Watchdog bites when rainier is at runtime

[shenki]

When booting the rainier image in qemu, watchdog 0 will bite some time into the boot, once userspace is up. We can confirm it's watchdog0 by running with -d cpu_reset:

Watchdog timer 0 expired.

Userspace seems to arm watchdog1:

[   45.911714] systemd[1]: Using hardware watchdog 'aspeed_wdt', version 0, device /dev/watchdog1
[   45.916587] systemd[1]: Set hardware watchdog to 2min.

[shenki]

On a faster host this doesn't always occur. On a slower machine it occurs often, after about 10 minutes.