Many thanks,
you’ve explained very well.
What I have known this days.
Really, service console-getty.service should be disabled.
Service serial-getty@ttyGS0.service should be active (and according symbolic link should be created).
ps auxww | grep agetty should show ttyGS0 device and, if no, check status of your serial-getty instances.
$ systemctl show serial-getty@ttyGS0.service
Sadly, the mine serial service is not starting. I’d checked journalctl | grep serial-getty and saw dependency and timeout error.
systemctl start serial-getty@ttyGS0.service
It starts without problems and I see my serial console working as it was a few months ago. The login prompt was sent to my PC’s picocom!
Now I should repair my OS startup sequence.
One month ago I’d fully converted my SD card partition to LUKS-crypted F2FS. Now my smartphone starts long. (A 10 minutes; the decrypting of 512 Gb partition costs much.) As I see, this delay breaks systemd timeouts. I tried to fix this setting but had no luck. (Maybe you have advice?)
Then I just fixed my /etc/rc.local file adding systemctl start serial-getty@ttyGS0.service. And it bricked my phone. I think the problem is systemd fails recursevely falling in starting its services. How could I unbrick it now? Everything I need is just fix my /etc/rc.local back.