From owner-freebsd-hackers@FreeBSD.ORG Sat Sep 9 15:04:57 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1D71C16A40F for ; Sat, 9 Sep 2006 15:04:57 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1249B43D5A for ; Sat, 9 Sep 2006 15:04:52 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id A935646C7C; Sat, 9 Sep 2006 11:04:51 -0400 (EDT) Date: Sat, 9 Sep 2006 16:04:51 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Erik Trulsson In-Reply-To: <20060906233245.GA23592@owl.midgard.homeip.net> Message-ID: <20060909160249.F87517@fledge.watson.org> References: <2699850609061520wad7f0f2s7b402fb7789336ff@mail.gmail.com> <20060906233245.GA23592@owl.midgard.homeip.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-hackers@freebsd.org, Eder Subject: Re: The nature of kernel of the FreeBSD X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Sep 2006 15:04:57 -0000 On Thu, 7 Sep 2006, Erik Trulsson wrote: > On Wed, Sep 06, 2006 at 07:20:39PM -0300, Eder wrote: >> A doubt, >> >> Kernel of the FreeBSD is monolithic, correct !!! > > Correct. > >> The MacOS is derived from kernel of the FreeBSD, correct !!! > > Incorrect. The kernel of MacOS X is mainly derived from the Mach kernel, > not from FreeBSD. I believe it also contains much code from various > BSD-derivatives (including FreeBSD) but the basic design is that of Mach > rather than that of BSD. I think that is a poor characterization. The vast majority of code in the Mac OS X kernel is device driver code in IOKit, which is from neither BSD nor Mach. Mach provides the VM and IPC, but it's hrad to argue that the architecture of the Mac OS X is the Mach architecture, because it's not a micro-kernel , and the kernel does not aspire to be one. The major visible/complex services in the kernel, both file system and network stack, are very BSD, and are directly derived from FreeBSD. I think it's reasonable to argue that Mac OS X is significantly influenced, both in architecture and code, by both Mach and BSD, but pretty inaccurate to state that it adopts one architecture over the other -- it really adopts both. Robert N M Watson Computer Laboratory University of Cambridge