Robert Allan JamesandClaude Sonnet 5
15672ce17c
First stage of the preemptive context-switching plan (see ~/.claude/plans/logical-snuggling-bear.md). Pure foundation work -- every arch's ISR now saves the full register set on interrupt entry, so a trap frame is in principle sufficient to resume execution anywhere it was taken. No FORTH-visible behavior changes. amd64: added FXSAVE/FXRSTOR, closing a genuine pre-existing correctness gap (not just future-preemption prep) -- confirmed live double-precision FP code reachable from ordinary interpreter dispatch (vm_runtime.c Loop #5/#6), and the ISR previously saved zero FP/SSE state. rbp repurposed as a fixed anchor so the 16-byte-aligned FXSAVE area can be carved out of an unpredictably-aligned rsp without disturbing existing argument reads. aarch64: extended the trap frame 672->800 bytes, adding v8-v15 (AAPCS64 callee-saved, previously excluded on call-site-only reasoning that doesn't hold for an async trap). riscv64: extended the trap frame 320->512 bytes, adding s0-s11 and fs0-fs11 (the latter still correctly gated behind sstatus.FS != Off). All 3 architectures re-verified clean boot to ok> under the new frames -- amd64 through hundreds of timer ticks with FXSAVE/FXRSTOR live on every interrupt, aarch64 through 987 ticks, riscv64 clean on the now-larger FS-conditional block. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016UNhH1mhi52i6Qihh7ZV5S
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 |
workload-0.4th … workload-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