goldeneye-pc-port/AGENTS.md

# AGENTS.md — GoldenEye 007 PC Port

## What this is

- `n64decomp/007`: WIP decompilation of GoldenEye 007 (N64), byte-matches US/EU/JP ROMs.
- Active work: **PC port** modelled on the Perfect Dark PC port (same Rare "Indy" engine family).
- **Read `docs/PCPortResearch.md` first** — architecture, GE-specific RSP deltas, phased plan, and review findings (A1–D33 in §11; current handoff + plan in §H).
- **Starting a fresh session?** Read `docs/HANDOFF.md` — the paste-ready brief with the immediate task, standing procedure, and environment gotchas.

## Non-negotiables

1. **N64 build untouched.** `Makefile`, `tools/`, `rsp/`, `ld/` belong to the N64 build. Never modify them for the PC port.
2. **Game logic is unmodified.** The decomp's control flow and behavior are ground truth for 1:1 fidelity — never change them. All N64 *hardware* dependencies are satisfied by the `port/` layer; if a game file seems to need a behavioral change, stop — the fix belongs in `port/`. **Narrow exception (ABI/layout only):** the 32→64-bit transition forces a small class of mechanical, semantics-preserving edits that cannot be isolated in `port/` — chiefly pointer-width reconciliation in ROM-serialized structs (a struct with a 32-bit-pointer field misaligns when read as 64-bit). These follow the PD ground-truth pattern (store the embedded address as `u32`, cast to a real pointer at the use site), change no logic or behavior, and are each documented in `docs/PCPortResearch.md` §F/D3x. No other game-code edits are permitted.
3. **Region macros mirror the Makefile.** `CMakeLists.txt` `REGION_DEFS` must match the N64 Makefile's per-region macro set exactly (finding A1). Divergence = silent branch divergence + link failures.
4. **`src/libultrare/Makefile.libultrare` is ground truth** for original-vs-Rare libultra files (finding B3). The PC build compiles: `libultra/audio`, `libultrare/audio` (drvrNew/env/reverb), `libultra/gu`, and `libultrare/io/vitbl.c` only. All other `io/` + `os/` files are excluded and shimmed in `port/src/libultra.c`.
5. **`rsp/graphics/gmain.s` is the RSP ground truth** — the authoritative reference for which GBI commands GE emits (modified fast3d, 1545 lines). We do not run it on PC; `port/fast3d/` replaces it. Use it to validate the software RSP's command decoding and the custom CC/RM modes.

## Critical files

| File | Role |
|---|---|
| `docs/PCPortResearch.md` | Research + plan + findings (A1–C2). Read first. |
| `CMakeLists.txt` | PC build (parallel to the N64 Makefile). Source list + `REGION_DEFS` live here. |
| `port/src/` | Shims: `libultra.c` (OS API), `gesched.c` (scheduler), `n64stubs.c` (boot/TLB/FPU/rmon), `random.c` (PRNG ported verbatim from `random.s`), `ucode.c` (microcode segment markers), `main.c`, `video.c`, … |
| `port/fast3d/` | Software RSP (adapted from the PD port). The main Phase 2 work. |
| `rsp/graphics/gmain.s` | GE's RSP ucode — ground truth for GBI/CC/RM. |
| `PD_PORT_CHECKOUT` | Perfect Dark PC port checkout — **standing reference for this project**: consult it whenever a remaining work item has a PD analogue (same Rare engine family). Port-layer ground truth (`port/fast3d/`, crash/system/video), plus copy candidates: `port/src/preprocess/` (N64→PC asset conversion at load; `filemodel.c` is the D43 near-analogue, same vma 0x5000000) and `mixer.c`/`input.c`/`fs.c` (Phase 3/4 — our stubs were scaffolded to be replaced by these). Caveats: port-layer files only; same family ≠ identical format — validate per field. Full audit: `docs/PCPortResearch.md` §2.4. |

## Build

```sh
./build-pc.sh ntsc-final   # or pal-final / jpn-final
```

Needs CMake + SDL2 + zlib + OpenGL (MSYS2 packages: see `build-pc.sh` header). ROM goes in `./data/` (not distributed).

