From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 076E667B91 for ; Sat, 11 Feb 2006 10:54:45 +1100 (EST) Date: Fri, 10 Feb 2006 17:46:10 -0600 (CST) From: Kumar Gala To: atul.sabharwal@exgate.tek.com Subject: RE: kernel startup In-Reply-To: <4A062D477D842B4C8FC48EA5AF2D41F201BA207A@us-bv-m23.global.tektronix.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > > Normally is it the uboot that uncompresses the kernel or the kernel > uncompress itself? > > >>How would something compressed uncompress itself? If u-boot is being > used > >>it will uncompress a compressed kernel and put the image at physical > 0. > > Small correction. Just like a self extracting binary, a kernel can have > a decompression code prepended to the start of kernel which can > decompress the > Kernel. This is how redboot for xscale is structured or syslinux /lilo > for x86. This also happens with the boot wrapper that is in arch/{ppc,powerpc}/boot > > Although u-boot has simplified this step by doing the CRC checksum of > the > uiMage header as well as data and also decompress the kernel. Based on > load > address, entry point, the kernel can start executing. > > Now, whether cache is enable or not, MMU is enabled/disabled depends on > the > Developer. In current u-boot, the MMU is not used. I-Cache is On and > D-cache > is off. I'm not sure what sub-arch we are talking about, but some do have the MMU on. - kumar