# Challenge / EX missions — the stage set, the GamePart graph, and the kind field **Status:** ✅ for the static structure (stage set, GamePart ids, the config-section switch) and for the **unlock mechanism** (a bit test against the achievement mask); 🟡 for the crash mechanism and for which mission consumes which bit; ❔ for where the mask persists. **Method:** static only — `.pe` string/pointer analysis + DuckDB disassembly + disc records. No emulator run, no gamepad input. **Evidence:** [`captures/challenge-map.txt`](captures/challenge-map.txt), [`captures/challenge-screen-config.txt`](captures/challenge-screen-config.txt), [`structures/achievements.md`](structures/achievements.md); `examples/challenge_map.rs`, `examples/challenge_screen.rs`. ## Why this was worth doing The Route-B unit harvest is complete for the **story** campaign (68 of 110 units, 7 115 defaulted-on-disc values) and stalled there: the remaining units are `*_EX4` / `*_EX5` / `*EX` variants that only the challenge missions field. The save's stage field addresses those stage records — but setting it to **27** boots to the title and then the emulator **exits during the load**, while 1–16 all load normally. This note answers *what the challenge missions are on disc* and *why the stage field alone is not enough*, so the next runtime attempt is targeted rather than another probe sweep. ## 1. The disc has exactly 29 stage records, in three families ✅ `StageResource` (schema `0x3c9ae32e`) in `dat/GP_MAIN_GAME_E.pak`: | ids | count | `BackGroundID` | reading | |---|---|---|---| | `S01`–`S16` | 16 | Lebendorf … PD (real locations) | the **story** campaign | | `S18`–`S23` | 6 | `Original` (all six) | the **tutorial** missions | | `S24`–`S29` | 6 | Anastasis, Hargenteen ×2, Planet_Lebendorf, Lebendorf, Earth | the **challenge** missions | | `Test` | 1 | Earth | developer stage | `S17` does not exist. This **matches `weapon.tbl`'s sprite-key set exactly** — `stage01…16` + `tutorial01…06` + `challenge01…06` (recorded in [static screen config](#)) — which is an independent confirmation of the three-way split: 16 + 6 + 6 + Test = 29. The `Original` six carry ~43 tokens each while the story and challenge records carry 51–59, consistent with tutorials having no squadron/route/formation tables. ## 2. `GP_CHALLENGE.pak` is a screen, not mission data ✅ 151 entries, **0 IDXD objects** — sprites and layout only. So challenge missions are *not* a separate data set: they are ordinary `StageResource` records in `GP_MAIN_GAME_E.pak`, reached through a different menu. That is why the EX unit rosters show up in the same `EnumUnit_S` tables the story stages use. ## 3. The GamePart id table — the game's whole screen graph ✅ `.rdata` pointer array at **`0x820A1630`**, 29 entries, index = GamePart id: ``` 0 GP_TITLE 10 GP_BUNK 20 GP_STAGE_CLEAR 1 GP_ADVERTISE_DEMO 11 GP_READY_ROOM 21 GP_MISSION_LOG 2 GP_SELECT_STORAGE 12 GP_HANGAR 22 GP_GAMEOVER 3 GP_LOAD 13 GP_ARSENAL 23 GP_DEBRIEFING 4 GP_SAVE 14 GP_PILOT_LOG 24 GP_DIALOG 5 GP_EXTRAS 15 GP_SYSTEM 25 GP_TUTORIAL 6 GP_MOVIE_THEATER 16 GP_DEMO *26 GP_CHALLENGE 7 GP_MISSION_SELECT 17 GP_MAIN_GAME 27 GP_LEADERBOARD 8 GP_OPTIONS 18 GP_SELECTOR 28 GP_TEST 9 GP_MOVIE 19 GP_PAUSE_MENU ``` The indices are **not inferred from position** — the image carries the factory registration text, e.g. `silph::GamePartTask::RegisterToFactory<26, class silph::GamePart_ChallengeMission>::RegisterToFactory is failed!