Interactive serial module by llogen · Pull Request #282 · BlindspotSoftware/dutctl

llogen · 2026-02-18T09:33:51Z

Bidirectional serial console to the DUT. Resolves #121 and #119.

Extends the serial module — which already streams output (monitor) and runs scripted expect/send steps on main — with a live, hand-driven console, and makes sessions resilient to the device dropping out.

Client (`cmds/dutctl`)

Switches the terminal to raw mode for an interactive run, so every keystroke — including Ctrl-C, Ctrl-D and Ctrl-Z — streams straight to the DUT instead of being handled locally. Quit the session with Ctrl-A then x.

Raw mode is armed lazily: only when the run is interactive (invoked without arguments) and the agent actually streams console output — so scripted and one-shot commands (power, flash) leave the terminal untouched. Implemented for Linux and macOS; other platforms (incl. Windows) build with a no-op, line-buffered fallback.

Module (`pkg/module/serial`)

Interactive mode (-i) — bridges the client console to the serial port in both directions, until the session is cancelled or -t elapses.
Auto-reconnect (Reconnect serial device automatically #119) — if the serial device disappears mid-session (e.g. an FTDI chip that powers down with the DUT), the module waits for it to reappear and reconnects instead of ending the run. Active in interactive, monitor and expect modes.

Agent (`internal/dutagent`)

Closes the module's stdin channel on session teardown, so a module blocked reading client input (like the serial console) unblocks via EOF and the command returns cleanly instead of hanging.

The serial module gains three modes - interactive pass-through, expect (wait for a regex then exit) and expect-send pairs that auto-reply to prompts - and strips non-SGR terminal sequences from DUT output so they cannot corrupt the client terminal. If the serial device disappears mid-session (e.g. an FTDI chip that powers down with the DUT) it waits for the device to reappear and reconnects automatically. (#119) Signed-off-by: llogen <christoph.lange@blindspot.software>

The agent now closes the module stdin channel during session teardown, so a module blocked reading client input (such as the serial console) unblocks via EOF and the command returns instead of hanging. Signed-off-by: llogen <christoph.lange@blindspot.software>

The client now switches the terminal to raw mode during a run and forwards every keystroke - including Ctrl-C, Ctrl-D and Ctrl-Z - straight to the DUT. Press Ctrl-A then x to quit the session. Raw mode is build-tagged for Linux and macOS, with a no-op fallback on other platforms so the client still builds everywhere. (#121) Signed-off-by: llogen <christoph.lange@blindspot.software>

llogen requested a review from Copilot February 18, 2026 09:33

Copilot started reviewing on behalf of llogen February 18, 2026 09:34 View session