Re: [OE-core] [PATCH RFC walnascar 2/3] systemd: always depend on the explicit serial console units

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Hi,

On Wed, Apr 23, 2025 at 02:18:42PM +0300, Mikko Rapeli via lists.openembedded.org wrote:
> On Tue, Apr 22, 2025 at 08:00:52PM +0100, Ross Burton wrote:
> > The systemd-serialgetty recipe generates explicit units for consoles
> > that are defined in SERIAL_CONSOLES, and if that variable is not defined
> > then just produces an empty package.
> > 
> > Even when systemd has been configured to use the getty generator, if
> > there are explicit consoles defined then we should respect them.  Don't
> > conditionalise the dependency on systemd-serialgetty so that we always
> > pull in the explicit consoles.
> 
> So all boots of genericarm64 on all HW now wait for the configured
> SERIAL_CONSOLES timeouts.
> 
> How should that be fixed? Unsetting SERIAL_CONSOLES in genericarm64 machine config?
> So systemd-serialgetty is allowed to be machine specific but not systemd itself?

To fix the "poky-altcfg" distro or "poky" with systemd boot slowdown on genericarm64,
systemd-serialgetty should either be removed or see an empty SERIAL_CONSOLES set currently
in the machine config.

A genericarm64 machine specific bbappend could do this, or in genericarm64
machine config could have:

SERIAL_CONSOLES:poky-altcfg ?= ""

This sets for all which may break some other things so maybe it's better to do this only for 
systemd-serialgetty in machine config with:

SERIAL_CONSOLES:poky-altcfg:pn-systemd-serialgetty ?= ""

This would not work for plain "poky" distro if someone enabled systemd as init.
For that, something like:

SERIAL_CONSOLES:pn-systemd-serialgetty ?= "
    ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', \
    '', '115200;ttyAMA0 115200;hvc0 115200;ttyS0 115200;ttyS1 115200;ttyS2', d)} \
"

These either make SERIAL_CONSOLES depend on "systemd" in DISTRO_FEATURES inside
machine config, so I'm not sure if this is allowed or not.

A genericarm64 machine specific bbappend to systemd-serialgetty to disable the
package or clear out SERIAL_CONSOLES is "systemd" in DISTRO_FEATURES would be
better then?

systemd would remain machine agnostic but systemd-serialgetty would be machine specific
since it takes SERIAL_CONSOLES as input anyway.

I can't decide between these. :/

Cheers,

-Mikko