ea7881acb3
Four float constants in ComputeBudget have a width a C++ port gets wrong by default, and the corpus exercises the boundary of exactly one. That one is now measured against the running game, with a control build that must fail and does. savings interest (double)0.01f boundary: treasury a multiple of 100 IN CORPUS debt interest (double)0.15f boundary: a negative treasury not in corpus research yield (double)0.85f boundary: research money mult of 40k not in corpus the three ResMod summed in f32 boundary: two of three non-zero not in corpus Three constants sitting beside those, in the same expressions, are EXACT doubles and must not be "corrected" -- so "widen every literal" is its own defect and the only safe procedure is to read each operand. Same pattern elsewhere in the chain: ComputeOutputFromRates multiplies by an exact 1.5 then a widened 1.2f two instructions later, and NormaliseOutputRates holds 1e-4 at BOTH widths. Live result (VM146, turn1-state.sav, three runs): the game pays 499 interest on a treasury of 50,000 and 380 on 38,100; the exact decimals pay 500 and 381. Every divergence in the control build lands on a multiple of 100 and nothing else diverges at all. Coverage stated as distinct states, not calls: 5 distinct treasuries, 2 on the boundary -- against the earlier green run's 20 distinct states, none on a boundary. BANKRUPTCY_PROTECTION_LIMIT_FACTOR read live: 3.29999995 = (float)3.3. Its file image is zero because the loader fills it at run time, so lane PL-3 could read the width and had to assume the value. The assumption was right and is now measured. Falsified: the difficulty-mods record does not sit inline at ServerPlayer+0x36c; that field is a heap pointer on all eight players. Recorded as a hypothesis with the measurement, not as a fact. Second finding, from the rule-19 control: turn1-state -> turn2 is NOT a deterministic pair. Three runs gave three post-turn autosaves differing in exactly four leaves -- one Singularity shadow empire's research pick and the derived checksum. Two of the three runs carried identical hooks, and the un-instrumented run was a third value, so this is the game and not the instrument. The determinism oracle stands for ref-turn2 -> turn3 and does not generalise to its neighbour; no lane should use this pair as a byte-match oracle. |
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|---|---|---|
| campaign | ||
| findings | ||
| ghidra | ||
| guides | ||
| notes | ||
| objects | ||
| scripts | ||
| tools | ||
| verify | ||
| .gitignore | ||
| README.md | ||
sots-re
Reverse-engineering worklog for Sword of the Stars (2006, SOTS1) — the 32-bit DX9 original + expansions. The nitty-gritty: static/dynamic analysis notes, Ghidra & ReVa scripts, function/struct maps, D3D9 call traces, decomp progress, findings.
Where this runs
Analysis lab on spicy (PVE, 192.168.3.201):
- CT111
sots-re— Linux workspace: Ghidra + headless ReVa server, radare2/rizin/cutter, binwalk. Hosts the Samba share and this repo's working tree at/srv/re-lab/notes. - VM140
sots-re-win10— Win10 runtime + dynamic analysis (x64dbg, Cheat Engine, RenderDoc/apitrace, DXVK→CPU-Vulkan for GPU-less rendering).
Infra (guests, storage, network, share, ReVa endpoint) is documented from the
system-maintainer POV in trikilli → services/re-lab.md. This repo is everything else.
Layout
findings/— the running findings log (append-only), one file per subsystem.ghidra/— exported scripts, data-type archives, struct definitions.traces/— D3D9 / Win32 API call captures + analysis.scripts/— helper tooling (loaders, extractors, parsers).notes/— session notes, scratch, hypotheses.
Ownership / legality
Game binaries come from the owner's own GOG/Steam copy. RE is for personal
interoperability, bug-fixing, and preservation. Binaries themselves are not committed
here (see .gitignore) — they live on the lab's Samba share /srv/re-lab/samples.
Campaign (how this repo is run)
A 4-agent crew (defined in ~/.claude/agents/re-*.md) runs the exploration:
re-quartermaster (backlog + board) → re-analyst (maps via ReVa) →
re-verifier (proves vs real data; old-vs-new differential once reimpl starts) →
re-scribe (files the note, links it, commits).
campaign/board.md— live status board (start here).- Live tracking = Forgejo issues on
alex/sots-re(labelsstatus/*are the kanban columns;type/*,conf/*).campaign/board.mdis the editable mirror — publish withscripts/forgejo_campaign.py bootstrap(needsFORGEJO_TOKEN). campaign/backlog.md— prioritized target queue.campaign/open-questions.md— unresolved threads.findings/_template.md— the record format every finding follows.findings/{objects,control-flow,subsystems}/— the growing engine map.verify/{parsers,traces,harness,results}/— validation: struct parsers now, golden-trace replay + shim compare-mode for reimplementation.ghidra/— exported scripts + datatype archives.
Approach & north star: findings/00-strategy.md. Binary facts: findings/01-fingerprint.md.
Sibling repo
alex/sots-engine — the from-scratch engine source (clean-room, public-capable). This repo keeps the
evidence + planning for both; binary facts cross over only via ghidra/addresses.json → tools/gen_addresses.py.
guides/re-windows-2000s-howto.md— annotated bibliography + how-to for RE of mid-2000s MSVC/DX9 Windows games, with our-experience call-outs.