From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759556AbXGOXGR (ORCPT ); Sun, 15 Jul 2007 19:06:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754562AbXGOXGG (ORCPT ); Sun, 15 Jul 2007 19:06:06 -0400 Received: from emailhub.stusta.mhn.de ([141.84.69.5]:34147 "EHLO mailhub.stusta.mhn.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754488AbXGOXGF (ORCPT ); Sun, 15 Jul 2007 19:06:05 -0400 Date: Mon, 16 Jul 2007 01:05:24 +0200 From: Adrian Bunk To: Jonathan Campbell Cc: linux-kernel@vger.kernel.org, torvalds@transmeta.com Subject: Re: Patches for REALLY TINY 386 kernels Message-ID: <20070715230524.GL3565@stusta.de> References: <469A8AED.7070207@nerdgrounds.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <469A8AED.7070207@nerdgrounds.com> User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 15, 2007 at 02:00:29PM -0700, Jonathan Campbell wrote: > I wrote a set of patches out of concern that even if you compile a 386 > kernel a lot of code irrelevent to legacy machines still remains. Things > like the Pentium TSC register, DMI information, ESCD parsing, and the use > of CPUID do not apply to these machines, but looking at System.map you can > see they're still there. > > Already with these patches I can compile a zImage kernel that is 450kb > large (890kb decompressed) with a small initramfs payload, floppy and > kernel module support, FPU emulation, that can successfully boot on an > ancient 386 laptop with only 1MB of extended memory. Eventually what I'd > like to have is the ability to compile a pure 386 kernel with all non-386 > functions removed (and perhaps the same for 486 machines). >... Besides some issues with the patch itself you didn't provide the one important number: By how much does your patch decrease the size of the kernel? Also note that when aiming for a tiny kernel enabling module support is a huge mistake since it increases the amount of RAM used when running the kernel by at about 10%. cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed