Chains off the device descriptor request via a new deferred-action mechanism on xhci_dev_t (next_action/next_action_slot_id/next_action_length): a short 9-byte Configuration descriptor read learns wTotalLength, then a full read retrieves Config+Interface+Endpoint descriptors, walked for the Interface descriptor to confirm bInterfaceClass/SubClass/Protocol == Mass Storage/ SCSI/Bulk-Only Transport. The deferral exists because ringing the next doorbell synchronously inside xhci_poll_events()'s event-processing loop -- before the current event's ERDP write -- hung the guest outright (confirmed live via checkpoint logging, amd64). Fixed by moving the actual control-transfer submission to a small dispatch at the end of xhci_poll_events(), after ERDP is updated. A debug hack that shipped mid-session (forcing a repeated 9-byte read instead of chaining into the real 44-byte length, to isolate whether the hang was doorbell-ordering or length-specific) has been reverted: restored the real length and re-verified live. The doorbell-ordering fix was the whole story -- the 44-byte read completes cleanly. Verified live via QMP hotplug, all three architectures, byte-identical results: wTotalLength=0x2c, bInterfaceClass=0x08, bInterfaceSubClass=0x06, bInterfaceProtocol=0x50 -- confirmed Mass Storage/SCSI/BOT. Disconnect confirmed clean on every arch, no wedge. FABRIC-2.md Section X Milestone 2f updated with the full writeup. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QPfdtaXs9ay1nbwuMnrscu
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