brave-fencer-musashi-decomp-port

An experimental PC port of Brave Fencer Musashi (PlayStation, USA, SLUS-00726). You play from your own disc; no game data or BIOS is included. The current runtime is hybrid: compiled host code plus a CPU interpreter. The fully native port remains a development goal.

Source update — 2026-10-29 (decompilation only, no new build): 1,340 more owner-authored functions in src/ (300 main-executable, 1,040 scene overlay), each independently re-derived from the retail disassembly and rebuilt byte-exact against the retail code with the pinned compiler. See EXCLUDED.md ("2026-10-29 source update") and SCANS.md for what was added, what was held back and the scans. These files are decompilation progress: the published builds do not compile them natively unless they are on config/lane_own_code_allow.txt, and the runtime is unchanged. The newest public test build is still bfm-r55-ba90b87ad (2026-10-20, prerelease, Linux x86_64), a hybrid build in which code that is not converted runs on the built-in CPU interpreter. Work toward a fully native runtime continues privately as development diagnostics: it is not playable, and nothing here claims a native or complete port.

Earlier test build — r47, 2026-10-16 (prerelease): Linux x86_64 and Windows x64 are available now in bfm-r47-8f8176c8c (bfm-r47-8f8176c8c-linux-x86_64.tar.gz, bfm-r47-81c5dbd03-windows-x64.zip). It is r41 plus the game's VSync wait running as native code. It is still a hybrid test build: it passed boot tests, but the full route, speed and handheld checks were not run. The Windows build has run under Wine only, not on real Windows.

Latest stable release — r38, 2026-10-02: Linux x86_64. Forest rendering fixes and isolated inn save/cold Continue checks passed. The instructions below use r38.

Previous Windows x64 test build — r44, 2026-10-05: bfm-r44-c427ee546-windows-x64.zip is available in the bfm-r41-3634893fe test prerelease. It has been validated under Wine only, not on real Windows. The same prerelease also has a newer Linux r41 test build. Whole-game completion and full graphics/audio fidelity are unverified.

About this project

This is a passion project. I'm working hard on it, but it's made for fun and for everyone's enjoyment — free, non-commercial, and made by a fan. If you enjoy it, that's the whole point.

Milestones and progress

Public releases mark selected improvements; an entire milestone may still be in progress. The Milestones wiki page defines each milestone and records segment status and a dated changelog.

Next milestone: Chapter 1 playable end to end, with saving.

How to play

These instructions match bfm-r38-61c60516d. Read the setup guide for prerequisites, controls, saves and troubleshooting.

Linux x86_64

Download bfm-r38-61c60516d-linux-x86_64.tar.gz and SHA256SUMS from the release page into the same directory, then:

sha256sum -c SHA256SUMS
mkdir -p "$HOME/Games/bfm-port"
tar -xzf bfm-r38-61c60516d-linux-x86_64.tar.gz -C "$HOME/Games/bfm-port"
"$HOME/Games/bfm-port/bfm-r38-61c60516d/launch.sh"

Requires glibc 2.38+, a C++ runtime with GLIBCXX_3.4.32, OpenGL and the desktop graphics/audio libraries listed in the setup guide. Put a .cue/.bin dump of your own USA SLUS-00726 disc in ~/Games/brave-fencer-musashi/disc/ or a disc/ folder beside launch.sh. Keep all referenced tracks together. One-bin and per-track dumps work; a 2048-byte .iso does not. A file picker is offered when available, or set BFM_DISC="/path/to/your/game.cue" when launching.

To try the r47 test build instead, use bfm-r47-8f8176c8c-linux-x86_64.tar.gz and the SHA256SUMS from the r47 release page in the same steps, and run bfm-r47-8f8176c8c/launch.sh. Its launch.sh turns the native VSync wait on; MUSASHI_VSYNC_WAIT=off runs the r41 wait.

For Steam Deck/Game Mode, add launch.sh as a non-Steam game and keep Steam Input enabled. Preserve earlier version folders and back up saves after quitting normally; no running game needs to be updated or restarted.

Windows x64 (test build, Wine-validated only)

Download bfm-r44-c427ee546-windows-x64.zip and SHA256SUMS from the bfm-r41-3634893fe release page. This build was cross-compiled for Windows 10/11 x64 and has run only under Wine. It has not been tested on real Windows hardware. Its native-lane function set is the same as Linux r41.

The newer r47 Windows test build, bfm-r47-81c5dbd03-windows-x64.zip, installs the same way from the r47 release page; its hash is in SHA256SUMS-windows-x64 there. It has also run only under Wine.

1. Optional: check the download in PowerShell with Get-FileHash bfm-r44-c427ee546-windows-x64.zip -Algorithm SHA256. Compare the result with the line in SHA256SUMS.
2. Extract the zip to a folder you control, for example %USERPROFILE%\Games\bfm-port.
3. Put the .cue/.bin dump of your own USA SLUS-00726 disc in a disc\ folder next to launch.cmd, or in %USERPROFILE%\Games\brave-fencer-musashi\disc. Keep all referenced tracks together. If neither folder has a disc, a file picker asks once. You can also set BFM_DISC to the .cue path.
4. Run launch.cmd. Saves go to %APPDATA%\bfm-port (memory card bfm_card0.mcd). The log of the last run is %APPDATA%\bfm-port\last-run.log.

The package README says controls and the dev menu work as in the Linux build: F8 or Select+Start opens the menu, and BFM_DEV_MENU=0 turns it off. That has not been re-checked on a Windows machine. See Windows notes.

