From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1Hzsrb-0008Rg-64 for mharc-grub-devel@gnu.org; Sun, 17 Jun 2007 07:24:11 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HzsrZ-0008RO-HD for grub-devel@gnu.org; Sun, 17 Jun 2007 07:24:09 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1HzsrX-0008RC-HV for grub-devel@gnu.org; Sun, 17 Jun 2007 07:24:09 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HzsrX-0008R9-DQ for grub-devel@gnu.org; Sun, 17 Jun 2007 07:24:07 -0400 Received: from khepri.openbios.org ([80.190.231.112]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1HzsrX-00083z-1G for grub-devel@gnu.org; Sun, 17 Jun 2007 07:24:07 -0400 Received: from stepan by khepri.openbios.org with local (Exim 4.67) (envelope-from ) id 1HzsrV-00018M-9o for grub-devel@gnu.org; Sun, 17 Jun 2007 13:24:05 +0200 Date: Sun, 17 Jun 2007 13:24:05 +0200 From: Stefan Reinauer To: The development of GRUB 2 Message-ID: <20070617112403.GA24100@coresystems.de> References: <20070616160553.C62C1BFD7@mail.lfs-matrix.net> <4675BFB0.4010902@cross-lfs.org> <87d4zvjuza.wl@dekkers.cx> <20070617092639.GA14818@aragorn> <20070617093715.GA18112@coresystems.de> <87bqfekfkw.wl@dekkers.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87bqfekfkw.wl@dekkers.cx> X-Operating-System: Linux 2.6.22-rc2-git7-43-default on an x86_64 User-Agent: Mutt/1.5.15 (2007-04-06) X-Duff: Orig. Duff, Duff Lite, Duff Dry, Duff Dark, Raspberry Duff, Lady Duff, Red Duff, Tartar Control Duff X-detected-kernel: Linux 2.6 (newer, 3) Subject: Re: 64 Bit Support? 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: Sun, 17 Jun 2007 11:24:10 -0000 * Jeroen Dekkers [070617 13:03]: > > Interesting would also be to boot pure 64bit kernels. I think some of > > the BSDs have their bootloader switch to 64bit long mode, so the kernel > > does not have to dot this anymore. Maybe grub could do the same thing. > > To enable long mode you have to enable paging and I don't think the > bootloader should be doing things like that. I also don't see any > problems with the OS enabling long mode. Yes, enabling long mode is overly complex and was not well designed, imho. So I partly agree. We considered enabling long mode in LinuxBIOS a while ago, to avoid the same "old cruft" situation like with 16bit BIOS and 32bit OS. But you can not enable long mode without a huge amount of overhead (ie. paging), so it can only be done when the RAM controller is enabled and RAM is working. By that time accessing 64bit address space has already become a lot less interesting for the boot firmware. So the next place where it would make sense at all is in the bootloader. The problem might be that Grub2 locks out existing operating systems, if it does not support switching to long mode itself. I read rumours only, so I might be completely wrong. Is anyone booting non-Linux OSes like FreeBSD, NetBSD, OpenBSD, OpenSolaris, etc with GRUB2 yet? Stefan -- coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br. Tel.: +49 761 7668825 • Fax: +49 761 7664613 Email: info@coresystems.de • http://www.coresystems.de/