Robert Allan JamesandClaude Sonnet 5
57ac3fc304
Second stage of the preemptive context-switching plan. Every VM (Hera, every capsule_birth_baby()-born VM including WIREBIND identities) now gets its own dedicated 2 MiB native C stack at birth -- but nothing runs on it yet, that's Stage 2. Pure allocation-machinery proof. Design correction made before writing code: the plan called for cloning sk_vm_arena_alloc()'s guard-page pattern, but that pattern turns out to be Mama-only -- host_services.c's kernel_alloc() gives every baby VM a plain kmalloc() block for its dictionary arena, not a real guarded PMM allocation. Stacks get the real treatment instead (new sk_vm_native_stack_alloc()/_free() in arena.c): independent pmm_alloc_contiguous() + guard pages for every VM without exception, no singleton, no kmalloc fallback -- a stack overflow is exactly the failure mode guard pages exist for, and a corrupted stack could corrupt whatever saved context Stage 2 trusts. 2 MiB size matches this project's own established kernel-stack convention (g_kernel_stack/g_rpi5_native_stack), not a guess -- that one shared 2 MiB stack today already carries all VMs' combined nested VM-EXEC recursion. Three new VM struct fields, freed in vm_cleanup() alongside the existing call_stack free. Allocation failure is non-fatal to birth. All 3 architectures re-verified clean boot to ok>, no native-stack allocation failures for any Tripod-fleet VM. 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