linux-kernel - Re: Early printk behaviour

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Date:	Mon, 20 Aug 2007 10:01:12 +0200
From:	Gerd Hoffmann <kraxel@...hat.com>
To:	Robin Getz <rgetz@...ckfin.uclinux.org>
CC:	Mike Frysinger <vapier.adi@...il.com>, linux-kernel@...r.kernel.org
Subject: Re: Early printk behaviour

Robin Getz wrote:

>> Hmm, yes, should be doable in generic code.  Check whenever the current
>> console has CON_BOOT set and if so unregister it.
> 
> Something like:
> 
> +++ kernel/printk.c     (working copy)
> +int __init disable_boot_consoles(void)
> +{
> +       struct console *con;
> +
> +       for (con = console_drivers; con; con = con->next) {
> +               if (con->flags & CON_BOOT) {
> +                       printk(KERN_INFO "Unregister BootConsole %s%d\n",
> +                               con->name, con->index);
> +                       unregister_console(con);
> +               }
> +       }
> +       return 0;
> +}
> +late_initcall(disable_boot_consoles);

Yep, that should work.  You can drop the loop though.  You can't
register a boot console if another console exists, and the first
non-boot console replaces the boot console, thus you never ever have
more than one console in case the boot console is still active.

The printk should be all lowercase like the other printk's in the file.

Other than that it loosk fine.

cheers,
  Gerd

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