Hi,
I have already post a similar issue in the previous post.
I'm using initramfs shell using initramfs-framework in Yocto environment.
I found that watchdog reboots after some time (the default is 32 seconds) if the initramfs doesn't fully boot the system by entering systemd.
The weird thing is though, this happens even WATCHDOG_HANDLE_BOOT_ENABLED is set correctly.
According to the source code of watchdog_dev.c in Linux Kernel if WATCHDOG_HANDLE_BOOT_ENABLED=y is set the kernel watchdog thread should handle watchdog correctly until a userspace program (systemd?) takes over /dev/watchdog. However, watchdog still reboots the board.
https://elixir.bootlin.com/linux/v4.14/source/drivers/watchdog/watchdog_dev.c#L1124
I set similar yocto environments (with WATCHDOG_HANDLE_BOOT_ENABLED=y) in Raspberry Pi 3 and Beaglebone Black, and their kernel seems to handle watchdog correctly as they don't reboot in initramfs environment for a long time. Only STM32MP1 seems to have problems with watchdog.