` and `<10, … GamePart_Bunk>`, both of which agree with this table. So `GP_CHALLENGE` is GamePart **26** and `GP_TUTORIAL` is **25**. ## 4. A mission-**kind** field selects the stage config section ✅ Immediately before the array above, `0x820A1600`–`0x820A162C` holds the stage-config key list: `BASE_INFO`, `StageResource`, `Background`, `PlayerUnit`, `EQUIIP_LIMITATION` *(sic)*, `MODEL_PATH`, `NEW_ITEM`, `LOADING`, `CHALLENGE`, `EXTRA`, `FILE`. The stage loader picks **one of the last three** by a field at **`object + 144`**, and the same three-way switch appears at two independent sites (`0x82184df0` inside the all-keys config reader, and `0x82185ed0` in `sub_82185E80`): ```asm lwz r11, 144(r30) cmpi r11, 3 ; == 3 -> "EXTRA" (0x820A2160) beq extra addi r11, r11, -5 cmpli r11, 1 ; == 5 or 6 -> "CHALLENGE" (0x820A2154) bgt file ; otherwise -> "FILE" (0x820A2168) ``` Two further sites (`0x82186a60`, `0x82186cb8`) classify the same field as `{3, 5, 6}` versus everything else — i.e. **EXTRA and CHALLENGE together are "not an ordinary story load"**. The field is initialised to **0** in the constructor (`sub_821783D8`, `0x8217851c`, alongside `+148 = 0` — the stage index — and `+132 = 2`, `+136/+140 = -1`), and every write to it inside this class (`0x82184b10`, `0x82185d48`, `0x82186ab4`) only *clears* it. Nothing in the image stores an immediate 3/5/6 into it, so the kind is **supplied from outside the class** — by whichever GamePart launches the mission — not derived from the stage number. ### 4.1 Why the stage-field probe crashes 🟡 That gives a mechanism for the observed failure: patching the save's stage field to 27 selects the `S27` **record** while the kind stays **0**, so the loader reads the `FILE` section for a stage whose config lives under `CHALLENGE`. A missing section then propagates into the load, and the title exits. It fits the evidence (1–16 fine, every 24–29 the same failure, `/dev/shm` empty and disk free, so not the resource trap) but it is **not proven** — proving it needs a run. **Cheap untried discriminator, no new tooling:** patch the stage field to **18–23** (the tutorials). If those also die, the failure tracks "record outside the story range", and the kind field is the likely gate. It has never been tested — only 1–16 and 24–29 were. ## 5. The challenge screen, its six missions, and the unlock gate ✅ The factory registration sites (`0x8280C000`–`0x8280F800`) give **id → creator** for 22 of the 24 registered parts, and the creators bound each class's code block. So `GamePart_ChallengeMission`'s methods are **`0x82187E60`–`0x8218CF10`** (between `GP_BUNK`'s creator `0x82187E38` and its own `0x8218CF10`). Resolving every string that range references gives the screen's whole config schema: ``` MISSIONS · MISSION_ID · RECORD_TYPE · REQUIREMENT · REQUIREMENT_DESC NORMAL_BUTTON · GRAY_BUTTON · THUMBNAIL · STAGE_DESC · TEXT_STAGE TEXT_RECORD · NEW_STAGE · "Always" · "Time" · BASE_INFO ``` **The record itself is on disc**, in `tables.pak` (schema `54a10697`, one copy per language — English is entry #64), *not* in `GP_CHALLENGE.pak`. It names six missions: | slot | `MISSION_ID` | buttons / thumbnail | record | |---|---|---|---| | 1 | `TimeAttack` | `Button_TimeAttack{,_Gray}`, `Thumbnail_TimeAttack` | `Time` | | 2 | `ScoreAttack` | `Button_ScoreAttack{,_Gray}` | `Points` | | 3–6 | `Extra01`…`Extra04` | `Button_Extra0N{,_Gray}` | — | `GRAY_BUTTON` is the locked art, `NORMAL_BUTTON` the unlocked art — so the screen always shows all six and greys out what you have not earned. Full dump: [`captures/challenge-screen-config.txt`](captures/challenge-screen-config.txt). ### 5.1 The gate is a bit test against a progress bitfield ✅ `0x82189870` builds the list, and `0x82189970`–`0x821899D8` is the availability decision