Drew T
87b02b044f
THE BUG (real, found by a wave agent): jtbl_range() ends a carve at the next data dlabel, assuming every dlabel is an object boundary. spimdisasm can CUT ONE JUMP TABLE IN HALF and emit the tail under an invented D_ label — func_8012AAAC's 50-word table is jtbl_801D7FB0 (28) + D_801D8020 (22). The carve then reserves 112 B for an object supplying 200 B of .rodata, shifting every later symbol. §84-class: match_one is structurally blind; it surfaces only as a whole-binary DIFF. THE AGENT'S EVIDENCE WAS WRONG (R14): it reported D_801D8020 as having "ZERO xrefs anywhere in the tree" and proposed deleting the label. It has TWO (.word D_801D8020 and +0x2 in tail.data.s) — almost certainly spimdisasm mis-symbolizing packed halfword data, but "almost certainly" is not a gate, and the proposed remedy would have deleted a symbol two emitted words reference. I built the xref census first, watched it refuse, and only then found the references. THE GATE USED INSTEAD — the function's own `sltiu N` range check, which gcc emits right before the indexed load, so the PROGRAM declares its own table length (func_8012AAAC: sltiu 0x32 = 50). Absorb only when the next label is immediately adjacent, its words are all code addresses in the overlay's text, and absorbing lands on an EXACT sltiu bound (the SET, not max() — a multi-switch function has several and no way to say which owns this table). Three further corrections, each caught by testing rather than assumed: - the absorption fired and the trailing-pad trim immediately UNDID it (re-trimming against the first dlabel's 28 words); the trim now sees the whole absorbed table; - a continuation ends at ITS OWN last .word, not the next dlabel (D_801D8020 ends 0x801D8078; the next dlabel is 0x801D8158, 224 B on) — using the next dlabel is the assumption being repaired; - the shortfall warning now fires only on an unambiguous single-bound pairing (it fired ~90 times across 38 tables before the guard — a warning that fires on ambiguity is noise, not a signal). VERIFIED: the split table 28 -> 50 words (112 -> 200 B), matching the agent's 3 independent confirmations; and across 38 jtbls x 6 functions = 228 combinations, EXACTLY ONE range changes — that table, for its owning function only.
BFM-decomp
A matching decompilation of Brave Fencer Musashi (PlayStation, SLUS-00726, USA 1998) — the first public decompilation effort for this game.
What "matching" means
The goal is C source code that, compiled with the original-era toolchain (PsyQ 4.x / GCC 2.7.2-family + ASPSX via maspsx), produces a byte-for-byte identical SLUS_007.26 and, eventually, byte-identical overlay binaries. SHA1 checksums are the ground truth; "functionally equivalent" does not count.
No ROM content
This repository contains no game assets, no disassembly output, and no ROM-derived data — only source code, build configuration, symbol names/addresses, hashes, and documentation. To build or contribute you must provide your own dump of the game disc (4-track BIN/CUE, redump layout). See .gitignore for the firewall.
Project status
Latest (Phase 19, 2026-06-20): the project builds 136 binaries byte-identical from a clean tree (the EXE + the resident engine + all 134 location overlays);
make check-all→ 136/136. Fleet byte-identical-from-source is 58.0% (function-instance-weighted; see the PhaseEnds for the byte-weighted ~30% figure and what it includes). Shared engine functions are matched once inov_SC01_077and propagated ×134 viatools/dedup_propagate.py. (The narrative below is Phase-11/12-era; a full refresh is part of the public-flip prep.)
Gen1 (foundation) complete — the matching pipeline is proven end-to-end. make extract && make build && make check rebuilds SLUS_007.26 byte-for-byte identical (SHA1 143dbb89…) from C + assembly, reproducibly across many sessions.
- Compiler pinned by evidence:
gcc-2.7.2-psx -O2 -G0 -mips1 -mcpu=3000+maspsx --aspsx-version=2.56 --expand-div. - 52 functions hand-matched to byte-identical machine code — including the LZSS streaming decompressor — with a decomp-permuter + matching-cookbook "flywheel" to accelerate the next.
- 959 PsyQ SDK functions linked byte-identical (libcd, libgs, libgte, libspu/libsnd, libgpu, libc2, libmcrd, libapi/libcard, libetc) straight from the real PsyQ 4.0 libraries instead of re-decompiling them — bringing byte-identical-from-source coverage of the EXE to ~50%.
- File-loader / overlay system reverse-engineered, with the resident engine blob + location overlays' load addresses proven byte-identical against a live PCSX-Redux RAM dump.
About half the EXE is still INCLUDE_ASM stubs (correct bytes, not yet C), and the bulk of the game lives in compressed overlays inside the .CD archives — Gen2 (overlays & engine at scale) is underway:
- The build toolchain is binary-agnostic (one parameterized pipeline builds any binary), and the always-resident engine blob rebuilds byte-for-byte from source (SHA1
8e17e02f…) — the second binary reconstructed exactly, after the EXE — and is now 86% hand-matched C (123 / 146 functions, up from 0): its scripting turned out to be compiled-MIPS state/mode dispatch, not a bytecode VM, and the save-file + sound (SQV) formats are documented. The harvest used a reusable swarm-of-agents + bit-for-bit byte-gate method (a wrong match can't be accepted) —tools/harvest_verify.py+tools/match_one.py, which carry straight into the overlay phase. - A cross-binary deduplication pipeline is live: a Ghidra-free signer fingerprints all 134 location overlays, and the report finds ~9,000 byte-identical function groups shared across binaries (~28 MB of collapsible code) — a single engine function is byte-identical in all 134 overlays. This is "one match unlocks many": each engine match will be auto-credited across the overlay fleet.
Current phase and detailed progress live in phase-ends/ (newest PhaseEnd_*.md = current state); methodology, rules, and the full roadmap are in PROJECT_CONTEXT.md; environment setup in docs/SETUP.md.
This project is developed primarily by Claude Code driving Ghidra through an MCP server; see CLAUDE.md.
License
Private repository for now. AGPL-3.0 is planned at public release, modeled on sotn-decomp. tools/brave-CUE/ is CUE's BRAVE extractor (GPL, source included) and retains its own license.