Drew T
ce7780b91f
Item 1's remaining half. Oracle mechanized and reusable at tools/oracle/reg_renumber_swap.sh: break at reload entry (cc1 unstripped: reg_renumber @0x82d4330, reload @0x815d4d7), swap two hard regs across reg_renumber, finish the compile, re-score with masked_diff REUSED not reimplemented (R33). NEGATIVE CONTROL: a no-op swap (31<->31) reproduces exactly the baseline 13 mismatches, so the harness faithfully reproduces the pinned compile. RESULT: both contested swaps are far WORSE — <-> (17 pseudos) = 345 mismatches +1 insn; <-> (31 pseudos) = 97. Baseline 13. WHY, AND IT REFUTES THE FRAMING: reading .greg for cluster B's own insn shows (set (reg/v:SI 6 a2) (plus:SI (reg/v:SI 5 a1) (const_int 60))) — the destination is a HARD register, not a pseudo. reg_renumber only maps pseudos (>= FIRST_PSEUDO_REGISTER = 68), so that value is structurally unreachable by this oracle. The draft has NO register __asm__ pins (header says so, grep confirms), so is hard because it is an incoming PARAMETER register that local-alloc reused as a destination. VERDICT for func_80176734 (51,198 ins): the residual is NOT global-allocation 2-colouring. It is the LOCAL-alloc hard-reg reuse / tying class — combine_regs (2.7.2 local-alloc.c:1722) + qty_phys_copy_sugg, i.e. regalloc.md K8/RC-4, whose lever is C-level LIFETIME SHAPING, not the permuter and not reg_renumber. That also explains the flat permuter: it was mutating a dial that does not control this residual. MAP REFINEMENT OWED: §H presents the swap oracle as THE way to discriminate RC-6 from S3 in one gdb run. It has an unstated PRECONDITION — the contested registers must be held by PSEUDOS. Check .greg first; if they appear as (reg/v:SI N ...) with N < 68 they are already hard, and a coarse swap returns a large meaningless number (345 here) that looks like a verdict and is not one. Tree clean; nothing banked, nothing broken.
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.