Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750890AbWIDIcP (ORCPT ); Mon, 4 Sep 2006 04:32:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751097AbWIDIcP (ORCPT ); Mon, 4 Sep 2006 04:32:15 -0400 Received: from mtagate5.de.ibm.com ([195.212.29.154]:59116 "EHLO mtagate5.de.ibm.com") by vger.kernel.org with ESMTP id S1750890AbWIDIcN (ORCPT ); Mon, 4 Sep 2006 04:32:13 -0400 Subject: Re: [PATCH 00/26] Dynamic kernel command-line From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Nigel Cunningham Cc: Paul Mackerras , Alon Bar-Lev , Andi Kleen , Matt Domsch , Andrew Morton , linux-kernel@vger.kernel.org, johninsd@san.rr.com, davej@codemonkey.org.uk, Riley@williams.name, trini@kernel.crashing.org, davem@davemloft.net, ecd@brainaid.de, jj@sunsite.ms.mff.cuni.cz, anton@samba.org, wli@holomorphy.com, lethal@linux-sh.org, rc@rc0.org.uk, spyro@f2s.com, rth@twiddle.net, avr32@atmel.com, hskinnemoen@atmel.com, starvik@axis.com, ralf@linux-mips.org, matthew@wil.cx, grundler@parisc-linux.org, geert@linux-m68k.org, zippel@linux-m68k.org, heiko.carstens@de.ibm.com, uclinux-v850@lsi.nec.co.jp, chris@zankel.net In-Reply-To: <1157338220.10336.147.camel@nigel.suspend2.net> References: <200609040050.13410.alon.barlev@gmail.com> <17659.26177.846522.226410@cargo.ozlabs.ibm.com> <1157338220.10336.147.camel@nigel.suspend2.net> Content-Type: text/plain Organization: IBM Corporation Date: Mon, 04 Sep 2006 10:32:07 +0200 Message-Id: <1157358727.5078.11.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1179 Lines: 34 On Mon, 2006-09-04 at 12:50 +1000, Nigel Cunningham wrote: > I agree. The current limit varies widely, most often being 256 or 512, > but sometimes also 896 (s390!) or 1024 (arm, arm26, parisc) or 4096 > (uml). Would users and developers of those arches care to enlighten? Why > 896? Simple. Between 0x10480 and 0x10800 there are 0x380 bytes available. That makes 895 characters for the commandline. Completly obvious, how could you miss it ? ;-) The reason is our initial address space layout for the very first kernel images. Now it is hard to changed because the different ipl tools rely on the layout. We choose to add a few more bytes than 256 because on s390 we potentially have many devices. The dasd= parameter can really be big. -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin. -- VGER BF report: H 0 - 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/