Files
Sylpheed/docs/re
Sylpheed RE agent e8158f2dfd re: Stage\script.tbl's 11 non-MISSION fields, and the mission dialogue table
structures/mission-script-ssb.md owns this manifest and names its 40
fields but never read the 11 that are not MISSION<n> = StageNN.ssb.
They are DIALOG_MESSAGE, DIALOG_LOCAL_STRING, FONT (+size), TEXT_POS,
TEXT_LINES and the five pgmsg_*.prt.  Two sibling records were also
unread: GP_TEST (PATH = dat\GP_TEST\, a debug archive not on the disc)
and TEXTS (a second text style).

Probed 7 values x 33 prefixes x 41 archives.  One resolves:
message\MissionDialogMessage.tbl, in all six GP_MAIN_GAME_* paks --
200 records, 25280 bytes, every name S<NN>_P<n>_<KIND> with five kinds
40 each (HINT_PAUSE, HINT, OBJECTIVE, GRAPH, LOSE), fields positional
and tagged 0..3, each value a message key.  An index from (stage,
phase, kind) to the localised strings, on the same S<NN>_P<n> keying
the ISL corpus already uses.

Control: the 40 stage-phases span stages 1-16 and 24-29 -- a subset of
the 28 shipped, and the six with no hints are exactly 18-23, the
tutorials.  A fifth independent route to the story/tutorial split, and
it gives the phase count per stage.

The other six do not resolve, with the control in the same sweep:
MissionDialog_local_string.tbl and all five pgmsg_*.prt are not a pak
entry under any of the 33 prefixes, while
message\MissionDialogMessage.tbl and Stage\script.tbl both resolve in
6 archives.

name_hash is CASE-INSENSITIVE (message\ == Message\); tag_hash is not.

New structure doc, artefact and regenerator; the other five artefacts
regenerate byte-identical.
2026-08-27 13:37:31 +00:00
..

Reverse-engineering knowledge base

This directory is the spec-side of the clean-room: it records what the original Project Sylpheed binary does (behaviour) and how its data is laid out, so that the Rust port can be implemented from these specs without re-deriving anything and without ever copying original code.

It exists to answer one question fast: "do we already know how X works, and how sure are we?"


The one rule that matters

Never document a claim more confidently than the evidence supports, and never paste original code here.

A wrong-but-confident note is worse than no note: someone builds on it and the bug hides for weeks. Every entry therefore carries an explicit confidence and its evidence. This mirrors the project method — measure the oracle, never infer; refute before believing.

Clean-room firewall

  • Allowed: behaviour descriptions, field offsets/types, formulas, state machines, observed input→output pairs, and references to the original by address (sub_821B68C0) or to xenia-rs/sylpheed.db.
  • Forbidden here and in crates/: pasted decompiled C/C++ or verbatim disassembled function bodies presented as the thing to reimplement. Cite the address; describe the behaviour in your own words. Disassembly is a tool for understanding, not a source to copy.

Confidence levels

Level Meaning Bar to reach it
CONFIRMED Behaviour verified against ground truth. ≥2 independent observations or one observation cross-checked against an oracle (canary framebuffer, a known-correct value, a second code path).
PROBABLE Strong single-source inference. One clean observation, or an unambiguous static read of the disassembly.
HYPOTHESIS Educated guess, not yet tested. Anything else. Must say what would confirm/refute it.

The status markers

The table above is the confidence scale. The markers that appear in BACKLOG.md and the structures/ pages are a separate, and until now undefined, vocabulary. They mean:

Marker Meaning
Confirmed — verified against ground truth.
🟡 Partial: true as far as it goes, or true under a stated assumption.
Open question. Nobody has answered it yet.
🔴 Refuted — shown false — or blocked by something the container cannot do.
A specific claim that was tried and failed. Prefer 🔴.
🚧 Work started and not finished.

🔴 never means "we have not run it yet." That is or 🚧. Reserve 🔴's "blocked" sense for a real limit of the box — no push credentials, no hardware Vulkan (lavapipe only), or a decision only the user can make. The box can run the emulator, script input, screenshot, read guest memory, and build and test Rust, so "needs a run" is never a blocker. This paragraph exists because the marker was undefined for 98 uses and three of them were mislabelled that way.

Promotion requires new evidence, not re-reading the old evidence. A HYPOTHESIS that "looks right again" is still a HYPOTHESIS. Only an independent check promotes it. If evidence later contradicts an entry, demote it and record the contradiction — do not silently edit the conclusion.


When to document

  • Right after a function/structure crosses from HYPOTHESIS to at least PROBABLE — before moving to the next code path, so the knowledge isn't lost or re-derived.
  • Whenever confidence changes (up or down) — append to the Evidence log, don't overwrite.
  • Not while it's still a pure guess with no evidence — a one-liner in the relevant backlog/plan is enough until there's something to stand on.

What to document

  • Functions/code pathsdocs/re/functions/<name>.md (one file per function or tight cluster).
  • Data structures / formatsdocs/re/structures/<name>.md.
  • Keep the index in INDEX.md (one line each: name · confidence · one-line summary).

Use the templates: _TEMPLATE.function.md, _TEMPLATE.structure.md.


How we find and confirm code paths (the toolchain)

Everything joins on the guest virtual address (PC) — code addresses are fixed by the XEX load, identical across our emulator and canary.

  • Static (cheap, try first): xenia-rs/sylpheed.db (DuckDB: 25 481 functions, xrefs, strings, vtables, imports). Query with xenia-rs/zq.pyzq.py grep <str>, zq.py xref <addr>, zq.py dis <lo> <hi>, zq.py fn <pc>. Entry points are usually a string (zq.py grep MSG_DEMO) or an import (movie/XMA API) xref'd back to the loader.
  • Dynamic (when static is ambiguous): run xenia-rs with its probe suite — --pc-probe / --audit-pc-probe-hex (fires at block entry), --mem-watch (mid-block reads/writes of a VA), --lr-trace (call/return chains), --trace-instructions, --dump-addr (read guest memory). These already exist; prefer them over hacking canary.
  • Oracle (correctness ground truth): canary — the Wine cross-build xenia-canary/build-cross/bin/Windows/Debug/xenia_canary.exe (the native Linux ELF crashes / does not run — do not use it). This is the only emulator that reaches the in-game menu; our xenia-rs never got past the intro video. Use canary to observe output (capture its framebuffer for texture colours), not usually to instrument code — though its build-cross toolchain does compile, so small C++ probes + rebuild are possible when needed. Run muted, one emulator process at a time, point it at the real ISO (not the symlink).

⚠️ VA-equality caveat: join code by PC (fixed), but never assume a data VA holds the same bytes across emulators — allocators differ. Compare data by content/layout.