From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1LnYhR-00060M-BT for mharc-grub-devel@gnu.org; Sat, 28 Mar 2009 09:35:49 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LnYhP-0005yG-M0 for grub-devel@gnu.org; Sat, 28 Mar 2009 09:35:47 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LnYhL-0005vj-6Z for grub-devel@gnu.org; Sat, 28 Mar 2009 09:35:47 -0400 Received: from [199.232.76.173] (port=55482 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LnYhL-0005vg-0r for grub-devel@gnu.org; Sat, 28 Mar 2009 09:35:43 -0400 Received: from aybabtu.com ([69.60.117.155]:50741) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LnYhK-0002FJ-Lq for grub-devel@gnu.org; Sat, 28 Mar 2009 09:35:42 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1LnYXQ-0005ov-7U for grub-devel@gnu.org; Sat, 28 Mar 2009 14:25:29 +0100 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1LnYhD-0002P7-6v for grub-devel@gnu.org; Sat, 28 Mar 2009 14:35:35 +0100 Date: Sat, 28 Mar 2009 14:35:35 +0100 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090328133535.GD8493@thorin> References: <49CAB717.2030900@freenet.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49CAB717.2030900@freenet.de> Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Subject: Re: grub2 vs. kexec X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 Mar 2009 13:35:47 -0000 On Wed, Mar 25, 2009 at 11:58:31PM +0100, Michael Reichenbach wrote: > With great interrest I was reading http://grub.enbug.org/GSoC/Ideas2009 > the new ideas sound really innovative. > > I see two possible approaches to implement such features. Either > - doing it the GRUB2 way or > - loading a linux kernel (which supports already all the stuff), loading > the needed drivers (bluetooth for menu, wlan and tcp/ip for network > booting) and use kexec to boot the the new kernel > > I mean you are going to implement almost a complete operating system > again for booting another operating system. At the same time there is > already a complete operating system (linux) which is also able to boot > another operating system (kexec). > > What is the advantage of the GRUB2 way? Actually, it's the other way around. GRUB is designed from scratch to be a bootloader. It can have many features, but that's not the important. When it comes to a bootloader, other things, such as being small/fast and having a reliable installation system are. We do realize GRUB is not an OS kernel, and it doesn't intend to be anything more than a temporary stage that can load kernels (Marco once joked about adding context switching and a scheduler, but it was just a joke ;-)). OTOH, this "kexec" idea strikes me as Linux trying to be a bootloader instead of a kernel [1]. Sure, it can be a bootloader if someone implements the missing things (a GUI, an installation system, etc), but it can't fit the purpose that well, since every single line of its code is designed with another idea in mind: "once we're running, we stay there". This just means they aim at different things. Which is good because in the end, the parts complement each other. [1] It's funny, it reminds me of EFI in the exact opposite situation :-) -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."