# USB09 isolated 32 KiB Controller A recovery pass

Status: complete
Type: evidence
Updated: 2026-08-01
Next Action: none; independent Pi and the complete broad-matrix sequence passed

Project Map: work/maps/map-smi-firmware-stabilization-and-qualification.md
Workpackage: work/wp/completed/wp-restore-broad-usb-compatibility-baseline.md
Checklist: work/checklists/checklist-stage-1b-four-drive-usb-compatibility-baseline.md
Incident: work/incidents/incident-usb09-false-write-failure-and-usb-compatibility-architecture-correction.md

## Candidate and baseline

- Controller A assembly `1751136`, hardware variant 0, J-Link `69664082`.
- Release S-record SHA-256:
  `82A277EEBBED0CC4FBDDCC848ACEFD43E706849803673C4920E7851FC2ACABB5`.
- Release ELF SHA-256:
  `6A2D8F79D72387311C83599663B192FCF764F53AB3E0926E3B917F3746B426CA`.
- Firmware source commit: `8fa1479b6b942f72f18ff4ed2cb1a5c73ddc2501`.
- USB09 had just passed its post-Windows-format Pi health baseline with label
  `USB09`, UUID `50D2-5C43`, serial `2512300955508200677718`, equal FATs,
  and a complete 8,053,063,680-byte direct read.

USB09 mounted on first insertion. Initial and pre-trigger captures reported:

- USB mounted/attached `1/1`, media generation 1;
- FileX handoff acceptance mask 15 and valid media pointer/identifier;
- application session state/status `2/0`;
- pending storage instance 0;
- system errors 0 and USB application errors 0;
- no VBUS, controller power, or reseat action.

## Controller and SD identity gate

- Complete raw CID: `035344535330384780976F0084018559`.
- CID available / driver status: `1 / 0`.
- Manufacturer: SanDisk/WD, MID `03`.
- OEM/application ID: `SD`.
- Product: `SS08G`, revision 8.0.
- Serial: `2540634244`.
- Manufacturing date: `2024-05`, valid.
- HPT media state/status/SSP status: `5 / 0 / 0`.
- HPT mismatch/lost/replace-media: `0 / 0 / 0`.

The initial USB capture, pre-trigger recheck, guarded trigger capture, and final
capture all reported valid representative-sector evidence. One intermediate
read-only HPT identity capture observed that flag as 0; no request was released
from that observation. The required guarded trigger immediately recaptured the
same CID, CID-valid 1, representative-sector-valid 1, and raw HPT state 6
before it released the export.

## Identical failure-range regression

Request 1 used filename `USB09_32K.csv` and the same HPT range as the failed
1 KiB case:

- entered/adjusted start: `301739760`;
- requested end: `302268900`;
- actual first/last: `301739760 / 302268900`;
- actual sequence range: `2–8541`;
- 8,750 records scanned and 8,540 selected;
- 8,540 healthy, 0 degraded, 0 snapshot gaps, 0 requested-range gaps;
- SD scan elapsed 11.16 seconds.

## Authoritative USB result

| Metric | Result |
| --- | ---: |
| Export state / reason | `4 / 0` (complete / none) |
| HPT / USB status | `0 / 0` |
| First USB failure status | `0` |
| Complete / published | `1 / 1` |
| USB phase | `14` (terminal publication complete) |
| Bytes requested | 429,175 |
| FileX write calls | 14 |
| Maximum FileX write | 32,768 bytes |
| Buffered flushes / capacity | `4 / 131,072` bytes |
| Row build | 1.27 seconds |
| File write | 0.81 seconds |
| File close | 0.00 seconds |
| Media flush | 0.02 seconds |
| Rename | 0.02 seconds |
| USB elapsed | 2.12 seconds |
| Total export elapsed | 13.30 seconds |

This directly resolves the controller-side failure discriminator. The 1 KiB
candidate attempted only 99,328 bytes in 97 calls, spent 70.69 seconds in
writes, then timed out during a 50.00-second close with raw `0x5C`. With the
isolated 32 KiB cap, the complete 429,175-byte publication uses 14 writes and
closes without measurable delay or error.

## Final controller state

After terminal publication, USB09 remained mounted and attached with the same
generation-1 valid application session and FileX media pointer. System errors
and USB application errors remained zero. Controller A's SD CID, detection,
representative-sector, HPT media, and zero-error gates remained valid. No
optional SCSI durability command, VBUS action, controller power action, or
specimen-specific behavior was used.

## Evidence location and remaining gate

Raw captures remain under the ignored directory:

`work/evidence/hpt-log-store-circular-mirror/controller-a/usb-32k-recovery-usb09-20260731/`

The controller-side incident regression passes. Independent Pi verification
subsequently passed equal FATs, filesystem state,
exact 429,175-byte size, all 8,540 sequential records, health/range metadata,
completion marker, absence of temporary artifacts, and kernel-error gates.
See `work/evidence/usb09-32k-recovery-pi-pass-20260731.md`.
