The freeze's named next step is more expensive than it looked, and the reasons
are recorded before anyone starts it: xenia's stack walker is a TWENTY-LINE STUB
on POSIX (Create logs "unimplemented" and returns nullptr), so
ThreadDebugInfo::guest_pc is never filled here; PPCContext carries no live PC
either. A reverse host->guest map is buildable - the code cache already learns
the mapping in OnCodePlaced - but that plus a way to sample another thread's RIP
is a real emulator feature, not a patch.
The cheap route that does exist: gdb is installed and ptrace_scope is 1, so
attaching to a running emulator is refused but launching it UNDER gdb is not -
run-canary execs $XENIA_BIN, so a wrapper that execs "gdb --args <real binary>"
keeps the lockfile and flags and makes gdb the parent. That would separate
"spinning in guest JIT code" from "spinning in a xenia loop", which is the fork
this is stuck on. Not attempted yet.
ob_bitflag now locates the counter itself from the three addresses measured so
far, instead of refusing when the default one is wrong. That costs no
transitions, and with roughly half of all runs ending early, transitions are the
scarce resource.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
ob_bitflag.py is the follow-on the word-level refutation named: for every 4-byte
offset in the window and every one of its 32 bits, count how many entities have
it set, keep the pairs whose count is exactly the counter, and require them to
match again after a transition. Both polarities, since an objective could be
marked by a bit that is CLEAR on it.
Three runs, no verification, and the reasons are recorded: run 1 gave 187 + 33
candidates at counter 4 and then reported "the counter never moved" for 700 s -
about a mission that had ENDED in GAME OVER partway through; run 2 hit the same
dead mission; run 3 had the counter at a different address (the guard refused,
correctly) and then froze after one filter.
The hole is closed. frozen() asks whether the guest is ANIMATING, and the GAME
OVER screen animates happily - mean colour (114,22,63) - so every liveness check
passed while the mission was over. frozen.in_flight() classifies the screen with
screen_id, and ob_hunt/ob_flag/ob_bitflag now abort with NO LONGER IN FLIGHT.
That is the second confident negative in this investigation that was really about
a dead world, so the rule is written down: before believing "X never happened",
show that the thing that would produce X was still running.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
