LithosAnanake/FABRIC-3.md

FABRIC-3.md — the Stadium, continued again

Status: Living working document, opened 2026-08-25 as the successor to FABRIC-2.md (now closed/archival — see its own header). This document does not repeat FABRIC-2.md's design argument or history; it restates only outcomes, with pointers back to the section that derived them. Read FABRIC.md for the original "why," FABRIC-2.md for everything derived through 2026-08-25, this document for what's left as of that date onward.

Provenance. Everything in Section A below is a full, non-sampled carry-forward of every open (- [ ]) item in FABRIC-2.md as of 2026-08-25 — 51 items, confirmed by grep -c '^- \[ \]' FABRIC-2.md, none dropped (Section A itself holds 49: the other 2, FABRIC-2.md §F.3's own two checkbox lines, were pure summaries cross-referencing items already listed individually elsewhere — 4.4s/1.11/4.3/§17.4 and 5.1/ACL-RWT re-measurement, both of which are carried forward as their own individual items above — not distinct content, confirmed by diffing item text programmatically before writing this document, not assumed). Extracted mechanically (a script pulling each checkbox item's own text, stopping at the first blank line rather than the next checkbox, to avoid pulling in unrelated already-resolved narrative that happened to sit between two open items in the source document) and spot-checked against the original. Item numbers/labels are carried forward unchanged, for traceability — this is not a renumbering or a re-prioritization. Section groupings match FABRIC-2.md's own (documentation debt, xHCI WRITE(10), Milestone 3–9 punch lists, etc.) — items are relocated, not reorganized.

How to use this document going forward. New findings, new punch-list items, and new decisions get added here, not to FABRIC-2.md. Follow the same discipline FABRIC-2.md §(intro) established for how work gets picked up, closed, and recorded.

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A. Carried forward from FABRIC-2.md (51 items, all still open as of 2026-08-25)

From FABRIC-2.md §A — Blocked or scoped, not started

• 1.11 — Dirty-event granularity. Leaning region-based. Blocked on item 4.3 — settled as part of the console migration, not speculatively before it. Refs (FABRIC.md): §17.5, §23.2, §23.4 #1.

• 4.3 — Console. Umbrella item; settles 1.11 as part of the work. Nearly everything under it (4.3.1–4.3.7f, 4.4–4.4ac) is done — the parent stays open only because 4.4s below is still blocked and nothing has formally closed the umbrella. Refs (FABRIC.md): §17.5, §27.

• 4.4s — (user) prompt segment. Scoped, blocked, not started. Extends 4.4's prompt format. Refs (FABRIC.md): §27.8, 4.4.

• 5.1 — Re-run the DoE on the new substrate. A green POST suite is not evidence that determinism holds under the Stadium migration — needs its own campaign. Not started.

From FABRIC-2.md §D — Design questions still genuinely open

• §17.4 — the framebuffer utility's internal heat/decay dynamics are undesigned. Explicitly "Open, deferred": not a Stadium patron, but what physics (if any) governs it internally was never designed. Not blocking anything. Blocked on item 1.11 specifically (dirty-event granularity), not "the framebuffer work" in general — see FABRIC-2.md §D's own 2026-08-13 refinement of this item before assuming it's ripe.

From FABRIC-2.md §E — Documentation debt

• ACL-RWT DoE overhead re-measurement. The measured overhead numbers in .claude/CLAUDE.md ("+0.0054%–+0.0088%") were all captured at -O0, before item 4.5 enabled real compiler optimization. Nobody has re-measured, or even confirmed the old and new numbers are comparable at all. Flagged in passing during item 4.5f, never formally scoped. Ruled 2026-08-19 (FABRIC-2.md §F.3): wait for Artemis to land before re-running — Artemis has since landed; this is now unblocked but still not started.

From FABRIC-2.md §J — Maintainability sweep (2026-08-18)

• docs/lithosananke/ROADMAP.md and M7.1.md — stale Branch: lithosananke (no such branch exists post-split), M7.1.md's "Status: Design Complete" (shipped and live, not just designed), ROADMAP.md's self-contradiction (M8 marked OBSOLETE in one place, still a live success criterion in another), and its stale "AHCI driver" claim for M9 (real implementation is virtio_blk.c) — not fixed, flagged.

• Top-level ROADMAP.md (StarForth-era, "Phase 0 Complete... Phase 1 Starting," dated 2025-12-14) — badly stale, no historical/superseded banner to warn a reader. Not fixed.

