Static only. Last commit left "REQUIREMENT is a bit index into a progress
bitfield" with the space unidentified. It is the achievement space, and both
halves are now readable off the disc and the executable.
- GamePart_Debriefing (0x8218CF38-0x82191B18) awards them: sub_8218F9A8 walks
the on-disc ACHIEVEMENTS_REQUIREMENTS list (tables.pak #16, schema 744c0519),
and for entry index n tests bit n, evaluates the entry when clear, and sets
the bit when satisfied. The list is literally ACHIEVEMENT01..ACHIEVEMENT24 --
24 entries, which is exactly where the challenge gate splits word A from
word B.
- The XEX carries the definitions: XACH at .pe 0x8FBCBC, 36-byte records
{id, name_id, unlocked_desc_id, locked_desc_id, image_id u32, gamerscore u16,
pad, flags u32, 16 zero bytes}, strings from one XSTR per language (English is
table #5). tools/xach_dump.py parses it. SELF-CHECK: the 24 gamerscores sum to
exactly 1000, the retail total -- a wrong stride does not land on a round 1000.
- The two sources agree on ORDER independently: the requirement types
ShootDownAircrafts 1000/10000, ShootDownShips 100, ShootDownWeight MegaTons,
GetAllWeapons and GetAllAchievements line up with ids 19-24 exactly as XACH
names them. So bit n <-> achievement n+1 is evidence, not inference. (Those
last two are requirement TYPES, not debug cheats, despite how they read.)
- Corollary: TimeAttack's REQUIREMENT 16 -- the one value that sits in direct
value-before-key adjacency, so it survives IDXD dedup -- is bit 16 =
achievement 17, "Solar System Defense Award", i.e. finish the story campaign.
The other five values (25-29) are >= 24 and so index word B, a second flag
space, plausibly a challenge-clear chain. Still 🟡.
REFUTED, from the last commit: the stores to +1956 in 0x822AF278 / sub_822C8748
are NOT this singleton. That object comes from 0x822CEB30, checks a +2652 flag
and stores string POINTERS at +1956/+2024 -- and a pointer ANDed with 1<<n is
meaningless as a gate. So nothing in the image writes this singleton's +1956
field-wise, and where the mask persists (save vs Xbox profile) is open. XEX
imports are by ordinal, so absent XamUser* strings are not evidence either way.
Static only. Bounding each GamePart's code block by its factory creator thunk
(id -> creator recovered for 22 of 24 registrations at 0x8280C000-0x8280F800)
puts GamePart_ChallengeMission at 0x82187E60-0x8218CF10. Resolving every string
that block references gives the screen's config schema, and the record itself is
on disc -- tables.pak schema 54a10697, one copy per language, English entry #64.
Six missions: TimeAttack (record Time), ScoreAttack (record Points) and
Extra01..Extra04, each with MISSION_ID / REQUIREMENT / REQUIREMENT_DESC /
THUMBNAIL / STAGE_DESC / NEW_STAGE and a NORMAL_BUTTON / GRAY_BUTTON pair -- so
the screen always lists all six and greys out what is not earned.
THE GATE (0x82189970-0x821899D8), read off the code:
REQUIREMENT absent -> available
REQUIREMENT == "Always" -> available
else n = atoi(REQUIREMENT)
n == 0 -> locked
n < 24 -> test bit n of the word at singleton+80
n >= 24 -> test bit (n-24) of the word at singleton+1956
The singleton is 0x821707C0 (lazy, global 0x828F48BC). So availability is one
bit in a progress bitfield and REQUIREMENT is a bit INDEX -- not a stage number,
score or difficulty.
Values per mission are 🟡: the pool's numeric tokens are 16/25/26/27/29 and
24/28 already appear earlier as font metrics, so they would be deduped -- which
fits 24..29 but IDXD dedup makes positional pairing unsound here, so it is
recorded as a hypothesis, not a table.
Negative: the requirement TEXT is not in GP_CHALLENGE.pak (TextIndex over it =
0 entries; its only prose is embedded font copyright). Its PATH is a per-language
branch the loader does not currently reproduce.
Next: three stores to +1956 sit in 0x822C7DD0 / 0x822C8748, the same region as
the save serializer 0x822C00E8 -- if the bits are save-backed, a hand-written
save unlocks all six challenge missions and the last 42 units become one run.
Static-only (no emulator, no pad input). Three findings, each with its own
evidence:
- The disc holds exactly 29 StageResource records in three families --
S01-S16 story, S18-S23 tutorial (all bg=Original), S24-S29 challenge, plus
Test. That is 16 + 6 + 6 + 1, matching weapon.tbl's stage01..16 /
tutorial01..06 / challenge01..06 key set exactly. S17 does not exist.
GP_CHALLENGE.pak has 0 IDXD objects -- it is the menu screen; challenge
missions reuse GP_MAIN_GAME_E.pak's records.
- The GamePart id table is at 0x820A1630 (29 ids). Indices are confirmed by
the image's own RegisterToFactory<N, class silph::GamePart_*> text, not by
position: GP_CHALLENGE = 26, GP_TUTORIAL = 25, GP_BUNK = 10.
- The stage loader selects its config section from a mission-KIND field at
object+144: 3 -> EXTRA, 5|6 -> CHALLENGE, else FILE (two independent sites,
0x82184df0 and 0x82185ed0; two more classify {3,5,6} as one group). The
constructor sets it to 0 and every write inside the class only clears it,
and no immediate 3/5/6 store to it exists image-wide -- so the kind is
supplied by the launching GamePart, never derived from the stage number.
That last point is a mechanism (unproven) for why patching the save's stage
field to 27 kills the load: the record is a challenge stage but the kind stays
FILE. Names an untried, zero-cost discriminator -- try stage 18-23.
Also flagged, not resolved: roster_target says S10 (a STORY stage) still
fields an unharvested unit, which contradicts the "story campaign complete"
claim by one unit.
