Re: Caching kernel messages at boot w/PATCH

From: Jan Engelhardt
Date: Fri Jun 09 2006 - 16:05:13 EST


>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
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