The following table indicates which actions take place depending on power supplies and working modes:

Main power Battery backup Working mode After a tamper event…​

dwg x mark

dwg x mark

-

-

dwg x mark

✔

power off

  • Register the event in NVRAM

  • Activate the output

✔

indifferent

power off

  • Register the event

  • Activate the output

  • Power on the system and U-Boot catches the tamper event

✔

indifferent

suspend

  • Register the event

  • Activate the output

  • Wake up the system with an IRQ that can be processed by user space

✔

indifferent

running

  • Register the event

  • Activate the output

  • Trigger the tamper IRQ that can be processed by user space