ReaperOfVeriod
282e633a7c
Last commit claimed exactly one GP-relative occurrence of the collision assert
string's $lo half, at 0x354cc8, and called it an unambiguous anchor. That was
wrong, and building the disassembler is what proved it.
The search compared word bytes 1..3 against the 16-bit immediate. The PS2's MIPS
is little-endian, so an I-type immediate sits in bits 15..0 -- word bytes 0 and
1. Bytes 1..3 are the opcode, $rs and $rt fields. The match was on those.
The instruction at the phantom hit is 0x24a89948:
addiu $t0, $a1, -0x66b8
whose real immediate is 0x9948 -- ten bytes from the 0x99a8 being searched for.
-0x66b8 merely looks like a plausible $gp offset, which is what made it
convincing. With the byte order corrected the count is ZERO, in 2,751,268 bytes.
So the anchor is not established and the assertion is withdrawn. What survives is
still worth having: the functions are named (Camera_CollPrimTest takes (prim,
grid)), $gp = 0x1AEFF0, .lit loads at 0x1A7C80, and the assert string is a unique
copy at overlay+0xd18.
Probably the code reaching that string does not address it through $gp, or
reaches a copy in another section. The decomp's assert-message-names.tsv gives
0x002db350 for level 0 -- inside .lit, but it disassembles to a function epilogue
(jr $ra / addiu $sp, $sp, 0x70), so those are code locations, not string
addresses, and they are not traced to the assert either.
tools/overlay-anchors now does the search with the correct byte order and
carries a comment on exactly the part that was wrong, because that is the part
that will be re-derived otherwise. It also disassembles around an address:
cargo run -q -p gc-overlay-anchors -- <overlay.bin> --disasm 0x2db350 0 64
The useful general lesson, which the roadmap already says and this is a second
demonstration of: a probe that returns a small, clean, narratively satisfying
number is the most dangerous kind of wrong result. "Exactly one hit in 2.75 MB"
read as conclusive. It was an artifact of comparing the wrong two bytes, and it
survived a commit because it fit the story.
Going Commando
A native PC reimplementation of Ratchet & Clank: Going Commando (PlayStation 2, 2003), written in Rust.
The game is reimplemented, not emulated. There is no MIPS interpreter here and no CPU emulator: the systems are ported to Rust so they run as ordinary native code.
Status: initial scaffold. The disc is identified and verified, the
workspace builds, and nothing else is implemented yet. See
docs/roadmap.md for where things stand and what comes next.
The target
| Game | Ratchet & Clank: Going Commando |
| Platform | PlayStation 2 |
| Disc | SCUS_972.68 v1.01, USA Black Label |
| Video | NTSC, 60 Hz |
| Boot ELF SHA-1 | bacda860cbd6723142e86db56f197e47e728970f |
Verified against a real disc — see docs/disc-identification.md.
This is the build the reference projects pin; Greatest Hits v2.00 is a
different binary and is not the target.
No game content
This repository contains no game assets, no disc images, no BIOS dumps and no proprietary toolchains. You supply your own legally obtained copy of the disc as an input, the way the upstream reference projects do.
A pre-commit hook enforces this, blocking disc images, asset directories, container signatures and files over 50 MiB. If you clone elsewhere, enable it:
git config core.hooksPath .githooks
Layout
crates/
gc-formats/ asset format parsers (pure, no I/O beyond the caller's buffer)
gc-extract/ disc pipeline: identify, unpack, verify
gc-game/ game logic: hero, weapons, moby classes, progression, saves
gc-video/ IPU / MPEG-2 decode
gc-engine/ Bevy app: Graphics Synthesizer, VU0/VU1, renderer, frame loop
docs/
disc-identification.md which disc we build against, verified
roadmap.md phases, gates, current status
plan/ one file per subsystem, written as work proceeds
formats/ format specs, written as formats are reversed
tools/
identify-disc.py identify any Going Commando disc image
vendor/
rerac/ pinned upstream reference checkout (not tracked)
Building
Requires a Rust toolchain via rustup.
cargo check --workspace
cargo test --workspace
The host audio backend is disabled in Cargo.toml (see the comment there) so
that the workspace builds without system ALSA development headers. Audio decode
is the last phase of the port and lives in gc-video; re-enable it and install
alsa-lib-devel when that work starts.
Identifying a disc
python3 tools/identify-disc.py <your-disc.iso>
Reports the serial, version and video mode from SYSTEM.CNF, hashes the boot
executable, and warns when the disc is not the supported build. Reads only a
few megabytes, so it is near-instant.
How it will be verified
Visual and behavioural comparison against PCSX2, replaying recorded input and
comparing frames, level by level. The PS2 float model is reproduced rather than
approximated — see AGENTS.md.
PCSX2 is installed and working on this machine; the comparison loop that reads
the game's own memory over its debug protocol is up, and level 0's and level
1's tfrag lighting are verified byte-exact against it. See
docs/plan/pcsx2-verification.md for the
setup and how to run it.
Credits and licensing
This project learns from and is built on the work of others. Licences are
recorded in PROVENANCE.md and notices must travel with any
code derived from them.
- ReRAC — a native Rust/Bevy port of Ratchet & Clank (2002), the first game. ISC. The architecture this project follows.
- OpenRAC / rac2-gc-decomp — matching decompilation research for this game. MIT. Source of verified struct layouts and engine documentation.
- Wrench — community documentation of Insomniac's container formats. GPL, used as a specification reference only; no code is copied.
Ratchet & Clank is a trademark of Sony Interactive Entertainment. This is an unofficial fan project, not affiliated with or endorsed by Sony Interactive Entertainment or Insomniac Games.