I was looking into the use of the watchdog device today on the Raspberrry Pi version. What I found is that the kernel module does appear to be loaded:
$ lsmod | grep wdt
bcm2835_wdt 16384 0
While I couldn’t find a daemon or configuration in systemd, I was able to get this
$ sudo wdctl
wdctl: write failed: Invalid argument
Device: /dev/watchdog
Identity: Broadcom BCM2835 Watchdog timer [version 0]
Timeout: 15 seconds
Timeleft: 14 seconds
FLAG DESCRIPTION STATUS BOOT-STATUS
KEEPALIVEPING Keep alive ping reply 0 0
MAGICCLOSE Supports magic close char 0 0
SETTIMEOUT Set timeout (in seconds) 0 0
I’m not sure how this is configured, and I’d like to make sure that it is properly configured such that if the system freezes, it will get rebooted properly.