Hi,
On (12/07/17 14:48), Petr Mladek wrote:
[..]
> > This patch introduces a `console_msg_format=' command line option,
> > to switch between different message formatting on serial consoles.
> > For the time being we have just one option - syslog. This option
> > makes serial console messages to appear in syslog format, matching
> > the `dmesg --raw' and `cat /proc/kmsg' output formats:
>
> I have realized that 'cat /proc/kmsg' did not work. It can be done using:
hm, it does work on my system. what do you mean by 'did not work'?
> Also the format is more comlicated here, see printk.c:
>
> * /dev/kmsg exports the structured data in the following line format:
> * "<level>,<sequnum>,<timestamp>,<contflag>[,additional_values, ...
> ];<message text>\n"
that's /dev/kmsg. /dev/kmsg != /proc/kmsg. I never mentioned /dev/kmsg
in my commit. /dev/kmsg prints the extended stuff, /proc/kmsg does not.
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt
> > b/Documentation/admin-guide/kernel-parameters.txt
> > index 28467638488d..2dd91c5073f9 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -643,6 +643,16 @@
> > console=brl,ttyS0
> > For now, only VisioBraille is supported.
> >
> > + console_msg_format=
> > + [KNL] Control message format
> > + By default we print messages in "[time stamp] text\n"
> > + format (time stamp may not be printed, depending on
> > + CONFIG_PRINTK_TIME or `printk_time' param).
> > + syslog
> > + Switch to syslog format (similar to "dmesg --raw" or
> > + reading from /proc/kmsg): "<%u>[time stamp] text\n"
>
> To be precise, it exactly the same as "dmesg -S --raw". Also it is the
> format used by SYSLOG_ACTION_READ* actions of the syslog syscall.
hmm... `dmesg -S --raw' doesn't show anything on my system. `dmesg --raw'
matches the console_msg_format=syslog.
> > +static int __init console_msg_format_setup(char *str)
> > +{
> > + if (!strncmp(str, "syslog", 6))
> > + console_msg_format = MSG_FORMAT_SYSLOG;
>
> It might make sense to accept also the "default" format.
>
> > + return 1;
> > +}
> > +__setup("console_msg_format=", console_msg_format_setup);
>
> I would use early_param() so that it takes effect as soon as possible.
ok. can take a look.
-ss
