# Project Sylpheed — reverse-engineered symbol map

Durable record of guest functions/data in the retail title (`default.xex`,
base `0x82000000`) that have been positively identified by RE. Addresses are
guest virtual addresses. This is the source of truth for names; the DuckDB
`sylpheed.db` (this dir) `functions.name` column can be re-stamped from here
with `apply_re_symbols.sql` (names are wiped on a full DB regen).

Confidence: **H** = behaviour proven (reproduced/verified against data), **M** =
strongly inferred from disassembly, **L** = tentative.

## Archive (IPFB `.pak`) subsystem

| Address | Name | Conf | Description |
|---|---|---|---|
| `0x824609C8` | `Pak_FindEntryByName` | H | Look up a TOC entry by path. Args `(r3 = pak object, r4 = char* path)`. Calls `Pak_HashPathName(path)`, then binary-searches the sorted 12-byte TOC (base `pak+4`, count `pak+8`, stride 12; compares the 32-bit `name_hash`). Returns the matching record pointer or 0. |
| `0x82460928` | `Pak_HashPathName` | H | Duplicate `r3 = char* path`, lowercase it in place (`Str_ToLowerAscii`), hash with `Sylph_NameHash`, free the copy, return the 32-bit hash. This is the path→key bridge. |
| `0x82455C78` | `Sylph_NameHash` | H | The IPFB TOC / cache-path name-hash. See [Name-hash](#name-hash-sylph_namehash). Input must already be lowercased. `r3 = char*` → `r3 = u32 hash`. |
| `0x825F4F90` | `Str_ToLowerAscii` | H | In-place ASCII lowercase (`A`–`Z` → `+0x20`); other bytes pass through. `r3 = char*`. (When `r3 == 0` it takes an unrelated init branch.) |
| `0x824607B0` | `Pak_IsIPFBHeader` | H | Validate an IPFB header. Loads the header's first word and checks it equals `"IPFB"` (`0x49504642`) via a delta trick: `first_word - 0x49504620 == 0x22` (`'B' - ' '`). `r5 = header ptr`. Returns bool-ish in `r3`. |
| `0x82460AD0`… | *(pak header parse, unregistered container)* | M | The pak-open/validate path around `0x82460DC0`–`0x82460EC4` builds an expected-header template (`"IPFB"`, `0x10000000` flags) on the stack and calls `Pak_IsIPFBHeader`. Function-boundary detection missed the enclosing frame (entry ≈ `0x82460E34`). |
| `0x82458508` | `Archive_StreamReadCrc32` | M | Streaming block reader that validates content with a reflected CRC-32 (init `0xFFFFFFFF`, final `~`, table at `g_Crc32Table`). Compares the computed CRC to a stored expected value (`state+144`). This is a **content-integrity** CRC, *not* the name-hash. |
| `0x828992F0` | `g_Crc32Table` (data) | H | 256-entry reflected CRC-32 lookup table. Referenced only by `Archive_StreamReadCrc32` and its sibling loop at `0x82457AF8`. |

## 3D resource subsystem

| Address | Name | Conf | Description |
|---|---|---|---|
| `0x82640290` | `Res3D_LoadMeshChunk` | L | 3D-resource loader: walks 12-byte records, checks chunk tags (`0x1A22AA26`, `0x2DA2AA24`), and copies `float` triples (x/y/z vertices) via `lfs`/`stfs`. Part of the DefTables/`machines\<model>\…` mesh path. |

## Name-hash (`Sylph_NameHash`)

Per-byte Barrett-reduced polynomial hash over the **lowercased** name:

```
A = 0 ; B = 0
for each (sign-extended) byte c of the lowercased name:
    A = (A << 8) + c                                              # 32-bit
    A = A - (((A * 0x8003_1493) >> 32) rol 9 & 0x1FF) * 0x00FF_F9D7   # A mod 0x00FF_F9D7 (no final fixup)
    B = B + c
hash = ((B & 0xFF) << 24) | (A & 0x00FF_FFFF)
```

- Modulus `0x00FF_F9D7`, reciprocal `0x8003_1493` (the `mulhwu`/`mullw` Barrett step).
- Low 24 bits = modular polynomial hash; top byte = 8-bit additive checksum of the bytes.
- No trailing conditional subtract — the value is defined by the exact op sequence.
- Faithful Rust reproduction: `sylpheed-formats/src/hash.rs` (`name_hash`).

**Verified** against retail TOCs: `name_hash("files.tbl") == 0x8342_1153`,
`name_hash("eng\\weapon.tbl") == 0x900C_8DCD`, `name_hash("eng\\strings.tbl") == 0x10C8_0B87`,
`name_hash("jpn\\weapon.tbl") == 0x9E85_FEFF`.

## TOC key path conventions (preimages)

The 32-bit TOC key is `name_hash` of a **backslash** path with the entry's
internal identity string. Confirmed schemes:

| Scheme | Example | Where |
|---|---|---|
| `unit\<ID>.tbl` | `unit\UN_f001_TCAF_DeltaSaber_T_EX5.tbl` → `0x7C96296C` | craft/ship entries in `GP_MAIN_GAME_*.pak` |
| `weapon\<ID>.tbl` | `weapon\Weapon_DSaber_P_wep_26_Missile.tbl` | weapon entries |
| `<lang>\<name>.tbl` | `eng\weapon.tbl`, `jpn\strings.tbl` | localized loadout/text tables |
| `<name>.tbl` | `files.tbl` | root manifest |

`<ID>` = the entry's internal `ID` field (IDXD string pool). Craft/weapon
entries also self-describe by content, so stats are readable without the key.

## Open threads

- **Defaulted IDXD fields** (`*Ratio`, the `*Count` family) carry no value on
  disc. The large 16-byte-record binary node table inside a craft IDXD is
  **spatial/mesh data**, not defaults (ruled out: it is not keyed by
  `name_hash(field_key)`). Defaults must live in per-`schema_hash`
  schema-definition tables (e.g. craft schema `0x43FAA517`) — location TBD.