Playbook: storage, USB and ssh

scope: generic · severity: technique · confidence: proven · subsystem: boot

Evidence

taimen README.md status; docs/BUILD-RUNBOOK.md

Goal: a rootfs that mounts and a shell you can reach without hands.

Done when: ssh answers, survives a reboot, and tk_boot_id returns a value that changes exactly once per boot.

Order

1. Storage first. UFS/eMMC before anything else — without it there is no rootfs and every other question is unanswerable. Check the controller probed and the partitions enumerated.
2. USB gadget. The pmOS gadget gives you NCM networking plus ACM serial. This is the channel everything else depends on.
3. ssh. Then immediately do the one-time setup that makes the toolbox work: no-passwordless-sudo-disables-the-whole-toolbox.
4. Run porthole doctor. It checks the above and names what is missing.

The traps

• no-passwordless-sudo-disables-the-whole-toolbox — the “every tool is broken” report
• ssh-host-keys-change-every-boot — why the ssh flags are what they are, and the multiplexing rule that follows from it
• frozen-is-not-hung — ssh not answering is not the same as the device being down

Measure your numbers now

Time a cold boot to first ssh, and a warm reboot cycle. Put them in the profile as PORTHOLE_REBOOT_BUDGET_S. Until you have them, every boot verdict is a guess (wait-long-enough-before-calling-a-boot-failed).