Claude (auto-RE)
398e8ae0af
The whole retail save is 545 bytes: a GDHA container wrapping a zlib payload,
which is a chunk stream — 'GDAA', a length-prefixed game-phase name (GP_BUNK,
one of the title's GP_* screen ids), a 'GHAD' 122-byte progress block, a
count-prefixed table of 16 20-byte save slots, and a trailer.
None of it is guessed. The layout comes from the serializer at 0x822C00E8 and
its callee 0x822BF678: the writer primitive is 0x821885A8(stream, buf, len), the
slot count 16 and the 20-byte stride are literals, and the GHAD block is ten u32,
a u64, four u32, a raw 4-byte field and a raw 54-byte blob = 122 bytes, which is
exactly what the file carries. savegame.py re-serializes the parse and asserts
byte-identity.
Because the struct is written field-by-field with no packing changes, a payload
offset is also the offset in the live save object -- save+8 for GHAD, save+136
for the slot table, and 136+16*20 = 456 is the serializer's very next access.
Confirmed independently: slot 0's trailing two u32 decode as a FILETIME to
2026-07-23 20:07:23 UTC, and the content header's display string (written by the
game) says 07/23/2026 21:08 at UTC+1; the 15 empty slots hold 2006-01-01 rather
than zero.
Field meanings are left ❔ on purpose -- the naming oracle is a diff of two
saves, and all four copies on disk are byte-identical, so a second save has to
be made first. Nothing has been written back to any save.
47 lines
8.6 KiB
Markdown
47 lines
8.6 KiB
Markdown
# RE knowledge index
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Confidence: ✅ `CONFIRMED` · 🟡 `PROBABLE` · ❔ `HYPOTHESIS`. See [README](README.md).
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Formats we've already reversed are, for now, **documented by their parser + disc round-trip
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tests** (the executable spec) rather than a prose file — the "Spec" column points there.
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Promote to a prose `structures/…md` file when a format needs behavioural notes beyond layout.
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## Data structures / formats
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| Format | Conf. | Spec (parser + tests) | Notes |
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|--------|-------|-----------------------|-------|
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| IPFB `.pak` archive | ✅ | `sylpheed-formats/src/pak.rs` + `tests/pak_idxd_disc.rs` | header + 12-byte TOC, Z1/zlib payloads |
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| name-hash (TOC keys) | ✅ | `sylpheed-formats/src/hash.rs` | Barrett-reduction hash; recovers original paths |
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| IDXD object/table | ✅ | `sylpheed-formats/src/idxd.rs` | self-describing; ship/weapon stats verified vs known values |
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| XPR2 texture + cubemap | 🟡 | `sylpheed-formats/src/texture.rs` | de-tile + A8R8G8B8; **colours unverified** (dynamic item) |
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| T8aD 2D texture | 🟡 | `sylpheed-formats/src/t8ad.rs` | ~85% decode; **colours ✅ CONFIRMED** ([k8888](structures/texture-color-k8888.md)); ~15% variants deferred |
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| RATC bundle | 🟡 | `sylpheed-formats/src/ratc.rs` | child listing confirmed; one level deep |
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| LSTA sprite list | 🟡 | `sylpheed-formats/src/lsta.rs` | inline T8aD frames |
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| IXUD subtitle | 🟡 | `sylpheed-formats/src/ixud.rs` | timed cues; **movie↔track link unknown** (dynamic item) |
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| Fonts (ttf/otf/ttc) | ✅ | `sylpheed-formats/src/font.rs` | standard OpenType, parsed via ttf-parser |
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| XBG7 mesh | 🟡/❔ | `sylpheed-formats/src/mesh.rs` + `tests/mesh_disc.rs` ([xbg7](structures/xbg7-mesh.md)) | weapons/props: declaration-driven variable stride (36 models), GPU-confirmed. **Stage containers: 5662 sub-models across 22 stages** via content-anchored grouped pools (`stage_models`). Quantized hero bodies (DeltaSaber `f004`) still declined |
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| Capital-ship part placement | 🟡 | `sylpheed-formats/src/ship.rs` (static) + [runtime capture](ship-placement-runtime-capture.md) | hull placement static-exact; external parts approximate statically. **Runtime capture** (Canary F10 → VS-constant WorldView) gives ground truth — validated on `e106` destroyer; not yet baked into the viewer |
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| Weapon fields defaulted on disc | ✅ | [runtime struct](structures/weapon-struct-runtime.md) · [DATA SHEET route](weapon-datasheet-runtime.md) | **Solved.** Canary maps guest RAM into `/dev/shm`, so the parsed `Weapon`/`Shell` objects are readable live; their layout is solved against disc ground truth (zero contradictions over 100+ records). All 126 weapons, exact numbers, no story progress needed — [4 393 values](captures/weapon-runtime-fields.csv) the disc does not carry. Supersedes the letter-bucket limit of the DATA SHEET route, which now serves as the independent cross-check |
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| Unit (craft/vessel) fields defaulted on disc | ✅/🟡 | [runtime struct](structures/unit-struct-runtime.md) | The parsed `unit\UN_*.tbl` definition object, vtable `0x820af844`, ≥`0x380` bytes, one per unit — **discovered, not assumed** (`unit_discover.py`), and distinguished from the spawned-entity class `0x820af030` by being one-per-ID and byte-constant within a run. Across runs only pointer words move — `--crosscheck` proves **no reported field offset is run-dependent** (two words, `+0x2c8`/`+0x2d0`, are stage-dependent and remain unidentified). 27 fields ✅ (21 units, 7 runs); the `Maneuver` block is **schema declaration order, 4 bytes/field, base `0x9c` with a two-slot gap after `AA_Roll_Min`** (29 anchors, 0 conflicts), which also pins 5 fields *no* disc record ever values. Angles are **radians at runtime, degrees on disc**. Unlike weapons, unit definitions are instantiated **per stage**, so coverage (21/110) grows by visiting missions — but a defaulted field is **not** a global constant: `Size_Y` provably inherits `Size_X` (7 independent units, 6 distinct values), and three more sibling rules are recorded ❔, recovering 65 values in units never visited — [values](captures/unit-runtime-fields.csv) |
