Re: Booting 64-bit Linux on a Macbook5,2

[Colin Watson]

On Thu, Sep 23, 2010 at 09:47:44AM -0400, Patrick Doyle wrote:
> Thank you for the reply.  I am able to boot either the 32-bit or the
> 64-bit kernel via grub when it is installed in /dev/sda3 (my Linux
> partition).  But I have to set acpi=off (or maxcpus=1) in order to
> boot the kernel.  (This is a known issue, see
> https://bugzilla.kernel.org/show_bug.cgi?id=13170 and
> https://bugs.launchpad.net/acpi/+bug/341230).  However as I've been
> reading around, it seems that some folks have been able to boot with
> full capabilities (i.e. ACPI and both cores) when booting via EFI.

I'm afraid I don't know how you might do that.  The best way to find out
why your system is hanging at boot is to attach a serial console to it,
if you can, and boot it with console=ttyS0 so that you can see the early
console messages.

> I've compiled a 64-bit version of grub and can bring up boot menus
> with that, but things hang when I attempt to launch the kernel.  I've
> tried both 32 and 64 bit kernels (full installations, actually) as
> well as ext2 and ext4 root file systems.  Nothing I try seems to be
> able to reproduce what I thought I saw work once before.

To me it sounds as if your machine has 64-bit EFI but that for some
reason the 64-bit kernel oopses at boot, before the console comes up.
I've seen this before and a serial console is about the only practical
way to debug it.

> I've tried compiling grub trunk with platform=efi, fetched with bzr,
> but the compile failed.  (I don't have my computer in front of me
> right now, so I can't tell you exactly what failed -- I'll double
> check that, unless that was to be expected).

It should work now; things were in flux over the last few days in the
run-up to the 1.99 freeze.

> Can you tell me if 1.98 supports ext4?  I've seen some (older) web
> pages that claim that it doesn't.  It would be nice to eliminate one
> variable from consideration.

Yes - those web pages are wrong.  They're probably just confused by the
fact that GRUB's 'ext2' module supports all of ext2, ext3, and ext4.

> This might not be the correct forum to ask this, but does anybody know
> what installing the "grub-efi-amd64" package really does for Ubuntu?
> Does it replace the grub-pc package that was presumably installed off
> the CD?

On Ubuntu 10.04 LTS, grub-efi-amd64 installs the files but you have to
install the actual boot loader yourself.  On Ubuntu 10.10, it should
install the boot loader as well.  In both cases, it conflicts with
grub-pc - you can only have one or the other installed at once.

> Should I be using that instead of compiling my own version of
> grub-1.98 (in a VMware box on my Mac) and placing my own version in
> /efi/grub?

Well, it would probably at least save you compiling it.

> Should I expect to install grub-efi-amd64 in /dev/sda3 and be able to
> boot directly from that?

There are instructions for EFI installation on the GRUB wiki
(grub.enbug.org), or the version of grub-install in Ubuntu 10.10 (or for
that matter in quite recent GRUB trunk) should do it automatically.

-- 
Colin Watson                                       address@hidden