Reorganize source tree: kernel/, v3/, v4/ split and board infrastructure
Source tree reorganization: - Move StarForth v3 engine to v3/ (src/, include/, Makefile) - Move kernel to kernel/ (src/, include/, linker/, Makefile) - Create v4/ skeleton for F18-ISA golden model (DECOMPOSITION.md, JUSTIFICATION.md) - Move FABRIC-0..4.md to docs/fabric/ - Move ONTOLOGY.md and ROADMAP.md to docs/ Board infrastructure: - Add boards/ser5/, boards/raspi/, boards/milkv/, boards/zynq7020/ - Each board has board.mk (ISA, CPU flags, boot recipe) and README.md - Root Makefile becomes thin dispatcher: boot_image, all, clean, docs take TARGET - make boot_image TARGET=SER5|RASPI|MILKV builds one GPT/MBR image per board - ZYNQ7020 target exists but stops with clear error (ARMv7 port not built yet) - scripts/mkdiskimage.sh builds disk images for all boards Docs pipeline: - docs/book/ with LaTeX master (main.tex) and Makefile - pandoc converts Markdown to LaTeX at build time - Two Lua filters: table-widths.lua (wide tables wrap), code-breaks.lua (inline code breaks) - make docs builds single PDF (754 pages, 0 missing characters) - make docs TARGET=<board> adds board appendix - build/docs/<book|board>/meta.tex stamps git commit into PDF Bug fixes: - 42 include paths that only worked by accident now use correct relative paths - clang-18 hardcode replaced with configurable CC variable (fixed aarch64 build) - Pi 5: kernel_2712.img linked at 0x80000, .bss zeroed, memory reserved - Doxyfile, .clang-tidy, README.md, Kconfig paths updated Verified: - Hosted v3 build passes 1012 tests, 0 failures - SER5 image boots in QEMU (OVMF), POST passes, K exact (65536 = Q48_ONE) - Milk-V image boots in QEMU (OpenSBI + U-Boot + bootefi), POST passes - make clean TARGET=<board> removes only that board and its ISA objects - make all builds all boards, hosted v3, and docs in one run Co-authored-by: Junie <junie@jetbrains.com>
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# FABRIC-3.7.md — Phase 8 PKI: the elevation entrypoint
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**Status: OPEN — design only, no code written or authorized.**
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**CORRECTION (2026-09-22, before any code was written against this document): §2's central
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claim — that the old `SEND-ELEVATE-REQUEST` passed a raw cross-VM address into `ELEVATE-GRANT`'s
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`waddr` — is wrong.** Found while starting Part A's implementation: reading the actual deleted
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source (`git show 3e201c8^:capsules/common/messaging.4th`, block 5040) shows
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`SEND-ELEVATE-REQUEST` copied the target word's **name as literal character bytes** (via
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`ELEVATE-REQ-APPEND`'s `CMOVE`) into a scratch buffer, building the text `S" <name-text>" <pk0>
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<pk1> <pk2> <pk3> ELEVATE-GRANT`, and sent *that whole string* to Hera. When Hera's own
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interpreter runs `S" <name-text>"`, it allocates a fresh string **in Hera's own memory** and
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pushes Hera's own valid address — no numeric cross-VM address ever appears anywhere in this
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flow. §2 was written from `ELEVATE-GRANT`'s signature alone, assuming the caller forwarded a raw
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address, without first reading how the caller actually built its message. It didn't.
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**What is still real, much narrower than originally claimed:** if a future caller ever spliced
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*attacker-influenced* text into the name field without checking for an embedded `"` character,
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that could break out of the `S" ... "` literal early and inject arbitrary FORTH source, executed
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with Hera's privilege. That's an input-validation discipline question for whoever writes the new
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caller (validate: no embedded `"`, or just always use a compile-time-fixed literal name, never a
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runtime-supplied one) — not an architectural cross-VM-memory defect requiring the buffer/message
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redesign §3 originally called for. **§3's proposed mechanism (Hera-side fixed receive buffer,
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kernel-constructed integer-literal-only command) is not needed** — the original text-copy
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design was already safe against the bug as actually diagnosed. Kept below, struck through, for
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traceability, per this series' own rule against silently rewriting a prior state.
