From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1OyjRf-0003Y2-Qs for mharc-grub-devel@gnu.org; Thu, 23 Sep 2010 06:54:32 -0400 Received: from [140.186.70.92] (port=39567 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OyjRc-0003Wy-MV for grub-devel@gnu.org; Thu, 23 Sep 2010 06:54:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OyjRb-0005HQ-5a for grub-devel@gnu.org; Thu, 23 Sep 2010 06:54:28 -0400 Received: from smarthost01.mail.zen.net.uk ([212.23.3.140]:56913) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OyjRb-0005GQ-00 for grub-devel@gnu.org; Thu, 23 Sep 2010 06:54:27 -0400 Received: from [82.69.40.219] (helo=riva.pelham.vpn.ucam.org) by smarthost01.mail.zen.net.uk with esmtp (Exim 4.63) (envelope-from ) id 1OyjRY-0000Sd-KY for grub-devel@gnu.org; Thu, 23 Sep 2010 10:54:24 +0000 Received: from cjwatson by riva.pelham.vpn.ucam.org with local (Exim 3.36 #1 (Debian)) for grub-devel@gnu.org id 1OyjRX-0008PE-00; Thu, 23 Sep 2010 11:54:23 +0100 Date: Thu, 23 Sep 2010 11:54:23 +0100 From: Colin Watson To: The development of GNU GRUB Message-ID: <20100923105422.GS21862@riva.ucam.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-Originating-Smarthost01-IP: [82.69.40.219] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) Subject: Re: Booting 64-bit Linux on a Macbook5,2 X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Sep 2010 10:54:30 -0000 On Wed, Sep 22, 2010 at 03:16:24PM -0400, Patrick Doyle wrote: > I don't know where to turn here. It seems that every thread I've > found that describes this ends with "and now it works", but I can't > seem to get there. > > I have installed 64-bit Ubuntu 10.04 on a Macbook5,2. I would like to > boot this without the acpi=off parameter that is currently required. > Once, in the past, I installed grub-efi in the /efi folder and was > able to boot a 32-bit Ubuntu installation on this hardware. But I > have since installed the 64-bit version and can no longer get it to > boot. It gets as far as displaying the message about loading initrd > and stops there. Unlike on BIOS systems, on EFI systems the bit length of the kernel must match the bit length of the firmware (at least on Linux; Vladimir tells me that the XNU kernel in Darwin does some horrible things to work around this restriction). Thus there are two possibilities: 1) You have 32-bit EFI, and won't be able to boot a 64-bit kernel from it. 2) You have 64-bit EFI, and your previous 32-bit kernel was actually silently falling back to BIOS compatibility mode. In either case, I'd recommend trying an ordinary BIOS version of GRUB instead (i.e. the grub-pc package); you'll need to create a BIOS Boot Partition (http://grub.enbug.org/BIOS_Boot_Partition), install GRUB to that partition rather than to the MBR, and tell rEFIt to boot from that partition. -- Colin Watson [cjwatson@ubuntu.com]