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Both defects from the previous iteration are fixed by measuring instead of assuming, and the fix immediately promotes a 🟡 result to ✅. Labelling: the previous probe assumed object+0x04 -> name_record+0x10 -> char* and resolved 0 of 116. wave3_probe.py searches for the chain per record instead, the way unit_discover.py does, and resolves 116 of 116 -- every one through the pointer at +0x04 with the string at delta 0x00, not 0x10. The 0x10 belongs to the definition object (vtable 0x820af844); the spawned-entity record (0x820af030) uses 0x00. Carrying one over to the other cost the last run. Stride: measured, not assumed. Gaps between consecutive records are min 32, median 800, with common values 800, 640, 608, 576, 416 and 32. There is no fixed record size, so the old RECLEN=0x200 window truncated large records and overran small ones -- which is why its busiest fields were the last words of the window. Future diffs must bound each record by the next record's address. With labels available, the "116 records == 116 roster members" claim was tested properly and is promoted from 🟡 to ✅. The multiset of unit types matches the static roster exactly: Turret 21/21, e106 Destroyer 19/19, f106 Destroyer 14/14, f105 Cruiser 11/11, ASFrigate 9/9, ISCMissile 9/9, Attacker_S 9/9, e105 Cruiser 7/7, DeltaSaber_T 7/7, ArrowHead 6/6 -- 10 of 10 exact. A coincidental total is possible; a coincidental distribution over ten unit types is not. The game allocates one record per roster member at mission load. Not settled: REMAINING OB at 0xbdb59668 held 95748078 unchanged all run. That address is known to be run-dependent, and this was one of the misses, so the run cannot say whether the pilot killed anything. Re-hunting it is a precondition for the kill-versus-no-kill test, not an optional extra.
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 toxenia-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. |
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
HYPOTHESISto at leastPROBABLE— 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 paths →
docs/re/functions/<name>.md(one file per function or tight cluster). - Data structures / formats →
docs/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 withxenia-rs/zq.py—zq.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-rswith 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; ourxenia-rsnever got past the intro video. Use canary to observe output (capture its framebuffer for texture colours), not usually to instrument code — though itsbuild-crosstoolchain 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.