From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760563AbYFLXBQ (ORCPT ); Thu, 12 Jun 2008 19:01:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755675AbYFLXBD (ORCPT ); Thu, 12 Jun 2008 19:01:03 -0400 Received: from relay2.sgi.com ([192.48.171.30]:44355 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753727AbYFLXBC (ORCPT ); Thu, 12 Jun 2008 19:01:02 -0400 Message-ID: <4851AAAD.8050105@sgi.com> Date: Thu, 12 Jun 2008 16:01:01 -0700 From: Mike Travis User-Agent: Thunderbird 2.0.0.6 (X11/20070801) MIME-Version: 1.0 To: Yinghai Lu CC: Ingo Molnar , Andrew Morton , Thomas Gleixner , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] x86: Add config option to setup early serial console References: <20080612224247.486614000@polaris-admin.engr.sgi.com> <20080612224247.623141000@polaris-admin.engr.sgi.com> <86802c440806121548s71ff31eapc5f389cfa94ea237@mail.gmail.com> In-Reply-To: <86802c440806121548s71ff31eapc5f389cfa94ea237@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yinghai Lu wrote: > On Thu, Jun 12, 2008 at 3:42 PM, Mike Travis wrote: >> * Add config option EARLY_SERIAL_CONSOLE to enable early >> printk's to be directed to the serial console. >> >> Based on linux-next >> >> Signed-off-by: Mike Travis >> --- >> >> --- >> arch/x86/Kconfig.debug | 9 +++++++++ >> arch/x86/kernel/early_printk.c | 4 ++++ >> 2 files changed, 13 insertions(+) >> >> --- linux-2.6-next.orig/arch/x86/Kconfig.debug >> +++ linux-2.6-next/arch/x86/Kconfig.debug >> @@ -29,6 +29,15 @@ config EARLY_PRINTK >> with klogd/syslogd or the X server. You should normally N here, >> unless you want to debug such a crash. >> >> +config EARLY_SERIAL_CONSOLE >> + bool "Early Serial Console" >> + default n >> + help >> + Initializes the early console to be the serial port. The default >> + is to use the VGA console. >> + >> + This is useful for server systems that do not have a VGA console. >> + >> config DEBUG_STACKOVERFLOW >> bool "Check for stack overflows" >> depends on DEBUG_KERNEL >> --- linux-2.6-next.orig/arch/x86/kernel/early_printk.c >> +++ linux-2.6-next/arch/x86/kernel/early_printk.c >> @@ -193,7 +193,11 @@ static struct console simnow_console = { >> }; >> >> /* Direct interface for emergencies */ >> +#ifdef CONFIG_EARLY_SERIAL_CONSOLE >> +static struct console *early_console = &early_serial_console; >> +#else >> static struct console *early_console = &early_vga_console; >> +#endif >> static int early_console_initialized; >> >> void early_printk(const char *fmt, ...) >> > > can you check if it can work with > console=uart8250,io,0x3f8,115200 > > that is early console, and will switch to normal console automatically > > YH I'll rework the patch to enable the serial console as early as possible. Currently, it's done quite a ways down in start_kernel(). Thanks, Mike