From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754236Ab2FLVFs (ORCPT ); Tue, 12 Jun 2012 17:05:48 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45850 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752540Ab2FLVFr (ORCPT ); Tue, 12 Jun 2012 17:05:47 -0400 Message-ID: <4FD7AF24.8080607@zytor.com> Date: Tue, 12 Jun 2012 14:05:40 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Brandon Falk CC: linux-kernel@vger.kernel.org Subject: Re: [question] x86/x86_64 boot process References: In-Reply-To: X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12/2012 01:49 PM, Brandon Falk wrote: > Greetings. Please CC me on any responses as I do not subscribe to the list. > > I'm currently working on a very very small boot loader. Currently it > uses BIOS int 0x13 to load up the 'setup' segments to 0x9000:0x0000. I > jump to this location, set up the kernel options, and then jump to > 0x9020:0x0000. Everything goes great. However, I get the message 'No > setup signature found...'. I'm assuming this is due to not loading up > the protected-mode code. I'm slightly confused as to how the protected > mode code is to be loaded. As my 'bzImage' is 2.6MB, I would need to > raise the A20 line to possibly load this up. Does the kernel assist in > this process at all? Should I set up a code32_start routine for my > code to load up the kernel? Once I'm in protected mode, how will I > even access the medium that the kernel is loaded from without creating > a driver? > > Currently the medium is a floppy image loaded in VMWare. It's a 64-bit > system. I'm just looking to be pointed in the right direction for the > next step (and if my current steps are valid for Protocol 2.10). > > Here's the current code (the code is manually overwritten onto the > bzImage, however only the code... the headers are left intact on the > bzImage): > Please read Documentation/x86/boot.txt. -hpa