• docs/03-architecture/word-acl/DESIGN.md says ACL Phase 7 (LithosAnanke kernel parity) is still "remaining" — direct contradiction with .claude/CLAUDE.md, which states Phase 7 is independently verified complete. Not fixed.

• VM-FLEET-ATTRACTOR-DESIGN-20260705.md claims doe-campaign.4th is "broken and being superseded" — unverified against repeated successful L8-DOE runs (a different FORTH entry point; not confirmed either way).

• Isabelle/HOL: the pipeline-metrics model/C-struct mismatch this sweep surfaced — flagged in the .thy file itself, not independently tracked elsewhere, not fixed.

From FABRIC-2.md §X, Milestone 2 — USB hardware stack

• Decide and implement where the hotplug event surfaces to the rest of the kernel — likely a callback registered by whatever owns the home-blocks logic, not xHCI code calling into block_subsystem.c directly (matching the existing "kernel/Artemis decoupling boundary" pattern already documented in block_subsystem.c). Partially addressed by Milestone 2h's blkio_usb.c/connect-time attach wiring (FABRIC-2.md, 2026-08-25) — worth re-checking whether that closes this item outright before treating it as still fully open.

• Implement CBW/data/CSW for SCSI WRITE(10) — this is where the earlier "read/write, unquestionable" requirement actually gets satisfied. Still the single biggest functional gap in the xHCI driver — blocks writing to a real USB thumb drive at all (blkio_usb.c is read-only today specifically because of this).

• Implement basic error/stall recovery (CSW failure status, endpoint stall clear) — at minimum enough to not wedge the controller on a single bad transfer.

From FABRIC-2.md §X, Milestone 3 — Block subsystem extensions

• Implement the CA-signed-cert verification path (Milestone 6 dependency — the cert chain validator doesn't exist yet either).

• Implement the first-touch allocation function: given a verified identity pubkey and a requested block count, either read an existing range from the drive's map or claim a new one at g.total_user_lbn and write it back. (Single-block relocation itself — the mechanism this would allocate ranges for — is done: blk_subsys_relocate_block()/ RELOCATE-BLOCK, FABRIC-2.md, commit 36d832f. This item is about the identity→range allocation that decides what to relocate blocks into*, still unbuilt.)*

• Design the on-drive block-map format (Section U item 4) — what it records (block ranges claimed? individual block liveness? something else), how it's serialized.

• Implement writing the block-map to a drive.

• Implement reading/validating the block-map from a drive on insertion.

• Design the migration state machine (Section U item 5) — states, transition triggers. Session direction, 2026-08-25: ACL manages when to relocate (capacity pressure, or a compudynamics heat/cold signal); migration itself is expected to be rare, not routine. The physics_hotwords_cache.c-reuse question is settled differently than originally framed — see this document's new §B below (Stadium unification), which reframes block/word placement as a compudynamics.c-driven decision generically, not a physics_hotwords_cache.c (DictEntry*-hardcoded) reuse question specifically.

• Decide and implement unclean-removal handling (Section U's explicitly flagged open question — never answered) — at minimum, detect a mid-flush disconnect via Milestone 2e's disconnect signal and decide what state that leaves affected blocks in.

From FABRIC-2.md §X, Milestone 4 — Drive/credential security

• Design the home-blocks drive signature format (Section U item 7) — reusing CAPSULE_MAGIC_PACK's pattern (magic + version in a fixed header field) as the confirmed precedent, applied to a drive's reserved header block instead of a capsule.

• Implement the signature check, called before any write path touches a newly-inserted drive.

• Implement the warn-and-refuse behavior for blank/foreign/unrecognized media.

• Extend acl_pinned's one-way-ratchet mechanism (already exists, already proven, just needs applying) to gate zuse credential minting specifically — confirm whether this literally reuses the existing acl_pinned bit on some relevant DictEntry, or needs its own analogous one-way flag on the credential data itself (the credential isn't a dictionary word, so the existing bit may not directly apply — open question, not yet resolved).

From FABRIC-2.md §X, Milestone 5 — Console/VM key-match binding

• Settle the still-open question: reuse ACL-PIN/acl_allow directly, or build a separate key-matching primitive — ACL-PIN gates word execution specifically and nothing today gates console-session-to-VM ownership, so this decision needs to happen before any code gets written here.

• Design the key/lock data shape (what the console presents, what the VM carries, how they're compared).

