Control WDT directly

I need that WDT start at the boot of the SOM, and that my application controls it. I read WDT is controlled from systemd, is it possible disable this feature and control it directly from the container by my application with /dev/watchdog.
I tried to set in /etc/systemd/system.conf

RuntimeWatchdogSec=off

but

sudo journalctl |grep -i ‘hardware watchdog’ says that wdt is controlled by systemd

Apr 28 17:42:26 colibri-imx8x-06846833 systemd[1]: Using hardware watchdog ‘i.MX SC watchdog timer’, version 0, device /dev/watchdog0

and I cannot open with
api_watchdog_fd = open(“/dev/watchdog”, O_RDWR);
inside the container (I have “/dev/watchdog:/dev/watchdog” in the yaml file)

and what about Uboot it activates wdt, I would like to be sure if something goes wrong also with linux boot.

Greetings @fabrizio.camagna,

With regards to using the watchdog yourself could you see the other thread here: Watchdog device always busy

Does this solve your issue?

Best Regards,
Jeremias