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Re: Fixing the missing serial console after installation issue

On 09/30/2017 08:17 PM, John Paul Adrian Glaubitz wrote:
On 09/30/2017 07:19 PM, Frank Scheiner wrote:
Not sure, but [1] says that it should be sufficient to add all console devices
to the kernel command line for systemd to detect and activate them, e.g.
`console=ttyS0,9600n8` - which includes port and configuration.

Yes, I'm aware of that and that's what people usually use to enable the serial
console post installation. However, it's most likely not what we would want to
use as adding it to the kernel command line assumes that you know what type
of bootloader is being used and you would have to add case-matching for the
various bootloader types.

But how does the kernel then know which serial device to use as console if it's not selected via the kernel's command line?

As alternative, [1] also explains how to configure systemd directly via a systemd unit further below (in "Serial Terminals").

Yes, that's basically what I already mentioned in my original mail. But, as I said
before, I'm not sure how to pass any serial configuration parameters using this
method. OTOH, I'm also not sure whether setting the parameters is actually

[1] mentions that the parameters (baud rate, etc.) for the getty tool - agetty in this case - can be modified in the system unit:

# cp /usr/lib/systemd/system/serial-getty@.service /etc/systemd/system/serial-getty@ttyS2.service
# vi /etc/systemd/system/serial-getty@ttyS2.service
 .... now make your changes to the agetty command line ...
# ln -s /etc/systemd/system/serial-getty@ttyS2.service /etc/systemd/system/getty.target.wants/
# systemctl daemon-reload
# systemctl start serial-getty@ttyS2.service

Isn't that what you're looking for?

UPDATE: Just saw that you solved it, but the info above might be still useful.

[1]: http://0pointer.de/blog/projects/serial-console.html

Or does systemd not enable a serial console for the mentioned users despite
using a serial console configuration in the kernel command line?

What users? As you have explained yourself, systemd recognizes the console=$dev
setting from the kernel command line and uses that to spawn a getty on this
particular console.

Yes, sure, but I didn't know if what I proposed and what worked in the past also worked for the mentioned users, i.e. these users:

On 09/30/2017 10:54 AM, John Paul Adrian Glaubitz wrote:
Some users of Linux on sparc64 have noticed that the serial console is not working
directly after installation.


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