Files
StarForth/src
Robert Allan JamesandClaude Sonnet 5 e10fb76fb2 xhci: fix Configure Endpoint completion drop under concurrent multi-device enumeration
Root cause of the FABRIC-3.md §IX.5 follow-on: with 9 devices attached
concurrently at boot (Zuse + 8 identities), only 1 of 9 ever completed
enumeration and reached blkio_usb: MSC device ready -- the other 8 produced
no error and no success, just silence.

xhci_poll_events()'s deferred per-slot dispatch loop submitted a Configure
Endpoint command (a Command Ring op) unconditionally for every slot with
that action pending in a single pass -- unlike every other Command Ring op
in this driver (Enable Slot, Address Device, Disable Slot), which is
correctly gated behind dev->connect_state == XHCI_CONN_IDLE before ever
submitting. With 2+ devices enumerating concurrently, this let multiple
Configure Endpoint commands sit outstanding on the Command Ring at once.
Their completion is correlated purely via the single shared
dev->connect_state field (== XHCI_CONN_AWAIT_CONFIGURE_ENDPOINT), not the
completion event's own Slot ID -- so whichever slot's completion happened
to land while connect_state still read AWAIT_CONFIGURE_ENDPOINT got
correctly chained into SET_CONFIG, and every other slot's completion
arrived after connect_state had already moved on, silently swallowed by
the handler's generic "unrelated command completion" catch-all. No error
path exists for this, which is why it produced total silence rather than
a diagnosable failure.

Root-caused live via temporary WARN-level diagnostic probes (written,
captured, and fully reverted per the project's own probe convention --
this commit contains only the functional fix and its explanatory comment,
no probe code) added at four points: the initial port scan, the connect
handler, the Command Completion Event handler, and the deferred dispatch
loop itself. The probes showed all 9 devices correctly completing Enable
Slot + Address Device (ruling out the connect-state queue as the cause,
the original hypothesis), then all 9 correctly submitting Configure
Endpoint and all 9 commands completing successfully in hardware (code=
SUCCESS, no errors logged) -- but only 1 of 9 ever got its next_action
chained to SET_CONFIG.

Fix: apply the same single-in-flight discipline this driver already uses
for every other Command Ring op. If the Ring isn't free when a slot's
Configure Endpoint action is due, put the action back on that slot instead
of submitting a second command onto a busy Ring -- the next tick's
dispatch pass retries it once the Ring frees up.

Verified live: booting Zuse + all 8 identity drives concurrently (9
devices, one per real xHCI port via the XHCI_PORTS fix from the previous
commit) now produces 9 "MSC device ready" lines and zero xHCI errors,
where it previously produced exactly 1. Three-arch clean qemu acceptance
(single Zuse device, the standard regression case) passed on amd64,
aarch64, and riscv64 -- no change in that baseline behavior.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014Ec88YKxxhZGG1RNnune78
2026-09-07 09:02:45 -04:00
..
2026-08-01 07:49:56 -04:00
2026-08-01 07:49:56 -04:00
2026-08-01 07:49:56 -04:00
2026-08-01 07:49:56 -04:00

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.