A new use for Lenovo onekey recovery key

I do not have an idea how to use this button with GRUB, but there are at least two approaches how to make it usable within Ubuntu. For example if you want to bind the reboot command to that button you could: (1) create acpi event or (2) create custom shortcut.

Create acpi event and bind the reboot command to it

First you need to use acpi_listen and catch the event when the button is pressed. Just execute the command acpi_listen and press the button:

$ acpi_listen 
button/prog1 PROG1 00000080 00000000 K

• In the above example button/prog1 PROG1 00000080 00000000 K is the event on my system when I press the discussed button.

Then you should crate a file that will handle this event. The file must be located in the directory /etc/acpi/events/. Call it for example reboot. The content of /etc/acpi/events/reboot should be similar as:

# /etc/acpi/events/reboot
# This will reboot the system
event=button/prog1 PROG1 00000080 00000000 K
action=systemctl reboot

Save the file and restart the acpi daemon:

sudo systemctl restart acpid.service

IMO this is the most simple method. This should work also when the user is not logged in. Here are few references where you can find additional information and examples:

• How do I disable the touchpad when the lid is twisted or closed?
• Ubuntu 17.10 laptop doesn't suspend on lid close
• Battery drains down even after shut down

Create acpi event and bind a script to it

We can add an insurance in case you press the button accidentally. Here we will create a script that will use a tmp file as flag and counter as it is described here. Thus the system reboot will be performed when you press the button three times.

1. Modify /etc/acpi/events/reboot in this way:

   # /etc/acpi/events/reboot
   # This will reboot the system
   event=button/prog1 PROG1 00000080 00000000 K
   action=/etc/acpi/reboot.sh
   

   Restart the acpi daemon:

   sudo systemctl restart acpid.service
   

2. Create the script /etc/acpi/reboot.sh and put the following lines as its content:

   #!/bin/bash  
   FLAG_FILE="/tmp/sysyem_reboot_flag"
   
   # If the file exists and it is older than 30 seconds, then reset the counter 
   # Else If the file doesn't exist or its 'value' is less than 2, then increment
   # Else (when the file exists, its value is equal or greater than 2, and its age is less than 30 seconds) reboot the system 
   
   if [ -f "${FLAG_FILE}" ] && [[ $(find "${FLAG_FILE}" -newermt '-30 sec') == '' ]]; then
       echo '1' > "$FLAG_FILE"
   elif [ ! -f "${FLAG_FILE}" ] || (( $(cat "$FLAG_FILE") < 2 )); then
       touch "$FLAG_FILE"
       NEW_VALUE=$(( $(cat "$FLAG_FILE") + 1)) && echo "$NEW_VALUE" > "$FLAG_FILE"
   else
       systemctl reboot
   fi
   

   Make it executable:

   sudo chmod +x /etc/acpi/reboot.sh
   

Now the systemctl reboot command will be performed when you press the button three times, within 30 secconds.

Create custom shortcut and bind a script to it

1. Crate a script /usr/local/bin/my_rbt (it could be named and located whenever you want) and make it executable. Here is a single command line that does that:

   $ echo -e '#!/bin/sh\nsudo systemctl reboot' | sudo tee /usr/local/bin/my_rbt && sudo chmod +x /usr/local/bin/my_rbt
   #!/bin/sh
   systemctl reboot
   

2. The problem is (within this approach) we must use sudo to execute the script and should allow the users to do that without password - here are provided more details about this step: How do I run specific sudo commands without a password? So we must crate a file located in /etc/sudoers.d/, called for example my_rbt. For this purposes we should use the command visudo -f:

   sudo visudo -f /etc/sudoers.d/my_rbt
   

   The content of the file should be:

   ALL ALL=NOPASSWD: /usr/local/bin/my_rbt
   

3. Go to System Settings → Keyboard → Shortcuts (tab) → Custom Shortcuts (section) → Add new +.

   

   • In the Custom shortcut window type:

   • Name: reboot

   • Command: sudo /usr/local/bin/my_rbt
   • Click on Apply

4. Click on Disabled in the right column and press the discussed button.

   

That's it.

It appears that for Lenovo laptops (at least my G575) the OneKey Recovery key is another key.

Using the xev command, you can find out the scancode. xev will open a window with a black square, move your mouse inside it and then press the OKR key.

KeyPress event, serial 51, synthetic NO, window 0x1600001,
    root 0x497, subw 0x1600002, time 1092364, (50,41), root:(52,479),
    state 0x0, keycode 156 (keysym 0x1008ff41, XF86Launch1), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 51, synthetic NO, window 0x1600001,
    root 0x497, subw 0x1600002, time 1092364, (50,41), root:(52,479),
    state 0x0, keycode 156 (keysym 0x1008ff41, XF86Launch1), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

You can see the keycode as keycode 156.

After finding the keycode, all you need to look up is how to map a keycode to a specific action. Here's some helpful questions:

• How do I make the Caps Lock key a third Shift key?
• https://unix.stackexchange.com/questions/188164/override-a-few-keycodes-with-xkb