Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753102AbbDGKYw (ORCPT ); Tue, 7 Apr 2015 06:24:52 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:38315 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752570AbbDGKYu (ORCPT ); Tue, 7 Apr 2015 06:24:50 -0400 Date: Tue, 7 Apr 2015 12:24:45 +0200 From: Ingo Molnar To: Alexander Kuleshov Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Greg Kroah-Hartman , LKML Subject: Re: [PATCH] x86/earlyprintk: setup earlyprintk as early as possible Message-ID: <20150407102445.GA13658@gmail.com> References: <1428326234-10067-1-git-send-email-kuleshovmail@gmail.com> <20150407095228.GA13093@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1564 Lines: 38 * Alexander Kuleshov wrote: > 2015-04-07 15:52 GMT+06:00 Ingo Molnar : > > > > It would be nice to test it via a well placed printk() and check that > > before the patch the message doesn't go to the serial console and > > after the patch the message indeed arrives on the early serial console > > - or something like that. > > I have tested this patch when i wrote it and early_printk does not print > anything before the parse_early_param. But i don't know how to show this > in code in a correct way. [...] Just add a debug printk() for your own testing, right after the param initialization call, to be confident that the early console indeed works. > which i removed in the previous patch > (https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=91d8f0416f3989e248d3a3d3efb821eda10a85d2)? > > Any one another question about this. I submited patch only for > head64.c and it does not affect kernel for i386, because i'm not > sure where is the best place to setup earlyprintk in the head32.c. I > thought to put it in the start of i386_start_kernel(void) (from > head32.c) but not sure about it. I'd use i386_start_kernel() on 32-bit and x86_64_start_kernel() on 64-bit - but I haven't tested whether it actually works. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/