## Verification ritual (after any build-affecting change)

1. **Undefined symbols.** Every symbol referenced by the compiled set (see `CMakeLists.txt`: `SRC_GAME`, `SRC_ENGINE`, `SRC_LIBAUDIO`, `SRC_LIBULTRARE_AUDIO`, `SRC_LIBULTRARE_DATA`, `SRC_GU`, `SRC_PORT*`) must be defined exactly once in the compiled set or in `port/`. Symbols that live in EXCLUDED files (`libultra/io/*`, `libultrare/io/*` except `vitbl.c`, `libultra/os/*`, `libultrare/os/*`, `sched.c`, `rmon.c`, `vi.c`, `src/*.s`) must be provided by `port/src/libultra.c`, `gesched.c`, `n64stubs.c`, `random.c`, or `ucode.c`.
2. **Duplicates.** No symbol defined twice across the compiled set (watch `sp_*` stacks, `rmon*`, `os*` shims, segment markers).
3. **Syntax.** Every touched file must parse; once the toolchain is installed, `./build-pc.sh` is the final word.

Run `/linkcheck` for this sweep. Record new findings in `docs/PCPortResearch.md` §11 style (next label after the last used).

## Phase status

- **Phase 0 (scaffolding):** done, committed.
- **Compile+link milestone:** all ~235 TUs compile and `ge007.x86_64.exe` links clean (`ninja ge007 -k 0`, 236/236). Findings D7–D17 in `docs/PCPortResearch.md` §11; asset stubs in `port/src/assetstubs.c`, fast3d no-ops in `port/src/gfxstub.c` (delete when real fast3d lands).
- **Phase 1 (boot to window):** done — ROM loads/validates/maps at cart base 0x10000000 (`romdata.c`), SDL2 window + GL clear loop (`video.c`), absolute asset symbols from `scripts/gen_romassets.py` → `port/src/romassets_<r>.s` (findings D18–D23).
- **Phase 1.5 (boot to first frame):** DONE — boot chain complete AND real frames render (`[NOTE] frame N rendered in … us`). D34–D42 closed the blockers on top of D31–D33: ANIM_DATA lvalues, music seq-table ABI+endianness, music-heap sizing, libaudio bank-tree re-layout, implicit-declaration prototype shim (D38), Globalimagetable rebasing + true segment size (D39), ModelHitEntry pool sizing (D40), cross-thread GL context release (D41), rsp task-settings toggle (D42). ROM dump verified against the No-Intro good dump (byte-identical, header CRCs re-checked — `tools_pc/romverify.c`).
- **Phase 2 (rendering):** IN PROGRESS — fast3d integrated + real frames render. **Plan B EXECUTED (D50, committed):** all 512 NTSC model files converted offline by `tools_pc/d43_emit.py` → `data/pcmodels-ntsc-final/pcmodels.bin` + manifest.csv (single concatenated RZ image; regenerate per region with the script — sidecars are gitignored), served through the existing load path via a port-layer table patch (`port/src/pcmodels.c`, romdata cart-extension, one-shot `pcmodelsPatchTable()` + poolRemaining reset hook in `load_object_fill_header`); runtime C fixups for language-bank BE offset tables + font re-layout (D50.3/D50.4); legal-screen UB seed (D50.5); **D50.6 fixed the first model-render crash** — `texCopyGdls` copied only w0 of each 16-byte Gfx slot on PC (the union's trailing `long long` is 8 bytes), leaving stale mempool w1s in the compacted GDLs; byte-proven against PlegalpageZ, fixed with a full-slot copy under #ifdef PORT. Model GDLs now execute to completion (PlegalpageZ sub-DLs). **D51 RESOLVED** (font `pixeldata` fixup wrote the pointer at the wrong offsets — frame-5 `import_texture_i8` crash gone; GE opcode space decoded along the way, G_TEXRECT=0xE4/0xE5 non-F3DEX numbering), **D52 RESOLVED** (`osGetCount` now advances at the N64 RSP counter rate ≈ 46.5525 ticks/µs — fixed the non-deterministic post-frame-2 hang), **D53 RESOLVED** (model RW-data pool addressing: