From owner-freebsd-current@freebsd.org Tue Dec 19 17:58:14 2017 Return-Path: Delivered-To: freebsd-current@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 1CEACE94052 for ; Tue, 19 Dec 2017 17:58:14 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: from asp.reflexion.net (outbound-mail-210-95.reflexion.net [208.70.210.95]) (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 C05BE2FAD for ; Tue, 19 Dec 2017 17:58:12 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: (qmail 24447 invoked from network); 19 Dec 2017 17:58:06 -0000 Received: from unknown (HELO mail-cs-02.app.dca.reflexion.local) (10.81.19.2) by 0 (rfx-qmail) with SMTP; 19 Dec 2017 17:58:06 -0000 Received: by mail-cs-02.app.dca.reflexion.local (Reflexion email security v8.40.3) with SMTP; Tue, 19 Dec 2017 12:58:06 -0500 (EST) Received: (qmail 8626 invoked from network); 19 Dec 2017 17:58:05 -0000 Received: from unknown (HELO iron2.pdx.net) (69.64.224.71) by 0 (rfx-qmail) with (AES256-SHA encrypted) SMTP; 19 Dec 2017 17:58:05 -0000 Received: from [192.168.1.25] (c-76-115-7-162.hsd1.or.comcast.net [76.115.7.162]) by iron2.pdx.net (Postfix) with ESMTPSA id 393F7EC943C; Tue, 19 Dec 2017 09:58:05 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: UEFI booting survey From: Mark Millard In-Reply-To: Date: Tue, 19 Dec 2017 09:58:04 -0800 Cc: FreeBSD Current Content-Transfer-Encoding: quoted-printable Message-Id: References: <60C20606-853E-43AE-9F90-44C65026A098@dsl-only.net> To: Warner Losh X-Mailer: Apple Mail (2.3273) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Dec 2017 17:58:14 -0000 On 2017-Dec-18, at 2:37 PM, Warner Losh wrote: > . . . >=20 > Or the following pseudo-code with all the weird special cases removed = for clarity >=20 > load loader.efi from ESP > if BootXXXX uefi variable holds a second path, use that for = root/kernel > otherwise if an override variable holds a kernel/root path, use that > otherwise scan for a usable ZFS pool, use that if it exists > otherwise use the same partition loader.efi was booted from for = root/kernel if it's usable > otherwise use the first UFS partition on the ESP that's usable. >=20 > A partition is usable if /boot/loader.rc exists on that path. What will be the role of /etc/fstab in establishing were the kernel is loaded from? Where world is loaded from? Where/how does use of /etc/fstab for specifying the root file system mount fit in the above pseudo-code? (For my particular interest the context uses UFS, not ZFS.) > What is being deleted is one final step: "otherwise use the first UFS = partition on any drive in a random order that's usable." which used to = be at the end of the boot1.efi psuedo code. It's my belief that no such = installations actually use this due to the random factor today (plug in = a new USB drive and it might take over). If my belief is wrong, it's my = belief that efibootmgr will solve it, and failing that, the fallback = mechanism (for platforms that use u-boot + EFI where UEFI variables = don't work) will allow the two or three people that are doing this = today. =3D=3D=3D Mark Millard markmi at dsl-only.net