From owner-freebsd-cloud@freebsd.org Wed Apr 12 16:57:09 2017 Return-Path: Delivered-To: freebsd-cloud@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 52AD6D3BB74 for ; Wed, 12 Apr 2017 16:57:09 +0000 (UTC) (envelope-from julian@freebsd.org) Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "vps1.elischer.org", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 1235E3DD for ; Wed, 12 Apr 2017 16:57:08 +0000 (UTC) (envelope-from julian@freebsd.org) Received: from Julian-MBP3.local (106-68-194-141.dyn.iinet.net.au [106.68.194.141]) (authenticated bits=0) by vps1.elischer.org (8.15.2/8.15.2) with ESMTPSA id v3CGv2UI062489 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 12 Apr 2017 09:57:05 -0700 (PDT) (envelope-from julian@freebsd.org) Subject: Re: amazon/xen... any way at all to pass a message/signal/semaphoere/morse-code to the boot loader? To: Colin Percival , freebsd-cloud@freebsd.org References: <0100015b6070d24d-a23d7d90-11c0-4065-9bd0-0fc71b5874d6-000000@email.amazonses.com> <6f1c694d-1bb7-cdcc-daed-fd2e25dc2a28@freebsd.org> <0100015b61023e1a-decb3a7d-8856-40b0-a2ff-9e8057092254-000000@email.amazonses.com> From: Julian Elischer Message-ID: Date: Thu, 13 Apr 2017 00:56:56 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <0100015b61023e1a-decb3a7d-8856-40b0-a2ff-9e8057092254-000000@email.amazonses.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-cloud@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "FreeBSD on cloud platforms \(EC2, GCE, Azure, etc.\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Apr 2017 16:57:09 -0000 On 12/4/17 3:13 pm, Colin Percival wrote: > On 04/11/17 23:04, Julian Elischer wrote: >> On 12/4/17 12:34 pm, Colin Percival wrote: >>> [CCing freebsd-cloud, which is the right place for discussions of FreeBSD/EC2] >>> >>> On 04/11/17 21:03, Julian Elischer wrote: >>>> In Amazon ec2 they have no console access (though I heard rumors that it was >>>> available I have not seen any sign of it) so I'd like to put a "recovery >>>> partition" into an AMI. >>>> The trick is how to convince it to boot to that instead of the regular action. >>> Can you get what you want via gptboot's support for selecting the partition >>> to boot via "bootonce" and "bootme" flags? >> not if you can't get onto to the machine. > Well, I meant that you'd set this up in advance, so that if it can't boot the > normal partition it would automatically fall back to the recovery partition. > >>> Maybe you can repurpose some of the logic used for booting over NFS? I've >>> never heard of people booting over NFS when the initial bootstrap comes from >>> disk rather than PXE, but I assume it's possible...? >> Oh I've done it, in the past but you still have the same issue.. >> how do you signal the boot code to do this? >> >> (does an AMI have a bios capable of doing network operations?) I was thinking >> about whether we could add a really simple xn driver into the bootcode to allow >> us to have an console of sorts (accessible from an adjacent machine only??) > Oh, good point. No, the boot loader doesn't know anything about PV drivers, > and there's no emulation, so you can't do anything networky from the boot > loader. > I was thinking of a specialist AMI bootcode that could handle just an xn0 interface. I don't know enough about the xen drivers to know if that would even be possible.