Drew T
d2b48b7680
Promotes the proven probe (commit:1266) into a real tool, and validates it FIRST-TRY on a
fresh overlay.
tools/o0_subsplit.py <ov> --lo <vram> --hi <vram>:
- derives the range's contents from the SOURCE ANCHORS (overlay_src_split.parse_overlay_c:
`asm` = unmatched stub, `define`/`def`/`nonmatch` = already matched), NEVER from an asm
scan -- a matched fn emits no .s, which is exactly the blindness that made the range look
like a clean contiguous run (SS126 / SS124's shape);
- computes the -O0 bound as (address range MINUS already-matched bodies) and emits ONE
sub-region per maximal run of unmatched anchors (K matched islands => K+1 regions);
- names each `<ov>_o0<letter>` picking free suffixes, so the widened Makefile glob selects
them; refuses loudly if it runs out or if the range spans >1 object or is already -O0;
- honours the one-carve-per-region law (forces a cut at every already-banked jr in the
object) and reuses jr_isolate_all's plan/build_new_config/ascending-unique validation
verbatim, so carve-repoint + source-repartition stay on the proven path;
- warns (does not refuse) when a stub in an -O0 run lacks the frame-pointer prologue --
the byte-gate is the arbiter, not the heuristic.
VALIDATION on ov_SC03_015 (untouched by the manual probe): the tool independently derived the
SAME structure found by hand on ov_SC03_014 -- 2 matched -O2 islands (func_80184440,
func_801848E4), 2 -O0 regions (8 + 7 fns), same 5 cuts. Sub-split -> BYTE-IDENTICAL. Then 3
drafts, each global DERIVED FROM THAT OVERLAY'S OWN ASM (%hi operand) rather than copied:
3/3 match_one --o0 MATCH (22 ins), 3/3 through the whole-binary gate.
BANKED this commit: func_801846E4 / func_8018473C / func_80184794 in ov_SC03_015 (6 across
the two overlays now). The other 24 stubs in the region are undrafted -- the route makes them
DRAFTABLE (they were un-bankable at any effort before); drafting them is crack-wave work.
R22 CLEAN-FLEET: extract-all 139/139 (+main); check-all 140 passed, 0 failed of 140.
cookbook SS126 (the address-range-is-not-an-optimization-region law + the probe ladder).
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.