By passing the kernel panic parameter, the system automatically resets after 3 seconds when kernel panic happen
example:
bootargs 'board=xxxxx console=ttyS0,115200 ubi.mtd=overlay rootfs=/dev/mtdblock:rootfs rootfstype=squashfs noinitrd init=/sbin/init panic=3'
[ 4.850000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 4.850000] Rebooting in 3 seconds..