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| UI screen layout (`.rat`) | ✅/🟡 | [ui-rat-layout](structures/ui-rat-layout.md) | One pak per UI screen; each RATC = one (context × language) build; every `<name>.t32` sprite has a `<name>.rat` **layout record** (BE u32; 1280×720 design space; scale/tint/X/Y, keyframes for animated elements, `opt ` link to the focused state). **The tutorial PAUSE menu and the title main menu both rebuild pixel-accurately from the disc.** `loop1.rat` (screen-level draw order) not yet decoded |
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| Save file (`savedata`) | ✅/❔ | [savegame-format](structures/savegame-format.md) + [`tools/re-capture/savegame.py`](../../tools/re-capture/savegame.py) | `GDHA` container, zlib payload, chunk stream (`GDAA` / phase name / `GHAD` 122 B progress block / 16×20 B slot table / trailer). **Container and layout read off the title's own serializer `0x822C00E8` and verified by a byte-identical round-trip**; the whole save is 545 B. Payload offsets are also the live save object's offsets (`save+8` GHAD, `save+136` slots). Field *meanings* are ❔ — only the phase name, the slot count and the FILETIME are confirmed (the latter cross-checked against the content header's own display string). Naming the rest needs a second save to diff |
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## Runtime / dynamic-capture technique
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| Technique | Conf. | Spec | Notes |
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|-----------|-------|------|-------|
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| Live guest-memory read | ✅ | [`tools/re-capture/gmem.py`](../../tools/re-capture/gmem.py) | Canary backs the guest address space with `/dev/shm/xenia_memory_*`; guest VAs map in through Xenia's fixed table. Full-RAM search ~0.2 s (sparse, `SEEK_DATA`). No debugger, no emulator patch, game keeps running |
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| IDXD object layout solver | ✅ | [`tools/re-capture/weapon_runtime.py`](../../tools/re-capture/weapon_runtime.py) | Scan RAM for a class's vtable → enumerate its objects → brute-force `(field, offset, encoding)` against the disc records. Accepts a binding only on **zero** contradictions. Generalizes to any IDXD-backed definition |
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| Live entity state, anchored on the definition | ✅ | [`tools/re-capture/own_state.py`](../../tools/re-capture/own_state.py) · [autopilot](autopilot-memory-driven.md) | An undamaged craft holds its definition's own numbers, so a *solved definition field* locates the matching live field without a value scan: definition `HP` (1500) → **hull at `position+0x154`**, confirmed by a trace across a death (30/60/90 per hit, negative at 0). Reusable for any live counter whose maximum the definition carries |
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| Mission / escort state, every entity's hull | ✅ | [`tools/re-capture/mission_state.py`](../../tools/re-capture/mission_state.py) · [escort state](mission-escort-state.md) | `hull = position + 0x154` is a property of the **entity class**, not of the player object: at t=0 it equals each entity's own definition `HP` across 7 classes and 5 distinct HP values (turret 100, fighter 500, destroyer 10000, cruiser 30000, **ACROPOLIS 25000**), falls under fire (780 damage events in 240 s), goes negative at death, and the object then leaves the heap. So an escort objective is scoreable live — `UN_f101_TCAF_Acropolis` measured at 25000 → 23038 over 240 s, attack starting only at t≈170 s. `REMAINING OB` counts objectives, not hostiles (012 on the HUD vs 118 live ADAN); its address is still ❔ |
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| In-flight control mapping | ✅/🟡 | [`tools/re-capture/fire_probe.sh`](../../tools/re-capture/fire_probe.sh) · [controls](flight-controls-runtime.md) | Measured by holding each pad input and photographing the HUD ammo counters: **`RB` = nose gun** (6000→5956 in 4 s, ~11 rounds/s, HEAT rises), **`Y` = main mount** (missiles, 300→299), d-pad = **tactical map** overlay, nothing else moves a counter. No target-cycle input exists — the `TARGET` marker is present with nothing pressed, so targeting is automatic and a missile lock is **time-on-target**. That, not target choice or ballistics, is what caps lethality at 2 kills per 98 missiles |
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| Input → dynamics calibration | ✅ | [`tools/re-capture/ctrl_probe.py`](../../tools/re-capture/ctrl_probe.py) · [`binq.py`](../../tools/re-capture/binq.py) | Hold each pad input in turn and measure the craft's speed as displacement/s of its own position triple — no speed field needed first. Settled the throttle: **`RT` accelerates, `LT` brakes, and the setting persists** (488 → 1510 → 174 units/s), overturning an earlier field-scan conclusion |
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## Functions / code paths
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_None documented yet — populated during the dynamic-RE phase._
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| Function | Conf. | Reimpl. | Summary |
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|----------|-------|---------|---------|
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| — | — | — | — |
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