Jetson TX2 SoC Watchdog - how does it work

I would like to know how does the SoC WD works.
I’m using TX2i, with the provided cboot and 2020.07 (using Yocto meta-tegra).
I can see that the cboot initializes the WD periphery.
What is the flow from there?

  • The Uboot kicks the WD from there on (later the Kernel/some user-space daemon)?
  • The system relies on the boot flow to finish before 120 seconds (I believe this is the default time) and then the Kernel kicks it?
  • The periphery is only initialized in the cboot but if a user-space process is not enabling the WD it must not be kicked?
  • Something else?

Something a bit different, I think I saw that the SoC WD can be replaced with the PMIC WD. Is it true? what is the difference?

I think below link should have much information about it.