DoE CSV gained 6 switch-signal columns (switch_count_cumulative,
switch_current_slot, switch_*_readiness, switch_ticks_since), and verifying
them with a boot-time HB-ON probe surfaced a real livelock: the preemption
checkpoint could fire inside a VM-EXEC-nested execute_colon_word() call and
switch away from a stack it didn't own, parking a borrowed region of the
caller's stack under the wrong VM's saved-context pointer. The trampoline
bounce was the visible (safe) half of this; the corruption was the quiet
half, live in every prior "clean" Stage 3 boot without ever showing up in
the log.
Fixed by gating the checkpoint on being at the outermost vm_interpret()
call (g_vm_interpret_depth / sk_vm_at_outermost_interpret(), vm_core.c),
per Bob's decision. Also fixed two related bugs found in the same pass:
g_switch_back_to was a single global stale after first entry, now per-VM
state (native_switch_back_to); note_switch_performed() fired on resume
instead of switch-out, now called before the switch.
Verified on all 3 architectures: steady log growth (no freeze), zero
leaked QEMU processes, DoE columns internally consistent, Hermes/Artemis
confirmed genuinely executing (not just trampoline-bouncing). Temporary
HB-ON boot probe reverted after capture.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016UNhH1mhi52i6Qihh7ZV5S
doe_log.c's per-heartbeat-tick CSV gains two columns: fleet_k_q48
(vm_physics_fleet_heat_sum() over ALL live VMs -- the genuine fleet-wide
conservation invariant K, not reconstructable from the 3 named-Tripod-
member heat columns already logged, which omit every identity VM's own
heat) and fleet_conserved (vm_physics_conserved() as 0/1). Requested
explicitly after the first heartbeat-telemetry analysis pass
(analysis-20260912/) omitted K entirely.
Kernel rebuilt on all three architectures, full 3x9x3 campaign rerun
(results-20260912-with-k/). K = 1.0000000000 (Q48.16 raw 65536) on every
one of 775 heartbeat-tick observations, sd(K) = 0, 100% fleet_conserved,
across amd64/aarch64/riscv64, nine identities, three replicates -- zero
deviation. Also a free regression check on both recent Stadium fixes
(§XVI/§XVII): neither disturbed the reservoir-transfer accounting K
depends on.
Found and fixed a tooling wrinkle along the way: fleet_conserved, being
the CSV row's very last field with nothing after it to bound a regex
match, can have a resumed trial digit merge into it with zero separator
on the wire -- combine.py now derives it from fleet_k_q48 directly (same
epsilon vm_physics_conserved() uses) instead of trusting the raw field.
fleet_k_q48 itself is unaffected either way.
Full analysis, discussion, and light/dark SVG->PDF figures written up as
a proper LaTeX report (report-20260912/report/std79_doe_report.pdf),
following experiments/bare_metal/analysis/report/bare_metal_doe_report.tex's
established style -- supersedes analysis-20260912/'s markdown-only first
pass as the primary deliverable for this dataset (kept, not discarded).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EXieurDfDSsDFdnSyusuWo
xhci_bringup() (HC reset, DCBAA, Command/Event rings, RUN/STOP) was
uncommitted and referenced an XHCI_WAIT_FOR macro that was never defined,
breaking the build. Wired all four wait sites to the existing
xhci_wait_bit() helper instead, matching each register/bit/polarity
needed (halt-before-reset waits for HCH set; HCRST, CNR, and post-RUN
HCH waits all wait for their bit to clear).
Also flipped g_doe_log_enabled's default from 1 to 0 -- the per-tick
[HADES][DOE] CSV export was flooding every boot log and slowing
interactive verification for no reason during ordinary acceptance runs;
HB-ON still re-enables it at the REPL for anyone running an actual DoE
campaign.
Three-arch acceptance: amd64/aarch64/riscv64 all boot clean to ok>,
zero DoE rows in any log. aarch64 and riscv64 both exited cleanly via
BYE with no exception, confirming the earlier SMC->HVC PSCI fix still
holds. Logs and DoE CSV artifacts from this run included.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HZ8kNoTuP63pbQtro4qvrm
Cursor (Captain Bob: "the only thing we need is a cursor"):
vt100_draw_cursor() draws a solid block at the terminal's current
position, called from repl.c after the prompt prints and after every
keystroke/backspace. vt100_erase_cursor() cleans up the one gap a static
cursor has -- Enter/newline moves away from the cursor cell without a
character draw ever overwriting it, which left a stray block behind
until this fix.
HB-ON/HB-OFF (Captain Bob: run a program with or without instrumentation
without rebuilding):
Converted per-tick DoE logging from a build-time flag (HEARTBEAT_DOE_LOG)
to a runtime one. doe_log_tick_row() now self-gates on g_doe_log_enabled
(default 1, matching the old default) instead of being compiled out
entirely; the call site in vm_runtime.c is unconditional. Two new FORTH
words, HB-ON and HB-OFF, flip the flag live. Removed the now-dead
HEARTBEAT_DOE_LOG plumbing: the Kconfig symbol, and the -D forwarding in
both LOADER_CFLAGS and KERNEL_CFLAGS.
Verified: three-arch clean QEMU boot + logs; dictionary word count 466
(463 baseline + ALT+TAB + HB-ON + HB-OFF, exactly the three words added
across this session); amd64 screendump confirms the cursor renders
correctly after real interactive typing.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
