Tiny Power Button Signal


Linux Kernel Configuration
└─>Power management and ACPI options
└─>ACPI (Advanced Configuration and Power Interface) Support
└─>Tiny Power Button Signal
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Default signal to send to init in response to the power button.

Likely values here include 38 (SIGRTMIN+4) to power off, or 2
(SIGINT) to simulate Ctrl+Alt+Del.