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Successor to
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`FABRIC-3.5.md`/`FABRIC-3.6.md` (both CLOSED/ARCHIVAL at `v2.1.0`) for exactly one topic: the
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Ed25519-challenge-response elevation entrypoint that `.claude/CLAUDE.md`'s ACL section names as
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Phase 8, the last open item in the word-level ACL system. This is a **new document**, not a
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reopening of `FABRIC-3.6.md` — that document's own close header says future fleet work gets its
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own document, and this is that.
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**Provenance.** Written 2026-09-22, immediately after `FABRIC-3.6.md`'s close, from a design
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conversation with Captain Bob about a security concern he raised directly: how to rebuild the
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elevation entrypoint that Phase 4's Category B strip left dangling, without reopening a hole.
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The design below was proposed, and Captain Bob asked for it in writing here rather than left
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only in session memory.
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---
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## 1. What's dangling, and why
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`FABRIC-3.6.md` Phase 4 (Category B strip, 2026-09-22) deleted `capsules/common/messaging.4th`
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after every FORTH-owned message type had been cut over to kernel-Hermes. One casualty was
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collateral, not intended: `SEND-ELEVATE-REQUEST` (`messaging.4th` block 5040) was the only
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caller of both `KH-ELEVATE-SEND` (`src/starkernel/repl.c`) and, transitively, `ELEVATE-GRANT`
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(`capsules/zuse-eligibility.4th`, blocks 4021–4022). All three still exist in the tree.
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`ELEVATE-GRANT` is still loaded at boot (`capsules/init.4th:18`). Nothing can call it any more.
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Captain Bob's decision at the time (`FABRIC-3.6.md`'s own Phase 4 entry): leave it unreachable,
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don't patch a caller back in as part of that strip. Phase 8 builds its own entrypoint instead of
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resuming this one. **This document is that entrypoint's design.**
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<details>
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<summary>Original §2/§3 (WRONG — see the correction at the top of this document; kept for
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traceability, not current design)</summary>
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### 2. The security hole in the old mechanism — found before any code was written
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`ELEVATE-GRANT`'s signature, unchanged since it was written:
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```
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ELEVATE-GRANT ( waddr wu pk0 pk1 pk2 pk3 -- )
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```
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`waddr`/`wu` are an address/length pair meant to point at the string naming the word to elevate.
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`pk0`–`pk3` are the caller's Ed25519 pubkey, packed 8 bytes per cell (`ELEVATE-PUBKEY-UNPACK`,
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`mama_forth_words.c`).
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**The old `SEND-ELEVATE-REQUEST` computed `waddr` in the *sending* VM's own address space, but
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`ELEVATE-GRANT` always executes on Hera** (`ELEVATE-GRANT always runs on Hera` — `repl.c`'s own
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comment on `KH-ELEVATE-SEND`, still there). A word's name string lives in the sending VM's
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memory. `ELEVATE-GRANT` dereferences `waddr` in Hera's memory. Those are not the same address
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space by construction — `vaddr_t` is per-VM.
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**Consequence:** whoever controls `waddr` controls what bytes `NAME>XT` reads and resolves as a
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word name, in Hera's dictionary, not the caller's. This is not "the string might be malformed" —
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it is a primitive for making Hera's own `ELEVATE-GRANT` grant `ACL-ALLOW!`/`ACL-TTL!` on
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*whatever dictionary entry the attacker's chosen `waddr` happens to land on*, regardless of what
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word name the caller claims to be requesting elevation for. A caller who can influence `waddr`
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at all — not forge a signature, not defeat `zuse_eligibility_is_member()`, just choose a number
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— has a privilege-escalation primitive against the fleet governor.
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This was never exploited (the entrypoint has had zero live callers since the file that called it
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was deleted), and is reported here as a design defect found by inspection, not a live incident.
