Drew T
a6f6ccf545
Seven sweeps moved distinct-code by +125/+125/+129 and +0 four times; I had logged it four times as
"unexplained, still not guessed at". Modelled in one pass:
delta_distinct = (distinct h_exact classes in the family) - (classes already matched)
weighted_metrics counts distinct h_exact classes with >=1 matched instance. EXACT on all 7, no
residual: func_80135260 131-6=125; func_80133AB0 131-6=125; func_80156044 130-1=129; the four +0
families have EXACTLY 1 class across all 138 overlays (every member byte-identical), already matched
via the exemplar.
IT IS A REAL SIGNAL, NOT NOISE. A byte-IDENTICAL family is ONE piece of distinct code — the
exemplar's crack already reconstructed it, so the other 137 banks pay fleet/instr in full (each
binary now builds from source instead of pasted asm) but add NO new reverse-engineering. A
byte-VARIANT family is ~130 genuinely different functions and pays both. The two headline metrics
rank the same work differently, and both are now predictable BEFORE spending a sweep.
THE REMAINING FRONTIER, PRICED BOTH WAYS (49 eligible non-jr families):
byte-identical 13 families 80,085 ins 0 distinct
byte-variant 36 families 114,331 ins 2,962 distinct
total 49 194,416 ins (~1.48 pp instr)
MY OWN BUG, CAUGHT BY VERIFYING (R14): my first ranking reported ALL 49 families as byte-identical /
0 distinct yield. Defect in my probe — I wrote int(x,16) on the member address in one comprehension
and forgot it in the next, so every sig lookup missed and every family collapsed to one class. Caught
only by spot-checking two entries against a direct count (func_80143D28 is 130 classes, not 1). Had I
reported it, the conclusion "the entire remaining harvest is worthless for distinct-code" would have
been exactly backwards for 36 of 49 families.
cookbook §111, with §106 applied: the ranking is two lines over the sigs, so it is derivable on
demand and deliberately NOT committed as a table that rots.
No src/ or config/ change: no bank, no metric move.
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.