Drew T
fa51d30d3e
- CRACKED by an Opus 5 agent @ xHigh and VERIFIED INDEPENDENTLY: match_one -> MATCH (1194 ins),
100% every region, 1129 -> 1069 -> 37 -> 28 -> MATCH. It is the matched base func_8017CA80
(952) + two deltas: a 14-ins grey-colour prologue from D_801DCCA0, and a FIFTH switch arm
(case 2 / case 3 split, proved against the real jump table) emitting a POLY_FT4 plus a 7-word
subtractive overlay.
- NOT BANKED. The whole-binary gate said DIFF and it is RIGHT: this is a jr (jump-table) function
(jr $v0 at .s:409; table jtbl_801DB70C in asm/ov_SC06_029/data/tail21.data.s). Matching the C
makes gcc emit that jtbl into .rodata while the raw copy stays in the data tail -> duplicate +
wrong address. match_one masks jal/HI16/LO16 so it CANNOT see this -- the §53 carve law.
- THE CHAIN, each step failing LOUD with its own remedy (the tooling behaved well, R32/R35):
(1) harvest_verify -> DIFF, not PLUMBING.
(2) jtbl_carve --func func_8017C954 -> refuses: subseg ov_SC06_029_jr_8017AE2C would host
NON-CONTIGUOUS .rodata carves (0xb3468, 0xb35b4); one object can't leave a gap for the
unmatched jtbl between them. Remedy: isolate into its own code subseg first.
(3) jr_isolate_all --dry-run (47 jr / 21 objects) -> REFUSES: 2 file-scope decls
(extern struct PW8017E6D8 D_801E1EC4/EC8) could not be placed, and it will not emit a region
that silently omits them ("a dropped prototype is a SILENT BYTE-CHANGER" -- C89 implicit
int f(), and return type drives delay-slot fill here). NB struct PW8017E6D8 IS already in
engine_types.h:658, so this looks like a placement-logic gap, not a missing type -- that is
the precise next thing to check.
- => banking is a bounded BUILD-INFRA task (T2 config resegment => full R22), not more matching.
Deliberately not started this deep into the session. Match + harness preserved and tracked.
- AGENT FINDINGS: §80(i) confirmed twice more (x_e1swap measured exactly neutral then later paid
-2; the za lever measured worse and became necessary two levers on). NEW DIAGNOSTIC: when a
residual is "a whole block of registers renamed by ONE SLOT", read the .greg `;; N conflicts:`
AND `;; N preferences:` lines for the block's top allocno -- a missing hard-reg conflict plus a
new copy preference is the signature of a one-slot slide, one dial away not forty bugs
(c954_reg.py, the per-region scorer, is the reusable tool).
- HONEST CAVEAT (the agent's own): its lever 1 is a hand-placed byte-free __asm__ register-clobber
dial, not a construct the original author would have typed; 14 natural spellings were tried and
measured. Bytes unaffected, true source shape unfound; the report names the next probe.
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.