@c4pp4 x1000 thanks!!!

@Flohack thanks for all your responses! much appreciated!!!

Sure, I agree let's not use google's adb, one thing less from google the better!

What I am asking, is if there is any chance except from debug messages to get an actual shell via that serial cable of pinephone?

What are the chance I can get it working by just editing the inittab like with the previous classic example?

Has anybody tried it already?

I never had to use SSH on the UBports; adb shell was adequate. Of course I can try SSH, but is it possible to get more than debug (to get bash shell actually) from the serial cable?

Like the classic following example from a line at /etc/inittab ?

T0:123:respawn:/sbin/getty -L ttyS0 115200 vt100

Source::
https://help.ubuntu.com/community/SerialConsoleHowto

Can I get a serial console (like ttyS0) on the Pinephone using the "PINEBOOK SERIAL CONSOLE" cable with the CH340 chipset?

Specifically, I would like to have access to the bash shell, like when using adb shell with a Nexus 5 running UBports.