Robert Allan JamesandClaude Sonnet 5
986d042aa7
Fourth stage of the preemptive context-switching plan, and the biggest. LithosAnanke now genuinely, continuously preempts between Hera, Hermes, and Artemis -- timer-driven, running live for the entire remainder of every boot once the Tripod fleet registers, not a bounded probe. A real design fork was resolved before writing code: the naive approach (the timer ISR calling Stage 2's sk_vm_context_switch() directly) is broken -- Stage 0's trap frame lives on whatever stack was active at interrupt time, and jumping to a different stack via Stage 2's own independent swap mid-handler would abandon that trap frame unresumed, guaranteed corruption on the first tick. Chose the safer of two named options: the ISR only ever sets a flag and returns completely normally through its own full epilogue; the actual switch happens moments later, via Stage 2's already-proven mechanism, at a safe cooperative checkpoint on the mainline (execute_colon_word()'s per-word dispatch loop, checked on literally every word, not throttled to the existing 256-word heartbeat-tuning cadence) -- confirmed with the user that word-level granularity is fine-grained enough given the eventual Zynq FPGA target where a word is a mnemonic. New capsule_vm_switch_signal.c/.h: a purpose-built run-readiness signal, deliberately separate from capsule_vm_physics.c's execution-heat engine (that one's own header documents itself as never touched from interrupt context, by design). Slot table sized with headroom (8) rather than hardcoded to today's 3 participants, so extending participation later is another register() call, not a redesign -- per direct request to leave room for swapping the participant set. Simple linear accumulate-then- threshold for this first cut; a fancier law can replace it later without touching the mechanism around it. heartbeat_tick() gains its one deliberate, documented amendment to this file's own top-half/bottom-half discipline -- the first time this codebase reaches into VM-scheduling state from real ISR context. Registration happens only after all three VMs are fully born, right before the REPL starts -- no critical-section protection yet against being switched away mid-birth-setup. Known, flagged rough edge (not reconciled this pass): MSG-TICK's own idle-pump and this new mechanism can still independently move control between the same VMs; not observed to interact badly in verification, but not fully unified either. Verified interactively at the console on all 3 architectures with continuous background preemption running throughout -- amd64 computed `1 1 + .` -> 2, aarch64 computed `1 1 + dup DUP * . CR` -> 4, both correct, REPL fully responsive, zero fault indicators over sustained runtime. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016UNhH1mhi52i6Qihh7ZV5S
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.