for each mission: ```asm lookup REQUIREMENT in the mission record ; bl 0x82448C50 absent -> AVAILABLE == "Always" -> AVAILABLE ; strcmp, bl 0x825EDD20 else n = atoi(v) ; bl 0x825EDCD0 n == 0 -> LOCKED n < 24 -> bit n of word A n >= 24 -> bit (n-24) of word B bit set ? AVAILABLE : LOCKED ``` Word A and word B are read from a **singleton** (`0x821707C0`; the object pointer lives at the global `0x828F48B0`, with a construct-once flag at `0x828F48BC`) at offsets **`+80`** and **`+1956`**. So challenge availability is one bit in a progress bitfield, and `REQUIREMENT` is that bit's index — **not** a stage number, a score, or a difficulty. ### 5.2 The bit space is the game's 24 ACHIEVEMENTS ✅ The `< 24` / `>= 24` split is not arbitrary. `GamePart_Debriefing` (`0x8218CF38`–`0x82191B18`) walks a disc config list called **`ACHIEVEMENTS_REQUIREMENTS`** (`tables.pak` entry #16, schema `744c0519`) and, for entry index `n`, tests and sets **bit `n`** of an awarded-mask — and that list is exactly `ACHIEVEMENT01` … `ACHIEVEMENT24`, **24 entries**. The XEX's own `XACH` resource holds the matching 24 achievement definitions, summing to **1000G**, the retail total. Full table and record layout: [`structures/achievements.md`](structures/achievements.md). So **word A (`+80`) is the earned-achievement mask** (bit `n` = achievement `n+1`), and **word B (`+1956`) is a second, different flag space** that requirement values `≥ 24` index as `bit n-24`. ### 5.3 What the six requirement values are 🟡 The record's numeric tokens are `16`, `25`, `26`, `27`, `29`, and `24`/`28` are already in the pool earlier (they double as font metrics), so they would be **deduped away** if used. **IDXD dedupes the string pool, so positional key/value pairing is not sound here** (the same trap the movie/subtitle map hit) — with one exception: `16` sits *immediately* before `REQUIREMENT` (tokens 96 → 97), which is the documented value-before-key adjacency, so the **first** mission (`TimeAttack`) requiring **bit 16** is well-supported. Bit 16 is achievement **17, "Solar System Defense Award"** — *"great achievements during the campaign to defend the Solar System"*, i.e. **finish the story campaign**. That is exactly the shape of gate you would expect on the first challenge mission, and it is independent corroboration that the bit space is the achievement space. The remaining five values (`25`–`29`, all `≥ 24`) therefore index **word B**, not achievements — most plausibly a challenge-clear chain, since there are six challenge missions and word B's bits `0`–`5` would be `24`–`29`. Recorded as a hypothesis; resolving the per-mission pairing needs the record's binary index section, not the pool. **Negative worth keeping:** the requirement *text* (`TimeAttackRequirement`, `Extra01Requirement`, …) is **not** in `GP_CHALLENGE.pak` — building a `TextIndex` over it yields **0 entries** and its only wordy payload is embedded font copyright. The config's `PATH` is `dat\GP_CHALLENGE.pak+eng\`, a per-language branch, so those keys resolve through a naming scheme the current loader does not reproduce. Reading them would say in plain English what each mission asks for — worth one more attempt via `hash::TOC_NAME_SCHEMES`. ### 5.4 Why this matters operationally — and one lead already refuted If word A / word B are restored from the save, a **hand-written save with those bits set unlocks all six challenge missions** — and the savegame round-trip is already solved. That would turn the last 42 units of the Route-B harvest into one run instead of an unreachable menu. **The obvious lead is dead.