As we know, when we startup the system (after grub) and when we shutdown the system, many logs will be printed on screen.
I know that the kernel would write some logs of the kernel. But how about the others? Who writes them?
As I know, Ubuntu uses
systemd and there are some logs from
systemd. I want to know if it is possible that I could create a service of
systemd, which can write some logs on screen while starting up and shutting down?