From owner-freebsd-stable@FreeBSD.ORG Mon Oct 6 17:37:00 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 150AA1065687 for ; Mon, 6 Oct 2008 17:37:00 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id DF3BB8FC22 for ; Mon, 6 Oct 2008 17:36:59 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [65.122.17.41]) by cyrus.watson.org (Postfix) with ESMTP id 6FABC46B0D; Mon, 6 Oct 2008 13:36:59 -0400 (EDT) Date: Mon, 6 Oct 2008 18:36:59 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: "Dr. Aharon Friedman" In-Reply-To: Message-ID: References: <363BDDAF-76C7-49AE-A8F5-EE1995C4CCBF@drsns.com> <6228eb140810060825g784d0d1fle6738d3186cc4451@mail.gmail.com> User-Agent: Alpine 1.10 (BSF 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-stable@freebsd.org, David Sanders Subject: Re: Is FreeBSD a suitable choice for a MacBook? --- WHY? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Oct 2008 17:37:00 -0000 On Mon, 6 Oct 2008, Dr. Aharon Friedman wrote: > Sorry, I meant BSD. > > Here is the link: > > http://www.freebsd.org/news/press-rel-3.html > > Aharon Friedman I don't see the origina message you replied to on the list, so am replying to it via your post... >> I'm just a lurker, but even I know that only some of the userland apps in >> OS X are BSD-based. The kernel is mach microkernel based and not even >> slightly similar. This claim regarding the kernel is highly inaccurate. There are significant quantities of FreeBSD, Mach, and Apple-originated code in the Mac OS X kernel, both because Apple pulled in a lot of FreeBSD code early on, but also because code moves between the two kernels fairly easily and fairly frequently, and in both directions. You'll find a FreeBSD-derived VFS, network stack, and countless other kernel parts in Mac OS X from their first open source drop forward. More recently, though, you'll find that the Audit implementation present in FreeBSD 6.x and later is based on the Mac OS X kernel audit code, and the TrustedBSD MAC Framework that appeared in Mac OS X Leopard is straight from FreeBSD. It's certainly true that there's a lot of non-FreeBSD code -- XNU uses the Mach scheduler and Mach IPC, and a quite different driver framework, for example. There's also some convergent evolution: FreeBSD contains a Mach-derived VM that also comes from the original Mach project. Finally, just to be clear: XNU is not a micro-kernel, even though it contains significant amounts of Mach code. The "microkernel" and remainder of the kernel run in a single address space, and although certain separation is (often) maintained in the source code / abstractions, the Mach, FreeBSD, and device driver parts run in a unified and tightly integrated way. Robert N M Watson Computer Laboratory University of Cambridge