D53.1 `Model.datas` word-stride → `u32 *` under PORT + casts; D53.2 ModelSlot/AnimModelSlot re-laid on top of the PC struct Model — in-use@0x10 / pool@0x20, slot size = sizeof(Model) = 0xE8 — plus PORT-guarded heap-fallback bumps in model.c), **D54 RESOLVED** (cseq ALCMidiHdr BE header: port-layer `romdataFixupCseq` bswap32 of the first 17 u32s, called from music.c after each decompress), **D54b RESOLVED** (synth param slots sized for ALStartParamAlt = 0x28 in synthesizer.c alSynInit under PORT), **D55 RESOLVED** (RLE folder-menu background BE w/h header: bswap32 of the first word at `(u32 *)&unknown2` at cart-map time in romdataInit, guarded). Build GREEN; game boots, plays intro music, renders through logo/gun-barrel, instantiates Brosnan, and executes the gun-barrel hole DL clean to ENDDL. **D56 RESOLVED** (watch Model/RW-pool raw offsets: field-name Model access + static 0xC8-byte pool under PORT in bondview2.c), **D57 RESOLVED** (pointer-grown rwdata records overflowed N64-sized spare pools — Brosnan PC numRecords 153 > 140: capacities grown in initunk_005520.c + dynamic slot+pool fallback in model.c), **D58 RESOLVED** (gun-barrel DL: vertex-pointer K0 idiom rebuilt via `OS_K0_TO_PHYSICAL(…) | 0x80000000` in title.c + DL reserve 0x100→0x200 because `sizeof(Gfx)` is 16 on PC). **D59–D68 RESOLVED (committed):** the "GL DLL" crash was D64's unbounded blood-RLE write (sentinel section-adjacency lost on PC) clobbering the gun-barrel sub-DL; then D60–D62 (DMA target validation, OSMesgQueue layout), D65/D65b (HEADS/BODIES enum signed sentinels under PORT), D66 (romCopyAligned + ramrom replay 64-bit pointer width), D67 (struct image_entry N64 layout), **D68 (Globalimagetable BE→LE fixup** — `port/src/gimgfixup.c` bswaps IMAGESEG Gfx w1 words + sImageTableEntry.index after texReset's romCopy; compiled globalDL shadows synced for explosion.c). The game now renders the **entire intro** (logo → gun barrel w/ Brosnan → cast; ~frame 2100, ≈2 min wall-clock at the current ~20 fps clean-run rate). **D69 RESOLVED (committed):** `load_bg_file` no longer faults on stage load. BG-file headers/records are N64 big-endian segment-0x0F offsets with internal self-relative offsets; fixed via offline sidecar conversion (`tools_pc/d69_emit.py` → `data/pccg-<region>/pccg.bin` + manifest, same Plan-B pattern as D43/pcmodels, port-layer wiring in `port/src/pccg.c`) plus four ABI layout fixes surfaced along the way: D78 (`StandTile` id/room bitfield packing), D79 (`bg_room_data` pointer-width), D83 (`StandTileHeaderMid`/`Tail` bitfield packing — same class as D78, caused an infinite loop in `stanBuildRoomData` until fixed), D84 (hand-inlined `BG_SEG_TO_PTR`-style folds in room-DL loaders needed the same `(u32)`-cast 32-bit wrap the macro already has). **D85 OPEN, D86/D87 RESOLVED, D88 OPEN (current blocker) — found during/after D69 verification:** D85 — room primary/secondary DL binaries decompress correctly but `texLoadFromGdl` (the already-working model-GDL runtime converter) produces garbage from their content, not yet root-caused; safety-netted (bounds-checked in `bgBuildRoomVtxBounds` so it can't segfault, but geometry is wrong/empty). D86 (RESOLVED) — `modelInitRwData` crash was a single `(int)`-truncated pointer in `initplayergaitobject.c`'s embedded player gait-model init; fixed under `#ifdef PORT`. D87 (RESOLVED) — the front end's genuine attract-mode demo playback crashed on an unswapped big-endian `ramromfilestructure`; fixed with a `#ifdef PORT` byteswap fixup in `ramromreplay.c` (D54-cseq pattern). D88.1–D88.3 (DONE, VERIFIED, uncommitted) — the per-level `Usetup*Z` "stage setup" file (`prop.c`/`struct stagesetup`) is now converted offline by `tools_pc/d88_emit.py` (531 lines; delta-relocates the 8 pointer-widened sub-tables + bswaps s32 ID/offset fields, appended to the same sidecar image; `PCCG_MAX_FILES` 128→256), plus a `SetupIntroCamera` narrow-`u32` `#ifdef PORT` ABI fix (D79/D53.1 class, write-before-read verified). `-level_09` + `GE_D88=1` confirms `proplvreset2` now walks the full pads table correctly; the `prop.c:1306` crash is gone. D88.4 (OPEN, current blocker) — `d88_emit.py` deliberately leaves the `propDefs` polymorphic record stream un-byteswapped; `-level_09` now crashes in `setupDoor` (`prop.c:971`) → `modelLoad` on a garbage big-endian `door->obj`. Needs a per-type byteswap + struct-size audit of the ~40 prop-def record types. See `docs/HANDOFF.md` and `docs/PCPortResearch.md` §F/D88.1-D88.5 for full detail and next steps. **D70–D74 (intro-logo pixels, RESOLVED):** D70 env-gated PPM frame capture (`GE_PCDUMP` → `./ppm/`, gitignored — kept as permanent dev tooling); **D71** C-array texture sources (the four rarewarelogo.c RGBA16 images) byte-swapped on LE PC → port-layer per-source bswap in `import_texture`; **D72** the UV path (GE always uses authored `tc[]` UVs; `lookat_enabled` defaults false); **D73 = root cause of old D72.3** — sinf/cosf `du` double constants are big-endian word pairs, garbage on LE PC → guMtxF2L emitted −32768 for every sin/cos entry → logo triangles projected off-screen; fixed with the PORT-only `DVAL()` macro in `src/libultra/gu/guint.h` (sinf.c/cosf.c `.d` reads replaced; N64 build untouched); **D74** texture import fallback no longer truncates valid gDPLoadBlock data (was dropping letter mip chains + reducing D_02005FF0 to 32×3), `TextureCacheKey` gained `size_bytes`, and the VBO path wraps UVs by tile size for WRAP sub-tiles (N64 semantics). The Rareware logo now renders its four gold letters on the dark-blue plate (PPM-verified ~frame 555; final pixel-perfect check vs N64 footage optional). D69 is resolved; D88.4 is the current crash blocker to a rendered stage frame, with D85 (room geometry) and D75 (front-end 3D model rendering — Nintendo logo mispositioned, gun-barrel Bond model absent, cast-roll character models absent) next after it (see above / §F). Committed through D87. Recurring sub-task: ABI/layout fixes per the D32 procedure (§H) as more asset types are first touched (PD's `preprocess/` module already solves most of them; prefer the offline pattern for format work — D48; full-struct Gfx copies on PC — D50.6; audit struct type-puns after pointer-width changes — D53.2; raw byte offsets into pointer-containing structs shift on PC — D56; N64-sized reservations must be re-checked against 16-byte Gfx/Vtx widths — D58). **Open this session (tracked in §F as D75–D77, lower priority than D69):** D75 3D rendering still wrong (Nintendo logo misplacement + intro player models absent); D76 2D disclaimer screen only partially drawn; D77 no audible music on PC. Prioritization: rendering over audio unless a shared root cause is found (Q1).
- **Phase 3 (audio + input):** libaudio → SDL — largely copy-and-adapt from PD (`mixer.c` 722 lines vs our 31-line stub; `input.c` SDL_GameController backend; §2.4); decide the ASP strategy (C2: `aspMain*` dummies in `ucode.c`).
- **Phase 4 (saves + polish):** file-backed EEPROM — build on PD's `fs.c` (file-backed save dir); PFS/motor already no-op stubs.