With word A = 2 the screen lists Stage01 SELECTABLE, carrying a High Score and a
Best Time, and Stage02-Stage08 GREYED OUT. One cleared stage, one selectable
entry, at the bit index that names it -- the mask's meaning is now visible on
screen rather than inferred from disassembly.
Two runs, identical navigation, fresh boot each:
control word A 0x00000002 -> MISSION SELECT opens normally
poked word A 0xFFFFFFFF -> MmAllocatePhysicalMemoryEx fails on 128 MB,
guest throws, Xenia shows "Disc Read Error"
So last commit's heap failure was caused by the poke, and by a careless one:
0xFFFFFFFF claims stages that do not exist (0, 17, 24-31 in word A). Poking only
real story ids (0x0001FFFE = stages 1-16) does not blow the heap. That the list
screen changes behaviour with the mask is itself evidence word A feeds it.
Getting a trustworthy control took three tries, and every failure produced a
plausible wrong answer rather than an error:
1. the title-glyph oracle fired during the ATTRACT MOVIE, so A was pressed at
nothing and the run "reported 0 failures" for a screen it never reached;
2. Xvfb keeps the previous instance's framebuffer until the new one draws, so
a screenshot seconds after launch showed the OLD run -- "MAIN MENU reached
after 1s", against a process that no longer existed;
3. a single-pixel "is NEW GAME white?" test matched a white LOADING FLASH.
Fixes, all in challenge_probe.sh: blank the root and refuse screen oracles for
the first 40 s; identify a screen by a PATTERN of sampled points (white text AND
the dark panel behind it), not one pixel; require two consecutive samples. The
new oracle was validated offline against all six saved screenshots and accepts
exactly the one real main menu.
General lesson worth the words: a navigation oracle that can only fail by
returning the wrong screen will happily produce a whole run of confident,
meaningless results.
Booted the title and read the two gate words live:
0x828F40C0 = 0x00000002 word A
0x828F4814 = 0x00000000 word B
Word A = 2 = bit 1. The profile's save is Stage 02 "At Standby" -- stage 01
cleared -- so the mask is exactly one bit, at the index of the one cleared
stage, 1-BASED. Reproduced across two cold boots. That confirms against a known
progress state, on the real game:
- the singleton is the static object at 0x828F4070, as derived statically;
- word A is a cleared-stage bitmask (not achievements, not a stage number);
- bit index = stage id, 1-based, so TimeAttack's REQUIREMENT 16 means "clear
stage 16" -- the last story mission;
- word B is the challenge half and is 0 on a story-only profile.
New tools: gpoke.py (live guest-memory WRITE, companion to gmem.py, prints
before/after for every word), pad.py (drives the new --hid=file pad; replaces
vgamepad, which leaked to the host through /dev/uinput), challenge_probe.sh
(one blocking session: boot, wait for title, drive in, poke, screenshot).
Poking both words did NOT surface a challenge entry in EXTRAS -- and that menu
was built 26 s after the poke, so it is not staleness. Entering MISSION SELECT
then failed, but the log names the real cause and it is not the gate:
MmAllocatePhysicalMemoryEx could not satisfy a 128 MB request (parent free
30633/131072 pages), the guest threw a C++ exception, and Xenia surfaced its
generic "Disc Read Error". It is preceded by "BaseHeap::Release failed because
address is not a region start" -- a failed release leaking the range. Recorded
as an emulator heap problem, with the control run (same navigation, no poke)
named as the next step.
