Always root autologin for prebuilt debian image?

Hi,

I tried the prebuilt debian image, but I install the rootfs into a LV upon the NVME, using a new ESP partition on the NVME. With everything (kernel cmdline options for root, rebuilt the initramfs to include LVM2 hooks, change fstab, using uboot in SPI flash etc) modified to handle the LVM2, the system boots fine.

The only distro related problem is, I always find the tty will auto login with root.

I guess there is some first-time boot config? And how to disable the first-time special configs?

Thanks.