• Wire drive insertion (Milestone 2e's hotplug signal, post-identity-authentication) to a call into capsule_birth_baby() (confirmed a real, callable, on-demand birth path already) to spin up or re-attach that identity's VM.

• Implement the actual attach/bind step — extending sk_repl_set_active_vm() (confirmed to exist, currently an unguarded raw pointer-set) with the key-match check from above, so a console can only bind to the one VM whose lock matches its key.

• Implement detach behavior on console disconnect or VM teardown.

From FABRIC-2.md §X, Milestone 6 — Kernel/capsule PKI signing chain

• Generate (offline, outside the kernel/repo entirely) the real root CA keypair — "stays unrevocable," never embedded, never loaded by any kernel code.

• Generate the "snakeoil" intermediate certificate, signed by that real root CA (this is a real CA-signed intermediate, not a self-signed/untrusted cert despite the name — "snakeoil" names its informal/private-project status).

• Embed the already-CA-signed snakeoil intermediate as a capsule blob at build time (mechanically proven already via the font-capsule precedent — no new embedding infrastructure needed, just a new payload). Bootstrapping resolved: no kernel-boot-time verification of a hardcoded CA public key is needed at all — trust is established once, at build time, by whoever holds the real root CA and produces the build.

• Add a signing step to the mkcapsule build tool (or a separate signing tool) that produces a signature alongside each capsule's existing xxHash64.

• Extend MANIFEST_AUTO.md's generation to add a signature-status column, matching the existing xxHash64 column's generation pattern.

• Implement magic-number-based content-type detection (Section U item 14) — a shared primitive, also usable for Milestone 4's foreign-drive check.

From FABRIC-2.md §X, Milestone 7 — Contributor capsules / trust tiers

• Create the capsules/contrib/ directory (mechanically trivial, matches existing subdirectory convention — the directory itself is not the work).

• Add a FLAG_CONTRIB bit to mkcapsule.c's flag system, assigned by path match (contrib/ prefix), same pattern as how init.4th already gets FLAG_MAMA_INIT.

• Decide and implement one of the four spitballed trust-tier directions (signature- authority tiers / block-namespace sandboxing / QEMU-vs-real-hardware conditional enforcement) — none chosen yet, this is a real decision point, not just an implementation task.

• If block-namespace sandboxing is chosen: extend mkcapsule's existing conflict- detection logic to also reject a contrib/-path capsule claiming blocks outside its reserved range.

From FABRIC-2.md §X, Milestone 8 — Bare-metal boot from physical USB

• Build a fresh starkernel.iso via make -f Makefile.starkernel ARCH=amd64 clean + the ISO-build step.
• Identify the exact block device path for the target USB drive on the host doing the flashing (lsblk/dmesg after insertion — care needed, wrong device = data loss).
• dd if=build/amd64/kernel/starkernel.iso of=/dev/sdX bs=4M status=progress (or equivalent) — confirm dd is the right tool for an El Torito ISO vs. needing isohybrid first (open question, not yet verified).
• Physically boot the real machine from the flashed drive (BIOS/UEFI boot-order menu, Secure Boot may need disabling — unknown until tried).
• Capture what happens with no serial-socket log available (real hardware has no qemu-serial-*.sock to socat into) — decide the observation method.
• Confirm POST reaches the same 1012/0/0 result on real hardware as every QEMU acceptance run.
• Confirm ok> prompt is reachable and a basic command (e.g. HEARTBEAT-TICKS@ .) works identically to QEMU.
• Document the result (pass/fail, and if fail, what diverged from QEMU) — first real external validation this project has ever had outside QEMU TCG emulation.

From FABRIC-2.md §X, Milestone 9 — Networking / capsule distribution server

• (Deferred) Revisit and punch-list this milestone once Milestone 7 closes, not before.

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B. Stadium unification — words/VMs/blocks/messages on the same engine

Raised 2026-08-25: "words are stadium patrons, VMs are patrons, blocks are patrons, messages are stadium patrons, all should be operated on by THE SAME ENGINE." Investigated before designing anything — the real state is more nuanced than "everything's a stub," verified via direct reads and git log, not assumed:

FABRIC.md §18.3 already decided the mapping (not invented here): blocks → MIGRATE, messages → DELIVER, ACLs → EXPIRE, words and VMs both → COOL. stadium_evict() (src/starkernel/vm/stadium.c) — real, tested infrastructure: bitmap tracking, pin/contains refusal, the Hera-patron-zero panic guard, heat-conservation back to the owner's reservoir on every reap — calls stadium_dispatch() for the actual payload action when a patron departs.

