How can I reboot a crashed Linux target system?

The best way to reboot a Linux target system is from its desktop environment or with the reboot   command. If you can't do that because the Linux target system has crashed, you may still be able to safely reboot it using a magic SysRq key combination. TinyPilot can send the REISUB   key combination for you using a script.

Adding the "send-reisub" script

To add the "send-reisub" script, connect to your device over SSH and run the following snippet:

sudo mkdir -p /usr/bin/tinypilot-user-scripts && \
  sudo touch /usr/bin/tinypilot-user-scripts/send-reisub && \
  sudo chmod 755 /usr/bin/tinypilot-user-scripts && \
  sudo chmod 744 /usr/bin/tinypilot-user-scripts/send-reisub && \
  sudo tee /usr/bin/tinypilot-user-scripts/send-reisub > /dev/null << 'EOF'
#!/bin/bash

echo -ne "\x04\x00\x46\x15\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x04\x00\x46\x08\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x04\x00\x46\x0C\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x04\x00\x46\x16\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x04\x00\x46\x18\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x04\x00\x46\x05\x00\x00\x00\x00" > /dev/hidg0
echo -ne "\x00\x00\x00\x00\x00\x00\x00\x00" > /dev/hidg0
EOF

Using the "send-reisub" script

Once you've installed the "send-reisub" script, you can run it by opening the "Scripts" menu and clicking "send-reisub". The script will immediately send the relevant commands to the target computer, which should reboot after a short delay.

Removing the "send-reisub" script

If you no longer need to REISUB   key combination with "send-reisub", you can remove the script by connecting to your device over SSH and running the following command:

sudo rm /usr/bin/tinypilot-user-scripts/send-reisub