From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1H6jPk-0007rM-0k for mharc-grub-devel@gnu.org; Tue, 16 Jan 2007 03:11:28 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1H6jPi-0007ql-Nf for grub-devel@gnu.org; Tue, 16 Jan 2007 03:11:26 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1H6jPg-0007pb-RH for grub-devel@gnu.org; Tue, 16 Jan 2007 03:11:26 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1H6jPg-0007pU-Np for grub-devel@gnu.org; Tue, 16 Jan 2007 03:11:24 -0500 Received: from [213.165.64.20] (helo=mail.gmx.net) by monty-python.gnu.org with smtp (Exim 4.52) id 1H6jPg-0003mZ-7m for grub-devel@gnu.org; Tue, 16 Jan 2007 03:11:24 -0500 Received: (qmail invoked by alias); 16 Jan 2007 08:11:22 -0000 Received: from dslb-084-060-030-199.pools.arcor-ip.net (EHLO [192.168.128.11]) [84.60.30.199] by mail.gmx.net (mp054) with SMTP; 16 Jan 2007 09:11:22 +0100 X-Authenticated: #733973 Message-ID: <45AC88AB.4040308@gmx.de> Date: Tue, 16 Jan 2007 09:11:23 +0100 From: "Jan C. Kleinsorge" User-Agent: Thunderbird 1.5.0.9 (X11/20070103) MIME-Version: 1.0 To: The development of GRUB 2 References: <45AC1401.2050503@flexible-solutions.de> In-Reply-To: <45AC1401.2050503@flexible-solutions.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Subject: Re: Starting a kernel out of a running kernel... 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: Tue, 16 Jan 2007 08:11:26 -0000 Volker Jung wrote: > Hello, > > is there a solution for starting a new Linux kernel out of a running > Linux kernel using GRUB or a changed GRUB? First I thought I could use > LILO. But LILO runs in real mode, not having any idea about protected > mode. GRUB runs in protected mode itself - in order to boot an OS it > has to switch back to real mode or to prepare the protected mode > control registers of the CPU to start the OS. So GRUB may be able to > pass control from one kernel to the other. > > The idea: Instead of using GRUBs abilities to do various things inside > a shell one could use it to boot a complete Linux. Then one can do > everything one wants and afterwards one could start the desired system > WITHOUT rebooting. > > Perhaps this sounds crazy but there is a problem where this idea would > be helpful: So you could implement a read only failsafe system that > starts again whenever you reset your remote server and out of this > system (remotely controlled via SSH or similar) you could start the > desired system WITHOUT having to reboot which would again start the > failsafe system which isn't the thing one wants. You can call this > "GRUB with a fully featured OS"... > > In LILO this behaviour could be implemented using the -R option - but > this assumes a read write medium... > > Any suggestions? That is not possible. 'Protected Mode' clearly denotes some form of protection. Unless you grant the software extra privileges (that is, write kernel-code) it's virtually impossible. Apropos 'virtually': Use some virtualization technology instead and you never will have to reboot any machine again, ever. > > Thanks in advance > Volker > > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel > -jan