Introduces src/starkernel/heartbeat.c as the shared top/bottom-half implementation of heartbeat_init/tick/service/ticks/trust/state, replacing the per-architecture duplicates in amd64/riscv64/aarch64 timer.c. Each arch's timer.c now contributes only heartbeat_read_counter() (rdtsc / rdtime / CNTPCT_EL0). Per the GAP-A1 ruling the top half stays counter+ latch only; heartbeat_service() (called every REPL idle iteration, unconditionally per FABRIC.md's fidelity note) does the window/variance/ trust work outside interrupt context. vm_tick()'s call sites are unchanged -- the engine still runs on the virtual tick. Per FABRIC.md §26 (ruled 2026-08-03): wires Loop #7's execution-derived stable/volatile signal into the physical re-arm period. vm_runtime.c's existing Loop #7 site now calls heartbeat_set_adaptive_period_ns() with tick_target_ns ratio-rescaled onto a 10ms kernel base (not the hosted 10us HEARTBEAT_TICK_NS -- see §26.3 for the scale mismatch). Each architecture's re-arm function (apic_timer_rearm() on amd64/aarch64, riscv64_timer_rearm()) now converts heartbeat_next_period_ns() to its own raw counter units instead of a fixed constant; amd64 gained a rearm function it didn't previously need, since periodic-mode auto-reload never required one before this item. Verified: all three architectures build with no new warnings and boot cleanly to ok> with dict_hash=0x3d4e1daf289da94f, unchanged from the pre-change baseline -- no regression. Verified NOT achieved: live re-arm period variation under load. A temporary diagnostic (added and reverted) confirmed Loop #7 never actually fired during a live QEMU session -- a synthetic word-execution loop drove ~6,500 executions, past the 1000-tick inference frequency, without tripping vm_tick_inference_engine()'s pre-existing !vm->rolling_window.is_warm gate. That gate predates this item and was not investigated -- out of scope. FABRIC.md's Done-when is amended to record this honestly rather than claim it. Punch list §25 item 0.8 complete (per amended, weaker acceptance -- see the item's own annotation). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
include/
Public headers for the hosted StarForth VM (src/). Kernel-only headers
live under include/starkernel/.
Core VM
vm.h— theVMstruct and all core types (DictEntry,DictPhysics, stacks, dictionary state); the central header most other files include.vm_api.h— external VM API surface.vm_host.h,vm_debug.h,startup.h,version.h— host integration, debug utilities, startup sequencing, version string.cli.h,repl.h,io.h,log.h— CLI parsing, REPL loop, I/O, logging.word_registry.h— word registration system shared by everysrc/word_source/*.cfile.compudynamics.h— the generic compudynamics module: tuning-word/config lookups (cd_tuning_word(),cd_tuning_vm()) consumed byssm_jacquard.c.
Memory / blocks
memory_management.h,dictionary_management.h— dictionary allocator and search.block_subsystem.h,blkcfg.h,blkio.h,blkio_factory.h— logical→ physical block mapper and pluggable block I/O backends (file/RAM).platform_alloc.h,platform_lock.h,platform_time.h— platform abstraction shims (hosted vs. kernel allocation/locking/timing).
Physics-driven adaptive runtime (7 feedback loops)
physics_runtime.h— main physics coordinator.physics_hotwords_cache.h— Loop #1, execution-heat hot-words cache.physics_metadata.h— per-wordDictPhysicsmetadata tracking.physics_pipelining_metrics.h— Loop #4, word-transition prediction.physics_execution_hooks.h— execution instrumentation hook points.rolling_window_of_truth.h,rolling_window_knobs.h— Loop #2 circular execution-history buffer and its tuning knobs.inference_engine.h— Loops #5/#6, window-width and decay-slope statistical inference.dictionary_heat_optimization.h— Loop #1 heat counters.ssm_jacquard.h— L8 Jacquard steady-state mode selector.doe_metrics.h— Design of Experiments (2^7 factorial) metrics.profiler.h— performance profiling hooks.
Arithmetic / codegen
q48_16.h— Q48.16 deterministic fixed-point arithmetic (used instead of IEEE-754 float specifically to keep cross-architecture behavior bit-identical).math_portable.h— portable math helpers.arch_detect.h,starforth_config.h— architecture detection and the build-flag fallback-default layer (used when a.cfile is compiled by hand withoutmake).vm_asm_opt.h,vm_asm_opt_arm64.h,vm_asm_opt_riscv64.h,vm_inner_interp_asm.h,vm_inner_interp_arm64.h,vm_inner_interp_riscv64.h— per-architecture assembler-optimized inner interpreter (USE_ASM_OPT=1).
See include/starkernel/README.md for the bare-metal kernel headers.