked).

Older .p12 files encrypted with RC2 (OpenSSL 1.x's default, older Windows exports) can't be read on the PS5. Export yours again with AES:

openssl pkcs12 -in old.p12 -nodes -legacy -out cert.pem   # OpenSSL 1.1: without -legacy
openssl pkcs12 -export -in cert.pem -out client.p12 -keypbe AES-256-CBC -certpbe AES-256-CBC -macalg sha256
rm cert.pem   # it holds the unencrypted key

Pangolin: its own login for a resource (SSO, PIN, password) happens in a browser, which RommPS can't do. Turn authentication off for the RomM resource, or add a rule that lets it through, and let the client certificate (checked by Traefik) and RomM's own login guard it.

RommPS has built-in profiles for most known emulators on the PS5, and will set the correct default game, save/save state, and bios directories for them. Since there is a huge influx of new emulators popping up, I will be doing my very best to keep up with them and add profiles accordingly.

Note: RommPS relies on your emulator NOT being sandboxed. Some emulators require a separate payload that must be launched to be able to access outside of the sandbox, so make sure you've followed their instructions to properly install. Sandboxed emulators will not be able to read games or save files.

The emulators listed below are those I've tested and have created profiles for to auto-detect them. You can also manually set the directories for each emulator/platform via the PS5 app or or the Web UI; you can use whichever emulators you wish.

Some users have recently reported issues with being able to pull down save states from their servers. They don't see them on the destination save folder for that emulator, or if they do, they don't work. Save states typically cannot be used across different emulators (cores), and even within the same core, the definition of a save state may different with the file version, and version of the app. In my opinion, save states should be for quick resume or to save you when you forgot to save your game, so they truly don't need to be synced across devices.

PS2 saves go up as one 8 MB card per game holding only that game's saves, which is what RomM's own argosy-sigil makes, so Argosy and friends can load them. By default, RommPS gives each game its own card in PS5SX2 and RetroArch's PS5SX2 core (it writes the game's settings for you, no menu diving required), copies the game's saves over from the shared card, and leaves the shared card alone. Slot 2 stays shared, for the games that go looking for another game's save. Nothing on a card changes while the emulator is open.

PSP, GameCube and Wii saves are synced as one zip per game, the same format other RomM clients use.

If you are interested in downloading PS4 and PS5 games from your RomM server, RomM has direct FPKGi support, simply add it as a library. This sync client does NOT handle PS4/PS5 save syncing at this time, but is being researched for potential future inclusion.

RommPS exposes a separate Web UI at http://your-ps5-ip:8780 where you can access all the same features present in the native app.

I've included direct support for most of the emulators that are out right now, except for the ones that won't even launch... you can sync games, states, and saves anywhere you want, but the presets should do it for most people. You can also configure the paths for all platforms manually. The web UI has a JSON editor for your emulator profiles.

A game RomM keeps as a folder comes down without what RomM files as a manual, walkthrough, soundtrack, screenshot or cheat, and without the readmes, artwork and checksums (.txt, .nfo, .pdf, .jpg, .png, .sfv and friends) lying loose next to its files. Anything in a folder of the game's own comes down: that's game data (PS3_GAME/ICON0.PNG, a Wii U game's content), not box art. PC games (Windows, DOS, Linux, Mac, Steam, ScummVM) get every file, since half their config lives in .txt files. To decide for yourself, set "keep_all_files" on a platform entry ({"romm": ["psx"], "dir": "psx", "keep_all_files": true}) or on the whole profile: true brings every file, false leaves the extras on RomM wherever they are.

Both consoles build from the same code in src/. What differs lives in platform/<console>/: platform.c (the src/platform.h interface), the make rules and the Docker SDK image. platform/console/ has the parts the PS4 and PS5 share, and platform/host/ is the development build.

make host tools       # macOS or Linux build for development, plus tools/release-sign
tools/ps5-build.sh    # PS5 build in Docker, output in build/ps5/
tools/ps4-build.sh    # PS4 payload in Docker, output in build/ps4/
tools/ps4-build.sh ps4-pkg   # plus the PS4 home screen app (platform/ps4/app)
tests/e2e.sh          # end-to-end tests against a mock RomM server
tests/autostart.sh    # autostart, version checks and HEN folders

I've started streaming the development of this app as well as other side projects on my YouTube channel. Nothing serious, but you can catch me live streaming. ;)

My Channel

If buying isn't owning, then piracy isn't stealing. 🖕

GPL-3.0. Parts of the console code are adapted from ftpsrv and websrv by John Törnblom. cJSON and qrcode-generator are MIT licensed. Monocypher is CC0 or BSD-2-Clause. argosy-sigil is MPL-2.0, with tiny-AES-c (Unlicense).