[PATCH] installer: suppress kernel info/debug messages

[Badrikesh Prusty]

Lower the kernel log level to 4 to suppress notice, info, and debug
messages on the console.
This prevents audit and driver messages from cluttering the screen
while keeping critical errors and systemd service status output
visible, resulting in a cleaner installer UI.

Signed-off-by: Badrikesh Prusty <badrikes...@siemens.com>
---
meta-isar/recipes-core/images/isar-image-installer.bb | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/meta-isar/recipes-core/images/isar-image-installer.bb b/meta-isar/recipes-core/images/isar-image-installer.bb
index 3511f3f6..a58f8849 100644
--- a/meta-isar/recipes-core/images/isar-image-installer.bb
+++ b/meta-isar/recipes-core/images/isar-image-installer.bb
@@ -11,7 +11,8 @@ DESCRIPTION = "Example of a ISAR based Installer Image"
INSTALLER_WKS_FILE ??= "installer-efi.wks.in"
WKS_FILE = "${INSTALLER_WKS_FILE}"

-ADDITIONAL_KERNEL_CMDLINE ??= ""
+# Hide kernel warning/info/debug messages
+ADDITIONAL_KERNEL_CMDLINE ??= "loglevel=4"

OVERRIDES .= "${@':unattended-installer' if bb.utils.to_boolean(d.getVar('INSTALLER_UNATTENDED')) else ''}"
ADDITIONAL_KERNEL_CMDLINE:append:unattended-installer = " \
--
2.47.3

[Anton Mikanovich]

Applied to next, thanks.

[Florian Bezdeka]

On Mon, 2026-01-05 at 11:24 +0200, Anton Mikanovich wrote:
> Applied to next, thanks.

Why? There was a v2 on the list already. Hiding warnings is not a good
idea.

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[Badrikesh Prusty]

Hi Florian,

As per your previous suggestion, the warning messages are no longer hidden.

This has already been addressed by changing the log level from loglevel=3 to

loglevel=4 in v2 of the patch. With loglevel=4, warning messages are displayed,

and only info and debug messages are skipped.

Thanks,

Badrikesh

[Anton Mikanovich]

Hello Florian,

You are commenting it in v2 thread already.
Correct version was merged.
Badrikesh didn't add new version tag, so it creates some confusion.

[Florian Bezdeka]

On Mon, 2026-01-05 at 16:16 +0100, 'Florian Bezdeka' via isar-users
wrote:

> On Mon, 2026-01-05 at 11:24 +0200, Anton Mikanovich wrote:
> > Applied to next, thanks.
>
> Why? There was a v2 on the list already. Hiding warnings is not a good
> idea.

Ignore that. v2 was merged but was never tagged as v2. This is where the
confusion starts.

> To view this discussion visit https://groups.google.com/d/msgid/isar-users/6229e195c881f23c581aa5dba4664d52daf410c8.camel%40siemens.com.

[Heinisch, Alexander]

On Mon, 2026-01-05 at 11:24 +0200, Anton Mikanovich wrote:
> Applied to next, thanks.

Sry for the late reply - holiday season :-)

>
> 23/12/2025 04:15, 'Badrikesh Prusty' via isar-users wrote:
> > Lower the kernel log level to 4 to suppress notice, info, and debug
> > messages on the console.
> > This prevents audit and driver messages from cluttering the screen
> > while keeping critical errors and systemd service status output
> > visible, resulting in a cleaner installer UI.
> >
> > Signed-off-by: Badrikesh Prusty <badrikes...@siemens.com>
> > ---
> >   meta-isar/recipes-core/images/isar-image-installer.bb | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/meta-isar/recipes-core/images/isar-image-installer.bb
> > b/meta-isar/recipes-core/images/isar-image-installer.bb
> > index 3511f3f6..a58f8849 100644
> > --- a/meta-isar/recipes-core/images/isar-image-installer.bb
> > +++ b/meta-isar/recipes-core/images/isar-image-installer.bb
> > @@ -11,7 +11,8 @@ DESCRIPTION = "Example of a ISAR based Installer
> > Image"
> >   INSTALLER_WKS_FILE ??= "installer-efi.wks.in"
> >   WKS_FILE = "${INSTALLER_WKS_FILE}"
> >  
> > -ADDITIONAL_KERNEL_CMDLINE ??= ""
> > +# Hide kernel warning/info/debug messages
> > +ADDITIONAL_KERNEL_CMDLINE ??= "loglevel=4"
> >

I guess the reason for that is to have readable output while running
the target bootstrapper?
As for the installer image this service is run pretty late, maybe you
could reduce kernel logs when starting that service? (e.g.
PreStart=...)

> >  
> >   OVERRIDES .= "${@':unattended-installer' if
> > bb.utils.to_boolean(d.getVar('INSTALLER_UNATTENDED')) else ''}"
> >   ADDITIONAL_KERNEL_CMDLINE:append:unattended-installer = " \

--
Alexander Heinisch
Siemens AG
www.siemens.com

[Florian Bezdeka]

On Fri, 2026-01-09 at 10:54 +0000, Heinisch, Alexander (FT RPD CED SES-

Which service? We're talking about kernel cmdline arguments here. Those
have impact on system startup/boot already. PreStart= seems to point
into the direction of systemd, which is involved way later in the boot
process.

[Heinisch, Alexander]

Prusty mentioned "... resulting in a cleaner installer UI.", so I was
assuming he is concerned about the installer / target-bootstrapper
output.

If so reducing/limiting kernel logs from the execution of the target-
bootstrapper service (and yes that's a systemd service) onwards should
be sufficient for the specific case, while preserving default logs
during boot.

Else, if not, and the kernel log itself is for some reason too
cluttered for audit aso., then why should it only be appled to the
installer image and not in general?

>
> >
> > > >  
> > > >   OVERRIDES .= "${@':unattended-installer' if
> > > > bb.utils.to_boolean(d.getVar('INSTALLER_UNATTENDED')) else ''}"
> > > >   ADDITIONAL_KERNEL_CMDLINE:append:unattended-installer = " \
> >
> >