Controls, saves and dev menu

• Gameplay: D-pad/left stick or arrows/WASD; controller A/B/X/Y correspond to Cross/Circle/Square/Triangle, or keyboard C/V/X/Z. Enter is Start; Space is Select. Full controls.
• Save using the game's menus. The default Linux card is ~/.local/state/bfm-port/bfm_card0.mcd; BFM_SAVE_DIR selects a separate card directory. Inn save and cold Continue passed isolated tests. Save/config locations and limitations.
• The packaged dev menu is enabled by default, with cheats initially off. Open with F8 or Back/Select+Start on one controller. Navigate with Up/Down or D-pad/left stick; Enter/A selects, Esc/B goes back. F1 is help. The game keeps running while the menu is open.
• The menu offers 29 warp destinations, an empty Finish Area page, HP/BP refills, Drans/time actions, fast-forward and screenshots. See the current Dev Menu wiki for exact options, effects and precautions.

The log is ~/.local/state/bfm-port/last-run.log by default. See troubleshooting. General config.ini settings are not reliably loaded by r38; the setup guide lists working launcher controls instead.

Status

r38 fixes forest frames going dark and includes tested inn saving and cold Continue. Forest, village and the recorded four-scene attract route passed scoped checks. Attract still stops at known refusal 800495ec; later unsupported code may also stop. Automated checks used null audio, and do not establish hardware audio fidelity or whole-game completion.

The goal remains a faithful, fully native port. Original rendering is the release default. Cheats start off, even though the dev menu is enabled. Milestones and known divergences distinguish completed checks from remaining work.

Build from source

Source snapshot limitation: the public r38 tag points to sanitized snapshot ec620c78dd5f68a166f6565f7c2d8539e9c378a0; its runtime binaries were built from 61c60516d18bf6402e6dbd937d8c8d18ebd1af4b. GitHub's automatic source archives and the historical build instructions below do not reproduce the newer r38 binary. The Windows x64 binary was cross-built from unpublished port sources (windows-port c427ee546); this recipe does not build it. Public player instructions above describe the release artifact, not the older source snapshot's menu behavior.

This repository holds the port (pc_port/), its tools (tools/), tests, configuration and documentation, and the owner-authored matched C that the port compiles natively (src/main/, 252 functions, with their entries in provenance/matches.json: addresses, sizes and source paths only). All of it is the owner's original work. See EXCLUDED.md for what is left out and why.

Matched C is a reimplementation of the game's own code, written so that the original compiler reproduces the original machine code. It is published for study, interoperability and preservation, like other matching decompilations; it does not grant any rights in Brave Fencer Musashi.

The r38 release binary is built with -DMUSASHI_NATIVE_LANE=ON -DMUSASHI_LANE_OWN_CODE_ONLY=ON. With these options the native lane compiles only owner-authored matched C listed in config/lane_own_code_allow.txt (guest addresses only). Everything else runs interpreted from your own disc, including every function whose recorded origin names the upstream decompilation or Sony/Psy-Q code. The commands below describe the older sanitized source snapshot. Its historical function counts do not describe r38; the current release's admitted sources passed the no-m2c-macro guard.

A build needs the following:

1. Linux build dependencies: CMake, a C/C++ compiler and clang, Python 3, SDL2, OpenAL Soft, OpenGL, OpenSSL (libcrypto), and optionally zlib.

2. PsyCross (MIT). ./tools/fetch_toolchains.sh fetches it at the pinned commit e56e4cd into tools/third_party/psycross/. The same script also fetches maspsx, m2c and the old-gcc compilers used by the matching tools. Then apply the port's local PsyCross edits (MIT): git -C tools/third_party/psycross apply ../../patches/psycross-local.patch (the patch is tools/patches/psycross-local.patch, made against e56e4cde). ./tools/fetch_lua.sh fetches Lua for mod scripts. This step is optional.

3. Your own disc, at build time. tools/native_lane_gen.py reads extracted/disc/files/SLUS_007.26 and extracted/overlays/main/0003.bin to verify what it compiles. The tools create both files from your disc:

   # dumpsxiso from https://github.com/Lameguy64/mkpsxiso, built into
   # tools/third_party/mkpsxiso/build/; chdman (MAME) on PATH
   python3 tools/register_retail.py "/path/to/Brave Fencer Musashi (USA).chd"
   python3 tools/extract_retail.py "/path/to/Brave Fencer Musashi (USA).chd"
   python3 tools/extract_cd.py extracted/disc/files/MAIN.CD --output extracted/overlays/main
   

   These commands check your CHD against the pinned size and SHA-256 of the USA release. They write the BIN/CUE and the disc files to the ignored extracted/ directory.

4. Configure and build:

   cmake -S . -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo \
         -DMUSASHI_NATIVE_LANE=ON -DMUSASHI_LANE_OWN_CODE_ONLY=ON
   cmake --build build -j"$(nproc)"
   build/musashi_native_boot --disc extracted/disc/disc.cue
   

Full build instructions will be in BUILD.md (to be added). Also see docs/PC-PORT.md and docs/ARCHITECTURE-PORT.md. tools/package_legion.sh builds the release bundle with launch.sh, and runs the retail-data guard before it writes the tarball.

License

• The owner's original work in this repository is under the MIT License (LICENSE). That license covers only this work.
• The upstream decompilation Druthulu/BFM-decomp is credited as the reference this project was checked against. Its symbol and type names are used in config/, with credit. None of its code is included (see CREDITS.md).
• Third-party libraries and tools keep their own licenses (see CREDITS.md).
• Brave Fencer Musashi is © Square Enix (originally Square Co., Ltd.). This project is not affiliated with or endorsed by Square Enix or Sony Interactive Entertainment. See NOTICE.md.