CommentStreams:5711125217364fdf6de9d9a7bf1553fd

This script stopped working with Trixie, so I spent the day rewriting the shutdown portion so that it's usable going forward. Enjoy!

1. 1. 1. X-C1 Safe Power-Off (xoff)

1. What this does (by design)
2. • xoff → clean Linux shutdown
3. • All filesystems unmounted
4. • Then hardware power is cut via X-C1 GPIO pulse
5. • Board stays off (manual power-on required)
6. • Reboot remains safe (no power cut)

1. Prerequisites
2. • Raspberry Pi with X-C1 board attached
3. • Raspberry Pi OS (Bullseye / Bookworm / Trixie)
4. • GPIO27 wired to X-C1 soft power-cut input (default)
5. • Root filesystem on ext4 (standard)

1. 1. Step 1 — Install required packages

sudo apt update sudo apt install -y gpiod

1. Verify GPIO access:

gpioinfo -c gpiochip0 | grep GPIO27

1. You should see: "line 27: "GPIO27" input"

1. 1. Step 2 — Create the hardware power-cut script
2. This script only triggers the X-C1 power cut. It does not shut down Linux.

sudo tee /usr/local/sbin/xc1-powercut.sh > /dev/null <<'EOF'

1. !/usr/bin/env bash

set -euo pipefail

1. Pulse GPIO27 HIGH briefly to trigger X-C1 hard power cut

/usr/bin/gpioset -c gpiochip0 -p 100ms 27=1 EOF

sudo chmod 0755 /usr/local/sbin/xc1-powercut.sh

1. 1. Step 3 — Create the systemd shutdown unit
2. This ensures the GPIO pulse fires after all filesystems are unmounted, but only on poweroff, not reboot.

sudo tee /etc/systemd/system/xc1-cutpower.service > /dev/null <<'EOF' [Unit] Description=X-C1: cut power at end of poweroff (after unmount) DefaultDependencies=no After=umount.target Before=systemd-poweroff.service

[Service] Type=oneshot ExecStart=/bin/sh -c 'sync; sleep 0.2; /usr/local/sbin/xc1-powercut.sh' TimeoutStartSec=5

[Install] WantedBy=poweroff.target EOF

1. Activate it:

sudo systemctl daemon-reload sudo systemctl enable xc1-cutpower.service

1. Confirm attachment:

systemctl show -p After -p Before xc1-cutpower.service systemctl list-dependencies --plain poweroff.target | grep xc1 systemctl list-dependencies --plain reboot.target | grep xc1 || echo "not attached to reboot"

1. Expected: Attached to poweroff.target, Not attached to reboot.target

1. 1. Step 4 — Install the xoff command
2. We deliberately avoid shell aliases so this works consistently across SSH, scripts, and non-interactive shells

sudo tee /usr/local/bin/xoff > /dev/null <<'EOF'

1. !/usr/bin/env bash

exec sudo systemctl poweroff EOF

sudo chmod 0755 /usr/local/bin/xoff

1. If you previously used an alias, remove it:

unalias xoff 2>/dev/null || true sed -i '/^alias xoff=/d' ~/.bashrc

1. Verify:

type -a xoff

1. Expected: xoff is /usr/local/bin/xoff

1. 1. Step 5 — Test sequence

1. Test poweroff (expected to cut power)

xoff

1. Expected behavior: System shuts down cleanly, Power is cut, Board stays off, Manual power-on required

1. Test reboot (must NOT cut power)

sudo reboot

1. Expected behavior: Normal reboot, Power remains applied, No manual intervention required

1. 1. 1. Summary

1. You now have:
2. • A clean, modern, maintainable X-C1 power-off implementation
3. • No deprecated GPIO sysfs
4. • No vendor scripts
5. • No reboot hazards
6. • No disk corruption risk