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### 3. The fix: never cross an address, only ever cross bytes
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This project already solved the general version of this problem once, this same session
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(`FABRIC-3.6.md` tasks 3.8/3.9, the payload-aliasing fix): a kernel-Hermes message's payload
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must be **copied into the message's own storage**, never a pointer into the sender's memory that
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might be reused or freed before the receiver drains it. `SkHermesMessage.payload_buf`
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(`include/starkernel/vm/kernel_hermes.h:160`, `SK_HERMES_CHUNK_MAX_PAYLOAD` = 1024 bytes) is
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exactly that fix, already built, already proven on all three architectures.
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**The elevation entrypoint's hole is the same defect one level up: an address crossing a
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boundary it isn't valid on the other side of.** The fix generalizes directly:
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1. **Never send `waddr`/`wu` across the kernel-Hermes boundary.** Send the pubkey (32 bytes,
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already the right shape for `payload_buf`) and the target word's **name, as literal bytes**,
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copied inline into the message payload — not an address, the actual characters. This is
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already how `CONSOLE-CMD-EVENT`'s payload works (a command string's bytes, not a pointer to
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one), so this isn't a new pattern, it's applying the existing one to the one caller that
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still passed a raw address.
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2. **On receipt, kernel-Hermes's C drain-checkpoint copies those name bytes into a small,
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fixed, kernel-owned buffer that already lives in Hera's own VM memory** — a receive-side
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mirror of the existing send-side pattern (`g_kh_elevate_buf`, `repl.c:445`, is the
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already-built precedent for "a static buffer this mechanism owns"; this needs its Hera-side
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counterpart). The buffer's address is a compile-time constant, known to the kernel, never
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computed from anything the caller supplied.
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3. **The FORTH command handed to `vm_interpret()` on Hera references only that fixed buffer's
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address and length as plain integer literals.** Both are always kernel-controlled. Neither is
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ever derived from caller input. `ELEVATE-GRANT` itself does not change — same signature, same
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`zuse_eligibility_is_member()` check, same `ACL-ALLOW!`/`ACL-TTL!` grant. Policy logic stays
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in FORTH, per `ACL.4th`'s own rule (no new C primitive for policy) — this fix is entirely
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about how bytes get from one VM to another, not about who is allowed to grant what.
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**Why this closes the hole structurally, not by validation:** there is no string to sanitize and
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no address to bounds-check, because the interpreted command never contains anything an attacker
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touched except opaque data bytes that get copied, never dereferenced as a pointer, by the
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receiving side. The class of bug (cross-address-space pointer confusion) becomes impossible by
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construction, the same way `payload_buf` made use-after-free impossible by construction rather
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than by careful lifetime tracking.
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</details>
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## 2 (corrected). What the old mechanism actually did, and the one real gap in it
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Re-read from the actual deleted source (`git show 3e201c8^:capsules/common/messaging.4th`,
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blocks 5039–5040): `SEND-ELEVATE-REQUEST ( pk3 pk2 pk1 pk0 waddr wu -- )` used `waddr`/`wu` only
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to `CMOVE` the target word's **name bytes**, as text, into a scratch buffer
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(`ELEVATE-REQ-BUF`/`ELEVATE-REQ-APPEND`) it owned — building the literal string `S"
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<name-text>" <pk0> <pk1> <pk2> <pk3> ELEVATE-GRANT` entirely in the *sending* VM's own memory.
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Only that finished string — not `waddr` itself — went to `KH-ELEVATE-SEND` and across to Hera.
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When Hera's interpreter runs `S" <name-text>"`, Hera's own `S"` allocates a fresh string **in
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Hera's own memory** and pushes Hera's own valid address. `waddr`/`wu` never cross the VM
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boundary as numbers at any point — only as copied character content. There is no cross-VM
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pointer dereference anywhere in this flow.
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**The one real, much narrower gap:** the name text is spliced into `S" ... "` with no check for
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an embedded `"` character. If a future caller ever passed attacker-influenced text as the name
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(none ever did — the word had zero live callers), a `"` in the name would close the string
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literal early and let the rest of the name execute as raw FORTH source, with Hera's privilege.
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This is a caller-discipline / input-validation question, not an architectural defect: either
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always use a compile-time-fixed name literal at the call site (no runtime input, no risk at
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all), or validate for an embedded `"` before building the command if a name ever does need to
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come from something less trusted than the call site's own source code.
