From owner-freebsd-sysinstall@freebsd.org Wed Aug 23 11:19:26 2017 Return-Path: Delivered-To: freebsd-sysinstall@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 09865DE4566 for ; Wed, 23 Aug 2017 11:19:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id EB5906BC2D for ; Wed, 23 Aug 2017 11:19:25 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v7NBJPWZ042505 for ; Wed, 23 Aug 2017 11:19:25 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-sysinstall@FreeBSD.org Subject: [Bug 221674] Installer can't back up when it finds MBR Date: Wed, 23 Aug 2017 11:19:25 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: conf X-Bugzilla-Version: 11.1-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: scratch65535@att.net X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-sysinstall@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-sysinstall@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Sysinstall Work List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Aug 2017 11:19:26 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D221674 --- Comment #5 from MMacD --- (In reply to Nathan Whitehorn from comment #4) "It's one installer, the issue is that it has no idea if the machine has CS= M or not. You can't know that unless you booted CSM. " I apologise if this is a dopey question, but I've never had occasion to loo= k at specific load-and-go problems. Despite being comfortable with assembly languages, my interests have always been up at the human end (not surprisin= g, perhaps, in someone trained as a psychologist). My mental model of what's going on is that the bios (or equivalent) spins up the cd drive (or equivalent), loads the primary boot, and jumps to its well-known start address, carrying on from there. I.e., it's at least a somewhat agnostic operation at that point, capable of going down either of = two paths. Why wouldn't that be a good place to add somebody who could take a diagnost= ic look at the disc and present something like my menu suggestion? Such code would have the same access as any later code for doing low-level reads in a= id of figuring out what's on the disc. Again: apologies if this is a dopey question, and I'd be happy in that case= to be clued up if you feel you can take the time. --=20 You are receiving this mail because: You are the assignee for the bug.=