DeckDoc Rescue

DeckDoc Rescue: bootable outside-OS diagnostics

DeckDoc Rescue is an alpha design for diagnosing a Deck independently of its installed OS. It boots from removable media through the firmware boot manager, captures live hardware state, and attempts to read installed SteamOS journals without mounting or repairing the internal disk.

It is not a Valve recovery image. It does not repair, re-image, factory-reset, unlock encrypted data, run fsck, mount internal filesystems, change EFI entries, flash firmware, or write the installed disk.

Why boot outside the installed OS

• separate “installed SteamOS is broken” from “hardware also fails in another environment”;
• recover previous-boot logs after a boot loop or black startup;
• inspect NVMe SMART, enumeration, USB-C/dock, display, thermal, power, and input presence even when Game Mode cannot start;
• compare BIOS/recovery/live behavior with the installed system before destructive recovery.

Booting another OS changes the kernel and drivers. A device working in Rescue strongly argues against total hardware absence, but does not prove the installed driver/config root cause. A device missing in one generic rescue kernel can also mean that kernel lacks Steam Deck support.

Current portable collector

From a compatible Linux rescue environment:

sudo ./bootprobe/deckdoc-rescue-collect.sh \
  --installed-disk /dev/nvme0n1 \
  --output-dir /path/to/removable-media

The collector creates a private archive with live PCI/USB/block/Type-C/PD/DRM/network/thermal/power state, rescue-boot journal, NVMe health, EFI boot entries, and installed boot indexes/current/previous journals where systemd can dissect the image. journalctl --image= is the documented image reader; the collector never mounts the disk. See systemd journalctl.

If the installed image cannot be dissected, the report says inaccessible. It must not silently remount or repair it. Encrypted or unusual layouts require a separate, explicit evidence-preserving workflow.

Alpha image builder

bootprobe/build-rescue-image.sh builds an ArchISO development image on an Arch Linux build host with the official archiso package. Arch's mkarchiso creates UEFI-capable live images and can sign artifacts, but this project does not yet ship a signed release.

Release gates:

1. pin and record every package/build input;
2. make the image reproducible and publish checksums/signatures;
3. boot-test Jupiter LCD and Galileo OLED, internal NVMe untouched;
4. validate Wi-Fi, docked Ethernet, USB storage, display, SMART, journal image reading, and shutdown;
5. threat-model remote access and redaction;
6. document safe image-writing with exact target verification.

Use Valve's current SteamOS recovery instructions for firmware boot and official recovery workflows. Do not confuse or replace those recovery actions with DeckDoc evidence collection.

Remote control and export

Docked Ethernet is the default remote transport. A release image should accept only an explicitly supplied SSH public key or one-time authenticated setup; it must not ship a default password or an unauthenticated web server. Reports remain local unless the user explicitly transfers them.

Direct USB-C networking is optional future work. Linux USB gadget mode requires a real USB Device Controller plus configfs/libcomposite support; connector shape alone is insufficient. The image must verify /sys/class/udc and kernel capabilities before offering it. See the kernel USB gadget documentation.

Hardware boundary

Persistence in BIOS, Valve recovery, and DeckDoc Rescue with known-good external power/cables raises hardware suspicion. Only Valve/service diagnosis, qualified electrical testing, or replacement of the isolated component resolving a controlled reproduction confirms hardware failure.