Caching kernel messages at boot

Caching kernel messages at boot

[s.a.]

Hi,
Is there a way to hide the kernel messages from the screen at boot ?
Best Regards
Steph

Re: Caching kernel messages at boot

[Paolo Ornati]

On Fri, 09 Jun 2006 15:20:45 +0000
"s.a." <sancelot@free.fr> wrote:

> Hi,
> Is there a way to hide the kernel messages from the screen at boot ?

from: Documentation/kernel-parameters.txt

"quiet" boot option

-- 
	Paolo Ornati
	Linux 2.6.17-rc6-mm1-lockdep on x86_64

Re: Caching kernel messages at boot

[Richard Mittendorfer]

Also sprach "s.a." <sancelot@free.fr> (Fri, 09 Jun 2006 15:20:45 +0000):
> Hi,
> Is there a way to hide the kernel messages from the screen at boot ?

Use the bootparameter "quiet" e.g. <vmlinuz-image> root=/dev/sda3 quiet
or one of those framebuffer splash screens.

> Best Regards
> Steph

sl ritch

Re: Caching kernel messages at boot

[linux-os (Dick Johnson)]

On Fri, 9 Jun 2006, s.a. wrote:

> Hi,
> Is there a way to hide the kernel messages from the screen at boot ?
> Best Regards
> Steph

Sure, but it depends upon your boot loader. If you are using grub,
you put 'quiet' on the command-line in /boot/grub/grub.conf. If using
LILO, you can use append="console=null" in lilo.conf. The latter
causes a bit of a problem later on because no kernel messages will
ever be sent to the console. This could be fixed by making your own
'init' which opens /dev/console for the three standard file numbers,
then execs the real /sbin/init. You can put the temporary init
program name on the command-line as well as init=/sbin/my.init.


Cheers,
Dick Johnson
Penguin : Linux version 2.6.16.4 on an i686 machine (5592.88 BogoMips).
New book: http://www.AbominableFirebug.com/
_
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Re: Caching kernel messages at boot w/PATCH

[Jan Engelhardt]

>Hi,
>Is there a way to hide the kernel messages from the screen at boot ?
>Best Regards
>Steph
>
Except for the sole "quiet" flag, I have this in my kernel tree:

AS_13-conlevel.diff
diff --fast -Ndpru linux-2.6.17-rc6~/kernel/printk.c linux-2.6.17-rc6+/kernel/printk.c
--- linux-2.6.17-rc6~/kernel/printk.c	2006-06-06 02:57:02.000000000 +0200
+++ linux-2.6.17-rc6+/kernel/printk.c	2006-06-08 22:24:16.847058000 +0200
@@ -697,6 +697,14 @@ int __init add_preferred_console(char *n
 	return 0;
 }
 
+static __init int set_conlevel(char *str) {
+    if(*str >= '0' && *str <= '9')
+        *console_printk = *str - '0';
+    return 1;
+}
+
+__setup("conlevel=", set_conlevel);
+
 /**
  * acquire_console_sem - lock the console system for exclusive use.
  *
#<<eof>>

It allows one to finely specify how much noise or silence the user wants.
conlevel=4 makes it quite silent (still shows some minor erros [1]), and 
decreasing that of course will make it even more silent.

[1]
sda: asking for cache data failed
sda: assuming drive cache: write through
piix4_smbus 0000:00:07.3: Host SMBus controller not enabled!

These three are then gone for me with conlevel=3. dmesg still 
records all messages (a good thing(tm)).


Jan Engelhardt
--