Files
LithosAnanake/src
Robert Allan JamesandClaude Sonnet 5 43aa0a2a36 aarch64: arm the ARM Generic Timer -- CNTP/CNTHP TVAL+CTL, per-tick re-arm
Punch list §25 item 0.7 complete. This is what finally makes items 0.5 and
0.6 provably work end to end.

apic_timer_start(): writes CNTP_TVAL_EL0 (or CNTHP_TVAL_EL2 at EL2 --
aarch64_current_el(), same EL-aware discipline as 0.4-0.6) to
s_timer_period_tsc, then CTL.ENABLE=1/IMASK=0, followed by an ISB. The ISB
is not decorative: confirmed against Linux's own arch_timer_reg_write_cp15()
(arch/arm64/include/asm/arch_timer.h) that only the *control* register write
needs synchronising before the enable/mask state is guaranteed visible to
the interrupt pipeline -- TVAL/CVAL writes do not carry the same
requirement, which is why apic_timer_rearm() omits it.

TVAL is architecturally 32-bit but MSR-to-system-register is always a
64-bit instruction form -- passing a uint32_t operand directly failed to
build (-Wasm-operand-widths). Fixed by truncating to 32 bits ourselves then
zero-extending back to 64 for the operand, which supplies explicit,
provably-correct zeros in the RES0 upper field rather than depending on
unverified hardware behaviour -- Linux's own driver never exercises this
path (it always uses the 64-bit CVAL form instead), so there was no local
source to confirm the alternative against.

apic_timer_rearm() (new): re-writes TVAL only, no ISB needed. TVAL is
relative to "now," not an absolute deadline like riscv64's SBI interface
(item 0.3), so there is no drift-correction bookkeeping -- each write means
"N ticks from this instant." Wired into aarch64_irq_handler() and called
*first*, before heartbeat_tick(), matching riscv64_timer_rearm()'s ordering
discipline exactly: the ARM Generic Timer does not auto-reload, so a return
path that skips this leaves the interrupt condition latched, which the GIC
would redeliver the instant it's EOI'd -- a real storm, the same class of
failure item 0.6's verification investigated (and that time found absent,
because nothing was armed yet).

Verified: builds clean; every generated instruction checked against
disassembly, not just reviewed by eye (both EL branches, correct TVAL/CTL
register names, single shared ISB in apic_timer_start(), no ISB in
apic_timer_rearm()). Boots to ok> with no regression, dict_hash
0x3d4e1daf289da94f unchanged.

Rate measured directly against real wall-clock time via QEMU's own -d int
trap trace (same method as riscv64's item 0.3), two independent windows:
1,090 interrupts over 11.05 s (98.679 Hz) and 4,031 over 40.88 s (98.614 Hz)
-- consistent across both, so this is a real, small, systematic bias
(~1.3-1.4% slow), not measurement noise from polling granularity, which
would have shrunk with the longer window and did not. Attributed to genuine
per-interrupt service latency: TVAL is rewritten mid-ISR, so the trampoline
save/restore, GICC_IAR read, EL branch and GICC_EOIR write all lengthen the
effective period slightly versus the nominal 10 ms, inherent to any
relative-countdown re-arm scheme. Reported as measured, not smoothed over.
The interrupt sustained continuously across both windows with no stall and
no storm, which is the primary evidence re-arm-every-tick is correct;
the small rate bias is overhead, not a defect.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 22:14:52 -04:00
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src/

Hosted StarForth VM implementation (compiled by the root Makefile). Bare-metal kernel sources live in src/starkernel/; FORTH word implementations in src/word_source/; the test harness in src/test_runner/; platform shims in src/platform/.

Entry point / interpreter core

  • main.c — CLI entry point, VM init, DoE mode dispatch.
  • vm.c — interpreter loop, stacks, dictionary state (the central runtime file).
  • vm_api.c — external VM API implementation.
  • vm_bootstrap.c — VM bootstrap initialization.
  • vm_debug.c — debugging utilities.
  • vm_time.c — time-related VM operations.
  • vm_internal.h — internal-only declarations shared across the vm_*.c files, not part of the public include/vm_api.h surface.
  • repl.c — REPL read-eval-print loop.
  • cli.c — CLI argument parsing.
  • io.c — I/O operations.
  • log.c — logging infrastructure.

Memory / dictionary / blocks

  • memory_management.c — dictionary allocator.
  • dictionary_management.c — dictionary allocation and search.
  • dictionary_heat_optimization.c — Loop #1 execution-heat tracking.
  • word_registry.c — word registration system.
  • block_subsystem.c — logical→physical block mapper.
  • blkio_file.c, blkio_ram.c, blkio_factory.c — block I/O backends (file-backed, RAM-backed) and the factory that selects between them.
  • stack_management.c — stack operations.

Physics-driven adaptive runtime (7 feedback loops)

  • physics_runtime.c — main physics coordinator.
  • physics_hotwords_cache.c — Loop #1 hot-words caching.
  • physics_metadata.c — per-word metadata tracking.
  • physics_pipelining_metrics.c — Loop #4 word-transition prediction.
  • physics_execution_hooks.c — execution instrumentation.
  • rolling_window_of_truth.c — Loop #2 circular execution-history buffer.
  • inference_engine.c — Loops #5/#6, statistical inference (window-width, decay-slope).
  • ssm_jacquard.c — L8 Jacquard steady-state mode selector; consumes compudynamics.c for tuning-word/config lookups.
  • compudynamics.c — generic compudynamics module (cd_tuning_word(), cd_tuning_vm()); the score/UCB/reward/weight constants for the L8 adaptive table live here, not in ssm_jacquard.c.
  • heartbeat_export.c — heartbeat metrics export (CSV export function itself not yet implemented — see docs/working/architecture/heartbeat_csv_export.md).

Math / measurement

  • math_portable.c — portable math functions.
  • profiler.c — performance profiling.
  • doe_metrics.c — Design of Experiments metrics (2^7 factorial).

Any .bak file alongside a .c file here (doe_metrics.c.bak, inference_engine.c.bak, vm.c.bak) is a pre-edit backup left by a past maintenance script (see scripts/remove_loop_conditionals.sh), not a build input.