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**Net effect on Phase 8 v1's scope:** Part A, as originally conceived in §3 above, is not
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needed. If a `SEND-ELEVATE-REQUEST` replacement is ever built, it can follow the original
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text-copy design as-is, with the one-line `"`-check added if and only if the name is ever
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runtime-supplied rather than a fixed literal. No kernel-Hermes/`repl.c` changes required. Part B
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(`capsules/zuse.4th`, gating `ZUSE-ELIGIBILITY-ADD`) stands on its own, independently verified,
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unaffected by this correction.
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## 4. What Phase 8 actually needs to build
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Corrected per §2's re-read above. Concretely, when Phase 8 next picks this up:
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- If a caller into `ELEVATE-GRANT` is ever needed again, rebuild it close to the original
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`SEND-ELEVATE-REQUEST` shape (`ELEVATE-REQ-BUF`/`ELEVATE-REQ-APPEND`/text-copy into `S" ...
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"`) — it was already safe. Add the one-line embedded-`"` check only if the name is ever
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runtime-supplied rather than a call-site literal. No `kernel_hermes.c`/`kernel_hermes.h`/
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`repl.c` changes needed for this.
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- `ELEVATE-GRANT` unchanged either way.
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- **Part B is done** (`capsules/zuse.4th`, committed and three-arch verified this session,
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2026-09-22) — `ZUSE-ELIGIBILITY-ADD` denied by default, granted only inside `ACL-ZUSE-BOOT`'s
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authenticated branch. This closes the actual "grant yourself eligibility with no real drive at
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all" path — a real, independently-confirmed gap, unaffected by this correction.
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- **Defending against a cloned drive — settled, 2026-09-23: not going to happen, by design.**
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Today, WIREBIND/MINT trust whatever identity is stored on an attached thumbdrive with no
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challenge at all (confirmed by grep: no `ed25519_sign`/`ed25519_verify` call anywhere in
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`capsule_wirebind.c` or `capsule_mint.c`), and the private key seed itself is stored in
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plaintext on the drive, read in the same devblock as the pubkey/cert. **This is accepted, not
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a gap.** Captain Bob, directly: *"nothing like a pin or a password or secret code or any
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bullshit... Everybody has secrets. There's only the drive."* Physical possession of the drive
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is the entire, deliberate credential model — a byte-for-byte clone being equivalent to the
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real drive is the accepted design, not a defect to close. A PIN/passphrase second factor was
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built, live-tested on all three architectures, and fully reverted before commit
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(`/home/rajames/.claude/plans/jiggly-cuddling-stallman.md`, now marked rejected; memory
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`feedback_no_knowledge_factor_identity`) — **do not revisit a knowledge-factor approach here.**
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Any future work in this space needs a fundamentally different mechanism (not something typed
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and known) or stays an accepted limitation.
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- **Phase 8 v3, 2026-09-23 — done, a distinct and narrower concern from the item above.** The
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"accepted limitation" above is about a drive image copied *outside* StarshipOS entirely (e.g.
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imaged on an external computer) — that's still accepted, unchanged by this item. Captain Bob
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separately asked to close a narrower, different threat: **cloning a device's block content
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from *within* StarshipOS's own console**, using its own stock, unpinned words
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(`<src> BLOCK <dst> BUFFER 1024 MOVE`/`RELOCATE-BLOCK`). That's now closed — `MOVE`/`CMOVE`/
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`CMOVE>`/`RELOCATE-BLOCK` all refuse a same-VM, cross-device copy, verified live on all three
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architectures. See `/home/rajames/.claude/plans/jiggly-cuddling-stallman.md`'s "Phase 8 v3"
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section for the full design and verification record. The identity record itself
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(seed/pubkey/cert) was already unreachable from FORTH before this — this closes the one real
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gap the research found: ordinary block content, not the identity record.
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## 5. What this document is not
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Not a reopening of `FABRIC-3.6.md`, not a change to anything currently built, not an
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authorization to write code. Per this series' own convention: design here, execution gets its
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own document when the work actually starts, the same relationship `FABRIC-3.5.md` had to
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`FABRIC-3.6.md`.
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