Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753625AbZCIKAv (ORCPT ); Mon, 9 Mar 2009 06:00:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752796AbZCIKAm (ORCPT ); Mon, 9 Mar 2009 06:00:42 -0400 Received: from ti-out-0910.google.com ([209.85.142.184]:22566 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752733AbZCIKAl (ORCPT ); Mon, 9 Mar 2009 06:00:41 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=gBxPEOmM1eBhykrw0b8LhB+Vbgpsd9tle6bi8fqZcWUqOZDVN5Tpscnefsg3kM8yW7 T45rTL41j5Duql07td3t5s6a6mskWZ72+krUUEs2awyc6H5GAflr2dkodklRMP1kKjO+ nce9dWK77JIhjMHSsAYWdf8ZoT2hHYTpiEL94= MIME-Version: 1.0 In-Reply-To: <2d05c4580903090243k6cf73ee9ubb6c4fccf0f07a2f@mail.gmail.com> References: <2d05c4580903090243k6cf73ee9ubb6c4fccf0f07a2f@mail.gmail.com> Date: Mon, 9 Mar 2009 18:00:35 +0800 Message-ID: Subject: Re: Linux* Processor Microcode Data File From: Jike Song To: Dragoslav Zaric Cc: LKML 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 Content-Length: 1798 Lines: 51 On Mon, Mar 9, 2009 at 5:43 PM, Dragoslav Zaric wrote: > Hello, > > I was browsing Intel web site for my processor docs and I bumped > on download link "Linux* Processor Microcode Data File" and it says > there: > > "The microcode data file contains the latest microcode definitions for > all Intel processors. > Intel releases microcode updates to correct processor behavior as > documented in the respective > processor specification updates. While the regular approach to getting > this microcode update is via > a BIOS upgrade, Intel realizes that this can be an administrative > hassle. The Linux Operating System > and VMware ESX products have a mechanism to update the microcode after > booting. For example, > this file will be used by the operating system mechanism if the file > is placed in the /etc/firmware > directory of the Linux system." > > So, does new kernel versions just copy this microcode update file in > /etc/firmware folder or new > instructions are replaced in assembly code ? > Linux provides an microcode driver for Intel & AMD CPUs: arch/x86/kernel/microcode_* and there is a service called "microcode_ctl" to open it and write the microcode on every starting. Where to find the microcode data is this service specified, and the kernel doesn't care it. You may want to find: http://www.urbanmyth.org/microcode/ > new instructions are replaced in assembly code ? As far as I can tell, no. The microcode only only change the CPU's behavior, not the assembler. -- Thanks, Jike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/