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From: devzero@web.de
To: Miquel van Smoorenburg <miquels@cistron.nl>
Cc: linux-kernel@vger.kernel.org
Subject: Re: serial console _after_ boot ? - was: Redirect kernel console
Date: Thu, 03 Jan 2008 21:29:30 +0100	[thread overview]
Message-ID: <84315412@web.de> (raw)

>>>i was wondering how to make kernel messages appear on /dev/ttyS0
>>without a reboot, i.e. kernelparam "console=ttyS0"
>>
>>The solution is simple... the following piece of code is inside
>>opensuse-10.3/src/sysvinit-2.86-115.src.rpm#showconsole-1.08.tar.bz2#showconsole-1.08/blogd.c
>>
>>    (void)ioctl(0, TIOCCONS, NULL);  /* Undo any current map if any */
>>    if (ioctl(pts, TIOCCONS, NULL) < 0)
>>        error("can not set console device to %s: %s\n", ptsname,
>>strerror(errno));
>>
>>so I suppose that's it. Write up a new program that calls the ioctl
>>on a tty, and you should be done. IOW:
>
>TIOCCONS only works for pseudo terminals.
>
>Besides, it only redirects stuff you send to /dev/console. It
>doesn't change what devices printk() prints to. Currently there
>is no way to change that on a running kernel.
>
>Mike.

too bad, but thanks for the info.
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             reply	other threads:[~2008-01-03 20:29 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-03 20:29 devzero [this message]
  -- strict thread matches above, loose matches on Subject: below --
2008-01-03 16:02 serial console _after_ boot ? - was: Redirect kernel console devzero
2008-01-03 14:39 devzero
2008-01-03 15:04 ` Jan Engelhardt
2008-01-03 12:43 devzero
2008-01-03 13:27 ` Jan Engelhardt
2008-01-03 17:55   ` Miquel van Smoorenburg

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