From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755981AbXIQPaX (ORCPT ); Mon, 17 Sep 2007 11:30:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753652AbXIQPaK (ORCPT ); Mon, 17 Sep 2007 11:30:10 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60486 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753611AbXIQPaI (ORCPT ); Mon, 17 Sep 2007 11:30:08 -0400 Message-ID: <46EE9D66.1030705@zytor.com> Date: Mon, 17 Sep 2007 08:29:42 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: "Huang, Ying" CC: Andi Kleen , "Eric W. Biederman" , akpm@linux-foundation.org, Yinghai Lu , Chandramouli Narayanan , linux-kernel@vger.kernel.org Subject: Re: [RFC -mm 2/2] i386/x86_64 boot: document for 32 bit boot protocol References: <1190017582.5866.22.camel@caritas-dev.intel.com> In-Reply-To: <1190017582.5866.22.camel@caritas-dev.intel.com> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Huang, Ying wrote: > This patch defines a 32-bit boot protocol and adds corresponding > document. > + > +In addition to read/modify/write kernel header of the zero page as > +that of 16-bit boot protocol, the boot loader should fill the > +following additional fields of the zero page too. > + > +Offset Type Description > +------ ---- ----------- > + 0 32 bytes struct screen_info, SCREEN_INFO > + ATTENTION, overlaps the following !!! > + 2 unsigned short EXT_MEM_K, extended memory size in Kb (from int 0x15) > + 0x20 unsigned short CL_MAGIC, commandline magic number (=0xA33F) > + 0x22 unsigned short CL_OFFSET, commandline offset > + Address of commandline is calculated: > + 0x90000 + contents of CL_OFFSET > + (only taken, when CL_MAGIC = 0xA33F) > + 0x40 20 bytes struct apm_bios_info, APM_BIOS_INFO > + 0x60 16 bytes Intel SpeedStep (IST) BIOS support information > + 0x80 16 bytes hd0-disk-parameter from intvector 0x41 > + 0x90 16 bytes hd1-disk-parameter from intvector 0x46 > + > + 0xa0 16 bytes System description table truncated to 16 bytes. > + ( struct sys_desc_table_struct ) > + 0xb0 - 0x13f Free. Add more parameters here if you really need them. > + 0x140- 0x1be EDID_INFO Video mode setup > + > +0x1c4 unsigned long EFI system table pointer > +0x1c8 unsigned long EFI memory descriptor size > +0x1cc unsigned long EFI memory descriptor version > +0x1d0 unsigned long EFI memory descriptor map pointer > +0x1d4 unsigned long EFI memory descriptor map size > +0x1e0 unsigned long ALT_MEM_K, alternative mem check, in Kb > +0x1e4 unsigned long Scratch field for the kernel setup code > +0x1e8 char number of entries in E820MAP (below) > +0x1e9 unsigned char number of entries in EDDBUF (below) > +0x1ea unsigned char number of entries in EDD_MBR_SIG_BUFFER (below) > +0x290 - 0x2cf EDD_MBR_SIG_BUFFER (edd.S) > +0x2d0 - 0xd00 E820MAP > +0xd00 - 0xeff EDDBUF (edd.S) for disk signature read sector > +0xd00 - 0xeeb EDDBUF (edd.S) for edd data > + > +After loading and setuping the zero page, the boot loader can load the > +32/64-bit kernel in the same way as that of 16-bit boot protocol. > + > +In 32-bit boot protocol, the kernel is started by jumping to the > +32-bit kernel entry point, which is the start address of loaded > +32/64-bit kernel. > + > +At entry, the CPU must be in 32-bit protected mode with paging > +disabled; the CS and DS must be 4G flat segments; %esi holds the base > +address of the "zero page"; %esp, %ebp, %edi should be zero. This is just replicating the "zero-page.txt" document, which can best be described as a "total lie" -- compare with the actual structure. -hpa