Set Target Platform

Overview

This skill is the switcher side of the target-platform contract in ../../context/target-platform-contract.md. It only edits target-platform/active_target.yml; it never authors a new profile YAML. To author a new profile, use the sibling skill jetson-init-target.

Single output: target-platform/active_target.yml updated to point at the user's chosen existing profile.

When to invoke

• The user asks to switch / change / activate a different target platform among profiles that already exist.
• A downstream skill refused with "no active target" and target-platform/ already contains one or more profile YAMLs.
• The user names a target by filename or product, and that profile YAML is already on disk.

If target-platform/ is missing, empty, or contains only active_target.yml, stop and tell the user to run jetson-init-target first.

Procedure

Survey the profiles directory

1. Read target-platform/active_target.yml (treat a missing file as active: NA for the purposes of this skill — the file will be created in the "Update the active pointer" step if needed, preserving the template header).
2. List target-platform/*.yaml, excluding active_target.yml itself.

Situation	Action
No profile YAMLs exist	Refuse. Tell the user to run jetson-init-target to author one.
Exactly one profile, already active	Tell the user it is already active; no change needed. Stop.
Exactly one profile, not active	Confirm with the user, then jump to the "Update the active pointer" step with that profile selected.
Multiple profiles	Proceed to the "Show the list" step.

Show the list

Print the profiles in alphabetical order, numbered. Mark the current active selection with (active) so the user knows what they're switching from. For each profile, parse its YAML and show a one-line summary so the user can identify it without opening files: the reference_devkit.name (or custom_carrier.name if present) plus the flash_config.

Sample shape:

Profiles in target-platform/:
   1) acme-vision-x1.yaml          — Acme Vision X1 (custom carrier on AGX Thor T5000) — acme-vision-x1.conf
   2) jetson-agx-orin-32gb.yaml    — Jetson AGX Orin 32GB                              — jetson-agx-orin-devkit.conf
   3) jetson-agx-thor-devkit.yaml  — Jetson AGX Thor T5000                             — jetson-agx-thor-devkit.conf  (active)
   4) jetson-orin-nano-8gb.yaml    — Jetson Orin Nano 8GB                              — jetson-orin-nano-devkit.conf

If a profile YAML fails to parse or is missing the expected fields, show the bare filename with a (unparseable — fix or remove) marker and skip to the next; do not refuse the whole skill over one bad file.

Prompt for selection

Prompt:

Pick a number, the bare filename, the product name (substring match), or cancel.

Resolve to a single profile filename. If the user picks the currently active profile, tell them so and stop without rewriting the pointer. If ambiguous, list candidates and ask again.

Update the active pointer

Edit target-platform/active_target.yml:

• Set active: <chosen-filename>.yaml.
• Preserve the header comment block verbatim — only modify the active: line.
• If the file does not exist (it can be missing if the user hand-set up target-platform/ without the bootstrap step), create it from ../../references/active_target_template.yaml and then set active:.

Confirm

Print a summary: the previous active value, the new active value, the chosen profile's reference_devkit.name (and custom_carrier.name if present), and a reminder that downstream skills (jetson-customize-clocks, jetson-customize-nvpmodel, jetson-customize-fan, jetson-optimize-memory) will now resolve to this target.

If a downstream skill triggered this run, tell the user to re-issue their original request; do not silently re-trigger it.

Prerequisites

• target-platform/ exists and contains at least one *.yaml profile (excluding active_target.yml).
• target-platform/active_target.yml is present, or the template at ../../references/active_target_template.yaml is available so this skill can recreate the pointer.

Limitations

• Edits only the active: line in active_target.yml; never writes profile YAMLs.
• Refuses when no profile YAMLs exist — routes the user to jetson-init-target instead.
• Does not resolve fuzzy product names beyond simple substring match; ambiguous selections are re-prompted.

Troubleshooting

• "no profiles found" refusal — the directory has no *.yaml other than the pointer; run /jetson-init-target first.
• Pointer rewritten to a missing profile — should not happen because the chosen filename is verified before writing; if seen, hand-edit active_target.yml back to a valid filename or rerun with the right selection.
• Active pointer reads NA — legitimate "no selection" state; pick any listed profile and the pointer will be set.

Gotchas

• No authoring here. If the user names a target whose profile YAML is not on disk, refuse and route them to jetson-init-target. Do not silently fall through to authoring.
• Don't edit active_target.yml to point at a missing profile. Verify the chosen filename exists in target-platform/ before writing.
• Preserve active_target.yml's comment block when editing — only the active: line should change.
• Exclude active_target.yml from the profile list. It lives in the same directory but is the pointer, not a profile.
• active: NA is the legitimate "no selection" state. Treat it the same as a fresh pointer — don't refuse, just show the list and let the user pick.
• One-profile shortcut. If only one profile exists, do not skip user confirmation — still confirm before flipping the pointer.

References

• ../../context/target-platform-contract.md — the contract this skill writes to.
• ../../references/active_target_template.yaml — schema starter for the active-target pointer (used to recreate it if the file is missing).
• ../jetson-init-target/SKILL.md — sibling skill: author a new profile YAML.