From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from jade.aracnet.com (jade.aracnet.com [216.99.193.136]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 0AA29DDF6E for ; Thu, 3 May 2007 01:56:26 +1000 (EST) Received: from [192.168.0.4] (216-99-213-225.dsl.aracnet.com [216.99.213.225]) (authenticated bits=0) by jade.aracnet.com (8.13.6/8.12.8) with ESMTP id l42FnUmU009548 for ; Wed, 2 May 2007 08:49:30 -0700 Message-ID: <4638B319.6080005@BitWagon.com> Date: Wed, 02 May 2007 08:49:45 -0700 From: John Reiser MIME-Version: 1.0 To: linuxppc-embedded@ozlabs.org Subject: better compression: 1.0MB for defconfig-minimal kernel Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , upx --lzma compresses much tighter than gzip. A user-mode test jig succesfully handles the 2.6.21.1 kernel configured with defconfig-minimal in 1,018,237 bytes total, in contrast to the 1,390,765 bytes of vmlinux.bin.gz (and the .gz does not include 34,795 bytes for compiled arch/powerpc/boot/*.c.) However, I cannot figure out how to get a real bootable kernel that uses compression. I'd like to test it on an Apple PowerMac G4 that now runs Fedora Core 6. The FC6 kernel calls itself "vmlinuz" but does _not_ use any compression; I double-checked by rebuilding from the .src.rpm. A plain "make" in a kernel.org-2.6.21.1 tree gives a vmlinux that is not compressed. A "make zImage" produces arch/powerpc/boot/uImage [with no thanks to the *undocumented* mkimage] that uses gzip, but does not use any code from arch/powerpc/boot/*.c; so where is the decompression code? linux/Documentation/powerpc/*.txt does not shed light on these issues. Please point me at a description of the flow of control for building and booting a compressed Linux kernel for powerpc. Thank you. --