Robert Allan JamesandClaude Sonnet 5
af267a52a6
blk_subsys_detach_device() (block_subsystem.c) walks the device chain, refuses removal of anything but the current tail (a mid-chain removal would corrupt every later slot's start_lbn -- this architecture's own doc already argues USB stays last specifically to avoid that), unlinks, shrinks total_user_lbn, closes and frees the slot. Discards rather than flushes dirty state -- the device is physically gone by the time this runs (PORTSC disconnect only). Trigger wiring mirrors the attach path: bot_msc_attached (set only once attach actually succeeds) gates a new bot_msc_detach_pending flag set at PORTSC disconnect (not Disable Slot completion, which is conditionally skipped and would miss concurrent connect/disconnect pairs), consumed in sk_repl_idle(). Advisor flagged the real hazard ahead of time: block_words.c's VM block window (blk_vm_lbn[]/blk_vm_cbuf[]) can go stale across a detach then a same-LBN re-attach, and suggested a pointer-identity re-check in blk_vm_load() as a minimal fix. That fix was implemented, then directly falsified by its own designed-for-this test: attach a blank device, read a block (populating the cache), detach, re-attach a device with distinct content at the identical LBN, read again -- served stale content from the first device. Root cause, confirmed live: glibc's allocator hands free(slot) straight back to the very next same-size calloc(), so the "fresh" and stale pointers were bitwise identical despite being two different devices. Fixed properly with a monotonic blk_subsys_epoch() counter (bumped on every attach/detach) checked by a new blk_vm_check_epoch() helper at the one choke point (blk_vm_find(), plus blk_vm_flush_all() which reads the same arrays directly) that covers every path touching the window cache -- unfooled by address reuse. Verified live with a new disk/usb-thumbdrive-test2.img fixture (distinct content from the existing blank test image): attach A, read (cache hit populated), detach, re-attach B at the same LBN, read again -- correctly ran a fresh device read and returned B's real content, not A's stale cached zeros. The failing pointer-comparison attempt's own capture log kept as evidence, not deleted. All three architectures re-verified clean. FABRIC-2.md Section X 2h marked complete -- enumeration through hot-detach all live and verified; only WRITE(10) (2g's own still-open item) remains unimplemented in the driver, not blocking anything here. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CXjAPTEKrgY2Mrk25KoLDn
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