Per-behaviour status, as of 2026-08-25:

• MIGRATE (blocks) — zero consumer, genuinely stub (stadium_dispatch()'s case prints "MIGRATE (stub)" and returns). This session already built the real mechanical primitive it needs: blk_subsys_relocate_block()/RELOCATE-BLOCK (FABRIC-2.md, commit 36d832f), live-verified (redirect + content survive an abrupt kill and reboot) but never wired to stadium_dispatch() — it's a separate, parallel, already-working mechanism today, not routed through Stadium at all.
• COOL (words and VMs, same tag) — half real. Words are fully live, but via a separate, bespoke mechanism, stadium_word_dispatch() (stadium_words.c, item 4.1), wired directly into the real VM word-execution hot path (vm_core.c:690,885,896) — it does not go through the generic stadium_dispatch() switch at all. ONTOLOGY.md §IX claiming words are "not yet migrated" is itself stale documentation drift (same class of bug as the "glibc" misattribution corrected earlier this session — flagged as a small, separate fix below, not blocking). VM cooling has no evidence of ever being wired anywhere — still genuinely stub.
• DELIVER (Hermes messages) — FABRIC.md (~line 3452) records this explicitly as "Open, surfaced not resolved": Hermes's message/channel heat already integrates with Stadium's reservoir accounting (STADIUM-HEAT@, STADIUM-RES-PULL/PUSH), but which Hermes lifecycle event maps to DELIVER vs. EXPIRE was never decided, let alone wired. Real, substantial, Hermes-specific integration work.
• EXPIRE (ACL TTL expiry) — no evidence of any wiring anywhere; ACL.4th/ acl_recheck() has zero Stadium involvement today. Also substantial, separate work.

Why DELIVER/EXPIRE aren't being resolved in the same pass as MIGRATE: each is a full subsystem integration (Hermes lifecycle mapping; ACL-to-Stadium wiring where none has ever existed) in its own right — attempting all four stubs at once risks exactly the rushed, shipped-but-incomplete outcome the no-stubs rule (below) exists to prevent. MIGRATE gets resolved for real because this session already has a tested primitive underneath it; the other three become honest, explicit punch-list items instead of being touched speculatively.

Punch list:

• Wire STADIUM_BEHAVIOUR_MIGRATE in stadium_dispatch() to call blk_subsys_relocate_block() for real. Needs investigation first: what LBN pair does a block-patron's cell header actually carry at eviction time, and has anything ever admitted a block patron onto a Stadium cell in the first place? (Item 3.5's admission code in stadium.c/stadium_words.c needs tracing before wiring — if block-patron admission itself doesn't exist yet, that's a bigger prerequisite than just the dispatch stub, and should be reported back rather than built speculatively.)
• Scope VM-COOL: confirm whether capsule_vm_kill()/Tripod's existing VM lifecycle has any real hook point equivalent to stadium_evict(), or needs the same kind of admission work MIGRATE might need. Resolve for real if small; otherwise punch-list explicitly.
• DELIVER (Hermes) — scope as its own future item once MIGRATE/VM-COOL land; do not re-decide the DELIVER-vs-EXPIRE message/channel mapping here, FABRIC.md's own note already flags it as genuinely open, not casually assumable.
• EXPIRE (ACL) — scope as its own future item; ACL has never touched Stadium, this is new integration work, not a wire-up of something partially built.
• Fix ONTOLOGY.md §IX's "words (dictionary, warehouse-resident today, not yet migrated)" line — stale, words are fully migrated and live via stadium_word_dispatch(). Small, independent doc fix, not blocking any of the above.

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C. Standing rule: no stubs or TODOs, ever

Stated directly, 2026-08-25, after the stadium_dispatch() stub investigation above: "I've never allowed stubs before." Saved as a persistent memory (feedback_no_stubs_or_todos.md) so this applies across sessions, not just this one. Full statement: no stub function that prints a placeholder and returns, no TODO-and-move-on comment in place of real logic, in any language, ever committed as if it were finished work. Small, honest increments are still fine and encouraged — each increment just has to be a complete, real implementation of whatever slice it covers, never a placeholder for a later slice. A pre-existing stub found while working nearby (as here) gets flagged and resolved, not built on top of or left in place.