Issue for serial0 port on Stretch.

[fromJPN]

Hello.
please tell me.

my environment:
2017-07-05-raspbian-jessie-lite.img
or
2018-03-13-raspbian-stretch-lite.img
on
raspberry pi 3 model B

I conected a serial cable bitwin a terminal and GPIO physical pins 15,16(serial0 port).
I modified "console=tty1" to "console=ttyAMA0" in "/boot/cmdline.txt" file.
I had append next two line to "/boot/config.txt" file bottom.
dtoverlay=pi3-disable-bt
enable_uart=1

When Jessie, there was no problem at all.

But, for Stretch, it has following problem.
When you turn on the power, the login prompt is displayed.
If I do not enter anything here, the cursor should stay in there on forever.

But, Stretch, after 15 seconds, the cursor will move to the left end in automaticay.
If I finish log in within 15 seconds, the same thing happens on the command line.
After all, the cursor jumps over the command prompt and moves to the left end.

I have use the same terminal, same cable and same hardware as Jessie's time.
why?

[Ernst]

It is a bug. I did find some information sometime ago but I forgot where as it has been noticed and does not really hurt.
Maybe it will be fixed sometime in the future.

viewtopic.php?t=192960

[fromJPN]

Thank you very much for your quick reply.

[DougieLawson]

I conected a serial cable bitwin a terminal and GPIO physical pins 15,16(serial0 port).
I modified "console=tty1" to "console=ttyAMA0" in "/boot/cmdline.txt" file.
I had append next two line to "/boot/config.txt" file bottom.
dtoverlay=pi3-disable-bt
enable_uart=1

You need

Code: Select all

 console=serial0,115200 

in cmdline.txt

The UART is pin#8 GPIO14 TX and pin#10 GPIO15 RX
https://pinout.xyz/pinout/uart

That config stuff is all done for you with sudo raspi-config

[fromJPN]

To Dougie Lawson

Thank you very much for your reply.

What you wrote is correct.
I have been setting from the beginning as you are writing.
But when I write here I made a mistake.
I think that this problem is a bug as Ernst stated.