A no-fork RomM client for stock muOS (MustardOS). Wireless library mirroring, download-on-launch, and automatic save sync — delivered entirely through muOS's own extension surfaces (an Application, launch overrides, and a boot-init hook). Stock muOS stays stock: nothing in the firmware is patched or replaced.

Validated target: Anbernic RG34XX (Allwinner H700, arm64) on muOS 2601 "Jacaranda".

• Mirror your RomM library — every game on your server appears in the muOS menus (0-byte stubs for games not yet on the card), with box art.
• Download on launch — pick a game you don't have; it downloads over Wi-Fi (hash-verified), then launches. Already-downloaded games launch instantly, offline.
• Automatic save sync — saves are pulled before play and pushed after (or queued offline and pushed later by a charging-gated background daemon). Play the same game across devices without thinking about it.
• On-device onboarding — a built-in wizard (framebuffer UI) walks through server pairing on first launch; later launches offer Sync-now / re-setup.

The launch override only wraps RetroArch folders (decided from muOS's own info/assign config); standalone systems (PSP, etc.) are never touched. Launching a game is never gated on sync — if anything network-side fails, the game still runs.

The sync engine and wizard are CGO-free static Go binaries (muOS variant is the muos build tag):

cd engine
CGO_ENABLED=0 GOARCH=arm64 go build -tags muos -trimpath -ldflags "-s -w" ./cmd/lodor-sync
CGO_ENABLED=0 GOARCH=arm64 go build -tags muos -trimpath -ldflags "-s -w" ./cmd/lodor-wizard

The release pipeline (release/release.sh) builds both, gates them (static, branding, PII, redistributable), and assembles Lodor-muOS-<version>.muxapp.

1. Copy Lodor-muOS-<version>.muxapp to ARCHIVE/ on SD1 (/mnt/mmc/ARCHIVE).
2. On the device: Applications → Archive Manager → install it.
3. Launch Lodor from Applications. The wizard walks you through pairing with your RomM server (e.g. https://romm.example.com) and the initial mirror. Wi-Fi setup stays in muOS Settings — connect first.

Configuration lives in the app folder (config.json; see config.json.example). The app ships the public Mozilla CA bundle (certs/ca-certificates.crt) so HTTPS verification works on-device.

App/Lodor/
  mux_launch.sh          # muOS app entry → onboarding wizard / sync menu
  lodor-sync             # headless engine (built artifact, muos-arm64)
  lodor-wizard           # framebuffer onboarding UI (built artifact, arm64)
  lib/romm-sync-lib.sh   # shared shell library (env contract, Wi-Fi, corename lookup)
  bin/lodor-override.sh  # launch override: stub-fetch → save-pull → stock launcher → save-push
  bin/lodor-seed.sh      # (re)installs overrides + boot hook; idempotent
  bin/romm-run           # app → engine bridge (network bring-up, logging)
  bin/romm-syncd         # charging-gated offline save-push daemon
  certs/                 # public Mozilla CA bundle
  glyph/                 # app icon
test/
  check.sh               # shell-surface gate (parse + shellcheck)
  integ-harness.sh       # end-to-end sandbox harness (real card image, qemu engine)
  mockromm.go            # loopback RomM stand-in for the offline harness legs

muOS has no MinUI-style recent.txt; its History menu (muxhistory) renders one pointer file per game under MUOS/info/history (/run/muos/storage/info/history at runtime) — <name>-<FNV1a-32-of-path>.cfg, three lines (rom path / system folder / content name), ordered by file mtime. The engine's --sync-continue (the fast "Sync now" leg; the full Refresh runs the same delivery) materializes the cross-device RomM feed as those pointer files, mtime-stamped to each save's server updated_at — games played on another device surface in muOS's own History, in true recency order, with zero launcher changes. Injected entries launch through the standard assign/override pipeline, so download-on-launch and the save bracket apply. Pointers the engine did not create are never touched (the user's real history is sacred); a stale Lodor pointer stranded by the ✘→✓ download rename is re-keyed to the live name.

• BYOB: no BIOS or firmware is bundled, ever. Use the engine's --download-bios against your own server's collection.
• Saves are matched per libretro corename (read from the card's own core .info files), exactly where stock RetroArch reads them.

• lodor — the sync engine (all releases publish there too)
• lodoros — the MinUI-fork flagship for Miyoo devices
• lodor-nextui — the NextUI (TrimUI) pak
• lodor-knulli — the Knulli (Batocera-family) port