Robert Allan JamesandClaude Sonnet 5
bea8d7436a
double_word_d_plus(), double_word_d_minus(), and double_word_dnegate() (double_words.c) all cast through plain `unsigned long` for their carry/ borrow-detection arithmetic. On this aarch64 bare-metal cross-compile target, unsigned long is 32-bit (confirmed: sizeof(unsigned long)==4) -- amd64 and riscv64 both happen to have a 64-bit long, so the identical code only broke on aarch64. The low-cell arithmetic silently truncated to 32 bits, then widened back to cell_t via ordinary (non-sign-extending) conversion, producing a wrong result whenever the true 64-bit result was negative -- D. then correctly, faithfully reported DOUBLE-OVERFLOW on the resulting malformed double. vm.h already defines ucell_t for exactly this: same conditional as cell_t, guaranteed width-matched on every target. print_number_formatted() (format_words.c) already used it correctly; these three words didn't. Switched all three to ucell_t -- a one-word-class fix, no logic change. Verified: rebuilt and booted all three architectures clean. T19 (D+) on aarch64 now correctly prints -2, matching amd64/riscv64; T20 (DNEGATE) unaffected everywhere. Additional manual cases beyond the original exerciser, run live on aarch64 to specifically exercise the >32-bit-magnitude path the old bug depended on: D- (-5-3=-8), DNEGATE on 2^33 (8589934592 -> -8589934592), D+ crossing the same boundary (3+8589934592=8589934595) -- all correct. d_compare() (backing DMAX/DMIN/D</D=) has the identical latent pattern but is out of scope for this fix (not named in the request, never exercised by the campaign) -- left open, flagged in FABRIC-3.md. M*'s separate, universal-across-all-three-architectures DOUBLE-OVERFLOW bug is also untouched -- unrelated defect, not part of this fix. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EXieurDfDSsDFdnSyusuWo
capsules/
FORTH personality files loaded by the VM at boot. A capsule is an immutable, content-addressed payload; its XXHash64 hash is its identity. Any mutation changes the hash and the birth protocol rejects the image.
Key files
| File | Type | Purpose |
|---|---|---|
init.4th |
(m) MAMA_INIT |
Default Mama VM personality — loaded at LBN 2048 |
ACL.4th |
user | Word-level ACL system; self-activating at boot |
zuse.4th |
user | Bootstrap superuser; loaded by ACL.4th |
doe.4th |
user | DoE workload words (EXEC-DOE) — opt-in |
init-0.4th … init-9.4th |
(p) |
Numbered personality variants |
init-l8-*.4th |
(p) |
L8 Jacquard mode variants (stable/volatile/diverse/temporal/transition/omni) |
hermes/init.4th |
(p) |
Hermes baby VM personality |
artemis/init.4th |
(p) |
Artemis baby VM personality |
Block namespace
Block ranges are shared across all loaded capsules — collisions cause silent word-definition overwrites.
| Range | Owner |
|---|---|
| 2048–2099 | init.4th |
| 2100–2199 | doe.4th |
| 3000–3999 | workload capsules |
| 4000+ | user-defined (ACL.4th, zuse.4th, …) |
Each block is limited to 1024 bytes. Verify with wc -c before committing.
See also
experiments/bare_metal/README.md— DoE protocols and block namespace rulesdocs/03-architecture/word-acl/DESIGN.md— ACL system designtools/mkcapsule.c— assembles capsules intocapsule_generated.c- Project root