From owner-freebsd-questions@FreeBSD.ORG Sat Dec 22 20:08:39 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0ADD516A41A for ; Sat, 22 Dec 2007 20:08:39 +0000 (UTC) (envelope-from jrisom@gmail.com) Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.176]) by mx1.freebsd.org (Postfix) with ESMTP id CF15213C442 for ; Sat, 22 Dec 2007 20:08:38 +0000 (UTC) (envelope-from jrisom@gmail.com) Received: by py-out-1112.google.com with SMTP id u77so1874935pyb.3 for ; Sat, 22 Dec 2007 12:08:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:in-reply-to:references:mime-version:content-type:message-id:content-transfer-encoding:cc:from:subject:date:to:x-mailer; bh=9hnwj8ebNAGeH1CeX3B6Xvu337i92HZDf/Tn+RfPfrE=; b=IHppGprBESvVma4TZTJdnTVEDIBqJj5HL7ywXEZaAAtKLqWk/MDANJ5S1WH8vac+mbpMrL/79O4Ssm97FlfVGdajaKfn8K0fOaKQOAhfYP5zKeCgBsexgmRD/3ar1mMBvtu4+CAuv4OYk8trdYmxtPY/3q9iR6ogXfidQNsn+xc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=in-reply-to:references:mime-version:content-type:message-id:content-transfer-encoding:cc:from:subject:date:to:x-mailer; b=JJvlRlItcRjp5pMaFIfgAcN4krrcFsAgaRE9kvSYOnteaO6eQB3Gxji/ZuI5fu8n0ipvz9iAjB7hI2GLb4o8GdA6d8v1Wj8PxOkDueq6ZckKSvE9LU8ch8MmvElw9m0nLe11daWluuTIgsi96d4q+x8ODIXLEjIqM2zMoC1fHlE= Received: by 10.35.131.13 with SMTP id i13mr3162442pyn.50.1198354117064; Sat, 22 Dec 2007 12:08:37 -0800 (PST) Received: from ?192.168.1.7? ( [74.134.230.123]) by mx.google.com with ESMTPS id n45sm4514125pyh.37.2007.12.22.12.08.34 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 22 Dec 2007 12:08:35 -0800 (PST) In-Reply-To: <476CD9C9.3090101@cran.org.uk> References: <70f41ba20712211547g74a6a4b0tf08fec8125739a08@mail.gmail.com> <476CD9C9.3090101@cran.org.uk> Mime-Version: 1.0 (Apple Message framework v624) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <020f211f77887eeb2eb8a03cd825f372@gmail.com> Content-Transfer-Encoding: 7bit From: Joshua Isom Date: Sat, 22 Dec 2007 14:09:14 -0600 To: Bruce Cran X-Mailer: Apple Mail (2.624) Cc: freebsd-questions@freebsd.org Subject: Re: amd64 native boot loader? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Dec 2007 20:08:39 -0000 On Dec 22, 2007, at 3:32 AM, Bruce Cran wrote: > AMD64 CPUs are backwards compatible with i386; they boot in 16-bit > real mode and only get switched into 64-bit 'long mode' by the kernel > later on. Since both i386 and amd64 start booting in the same way, > there's no need for separate bootloaders. > > -- > Bruce > I've thought about this too, but do wonder why the boot loader couldn't go into long mode in one of the loader stages. I don't know if there'd be any significant improvements or drawbacks other than duplication of some code(which I imagine isn't changed often). Somewhat offhand, can the OpenBSD loader chain boot FreeBSD? Due to my dvd drive being sata over atapi, it wasn't recognized by the 6 branch until recently(many thanks to whoever committed the change). But I recall that the boot cd for FreeBSD wouldn't boot, but the boot cd for OpenBSD would. Of course that does primarily relate to cdboot and not boot0.