Messages in this thread | | | From | "Miquel van Smoorenburg" <> | Subject | Re: serial console _after_ boot ? - was: Redirect kernel console | Date | 03 Jan 2008 17:55:02 GMT |
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In article <Pine.LNX.4.64.0801031423070.26693@fbirervta.pbzchgretzou.qr>, Jan Engelhardt <jengelh@computergmbh.de> wrote: > >On Jan 3 2008 13:43, devzero@web.de wrote: >> >>hi ! >> >>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.
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