Drew T
5e10215269
md_MAIN_011:func_800CF28C · md_MAIN_003:func_800D0268/func_800D0740/func_800D0C50, all byte-verified
from a clean rebuild and counted from the SOURCE: md_MAIN_011 is now FULLY MATCHED (0 open stubs),
md_MAIN_003 is down to 1 (func_800CF3E8).
THE PREMISE I HANDED THE AGENT WAS WRONG, AND IT SAID SO. md_MAIN_011 is already a whole-object -O0
module — no carve was needed. Its real blocker was tools/jtbl_rodata_pads._s_rodata_span ignoring a
trailing `.align`, the SAME defect this session fixed for md_SC07_003 from the other direction: two
agents converged on it independently. Adopted this agent's stricter form (only a TRULY trailing
align rounds `hi`; an interior one is followed by data that sets `hi` higher anyway).
Note WHY it stayed latent: `derive`'s zero_gap self-corrects a 1-3 byte undershoot whenever the next
stream item is an anchor. A C jump table has NO anchor — so the bug can only fire the moment someone
banks a switch function into such an object, and when it fires it accuses the CARVE ("island layout
drift"), not itself.
md_MAIN_003 needed one new -O0 object, and the boundary I proposed (0x1f74 -> 0x1e58) was both too
narrow and off by 0x2B8. The carve made is `md_MAIN_003_o0e` at 0x1308 (vram 0x800D0100) running to
the existing o0c boundary: everything in that span is a §265 verbatim __asm__ body or an INCLUDE_ASM
stub — zero optimizable C — so the whole tail flips with one cut. Proved byte-identical with NOTHING
banked first (§431 discipline), then the three drafts gated one at a time.
TWO MORE GENERAL DEFECTS FIXED IN jr_isolate_all, both of which silently mis-place a boundary:
* an item-less CLOSING region emitted a duplicate `- [off, c, …]` line and the validator refused;
the empty-region skip covered only region 0, and `_partition`'s empty `footer` made the closing
region look non-empty.
* A §265 VERBATIM __asm__ BODY IS PREAMBLE, AND PREAMBLE IS ASSUMED BYTE-NEUTRAL. It is not — it
emits bytes. `parse_overlay_c` has four addressed-anchor forms and a verbatim body is none of
them, so it attaches to the NEXT anchor: cutting at func_800D0268 would have moved 0x168 bytes of
other functions into the new object while the yaml claimed the region starts higher. New
`_region_emit_start()` derives the yaml offset from the region's CONTENT (item addresses + every
.globl/.ent the text names that resolves inside the object) and takes min(cut, emit), so a
boundary can only move DOWN. Where no verbatim asm is in play it equals the cut — every existing
isolate is unchanged.
BLAST RADIUS PROVEN, not argued: jtbl_rodata_pads is in the build path (`--derive` for md_*/main),
so the agent rebuilt main + all 70 md_* from scratch (71/71) and then ran the full fleet:
**make check-all 213/213 passed, 0 failed**, main 143dbb89 BYTE-IDENTICAL.
CENSUS, denominator asserted (1057 live stubs, 0 without a .s): exactly ONE -O0-prologue stub
remains stranded in an -O2 TU fleet-wide — main:func_8002C410 in src/800_b.c, 299 ins. Nothing more
should be built for this class; the general tool already existed and what was missing was
correctness, not coverage.
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.