** The three `stw`s to `+1956` in `0x822AF278` / `sub_822C8748` looked promising because they sit in the save serializer's code region — they are on a **different object**. That one is fetched through `0x822CEB30`, has a `+2652` flag the code checks first, and stores **string pointers** at `+1956`/`+2024` (built by `0x822D35F8`); a pointer `AND`ed with `1 << n` would be meaningless as a gate. So **nothing in the image stores to this singleton's `+1956` field-wise**, which means it is filled by a bulk copy or by a path not yet found. Two candidates remain and they need different levers: the **save** (hand-write it) or the **Xbox profile** (the emulator's profile data). Note that XEX imports are resolved **by ordinal**, so the absence of `XamUser*` name strings in the `.pe` is not evidence against the profile route. `+80` at least is handled as a small struct by address (`addi r4, obj, 80` → copy helper `0x82175110`, written back via `0x8216FF70`), which is what a serialised value object looks like. ## 6. The unlock condition, from the strings ❔ Three strings say challenge missions are *announced*, not menu-browsed: - `AVSCRIPT_COMMAND_ATTAINMENT_CHALLENGE_MISSION_CARGO_SCORE` — a mission-script command that grants challenge-mission attainment from a **cargo score**; - `DLG_CHALLENGE_MISSION_AVAILABLE` — the "a challenge mission is now available" dialog; - `DLG_GO_CHALLENGE_MISSION_MENU` — the prompt that takes you to GamePart 26. So the gate is plausibly an in-mission achievement, not a title-menu state — which is consistent with `Game Status = GAME_CLEAR` unlocking nothing (measured, refuted). Neither dialog key is reachable by xref: they are selected **by index** through a config lookup, exactly like the save screen's sprite keys, so there is nothing to grep back to. Naming the flag needs the challenge-availability check disassembled from the screen side. ## 7. What this makes actionable `roster_target` against the harvested CSV, with the stage families now named: | stage | family | roster units not yet read | |---|---|---| | `S27` | challenge | `f003_ArrowHead_EX4`, `e107_AAFrigate_EX4`, `e010_Attacker_S_EX4`, `e011_Attacker_B_EX4`, `e007_Turret_EX4`, `e008_TurretPlus_EX4` | | `S28` | challenge | `f004_DeltaSaber_A_Player`, `f001_DeltaSaber_T_EX5(_el)`, `f003_ArrowHead_EX5`, `f104_Battleship_EX5`, `f105_Cruiser_EX5` | | `S25` | challenge | `e101_SDBattleshipEX`, `e102_BattleshipEX`, `e105_CruiserEX`, `e108_ASFrigateEX` | | `S29` | challenge | `e101_SDBattleshipEX`, `e102_BattleshipEX`, `e105_CruiserEX` | | `S24` | challenge | `e105_CruiserEX`, `e106_DestroyerEX` | | `S10` | **story** | `e005_ADAN_ElanTypeQ_Margras` | ⚠️ **The `S10` row contradicts "the story campaign is complete."** One story stage still fields a unit that has never been read. Either `S10` was never flown (it is the smallest stage container on the disc — 7 XBG7 resources — so it may be a cutscene stage that is not flyable), or the completeness claim was one unit optimistic. Flagged rather than resolved: it costs one ordinary story run to settle. Remaining coverage: 42 units missing, of which the rosters above account for ~23. The rest are not in any stage roster table and need a different lever. ## Reproduce ```bash cargo run --release -q -p sylpheed-formats --example challenge_map -- cargo run --release -q -p sylpheed-formats --example challenge_screen -- python3 xenia-rs/zq.py dis 0x82184df0 0x82184e30 # the three-way section switch python3 xenia-rs/zq.py dis 0x82185ed0 0x82185f10 # the same switch, second site python3 xenia-rs/zq.py dis 0x82189860 0x821899f0 # the challenge availability gate ```