[gentoo-user] Re: Serial console stops working as soon as openrc starts

[Grant Edwards <grant.b.edwards@gmail.com>]

On 2023-09-09, Grant Edwards <grant.b.edwards@gmail.com> wrote:
> I've set up a serial console by adding the following to my kernel
> command line:
>
>     console=ttyS0,115200 console=tty1
>
> It works fine for the first few seconds as the kernel starts up. All
> of the expected messages are sent out ttyS0.
>
> But, soon after init starts, the serial console stops working.

That's because one of the first things openrc runs in
/etc/init.d/dmesg, and it changes the kernel logging level to the
value defined in /etc/conf.d/dmesg (which defaults to 1).

Changing the level in /etc/conf.d/dmesg from 1 to 8 allowed the serial
console to continue working as I wanted it to.

[I spent an entire day trying to get serial logging to work on Ubuntu
with systemd, and got exactly nowhere. After replacing Ubuntu/systemd
with Gentoo/openrc it didn't take long to track down the answer in the
openrc docs.]