[Fedora-livecd-list] Mac (EFI) USB booting

[Jeremy Katz]

On Monday, January 19 2009, Daire Byrne said:
> ----- "Jeremy Katz" <katzj at redhat.com> wrote:
> > For the x86 based Macs, it can work, but it's definitely far from
> > just working everywhere right now.  The first question is if your machine
> > is 32bit or 64bit EFI as we require matching x86 vs x86_64,
> > respectively, based on that.  Most of the original Core Duo stuff is 32bit EFI, the
> > newer is 64bit.  If you're using a 64bit EFI machine, right now,
> > you're out of luck -- the kernel even in Fedora 10 was broken with 64bit EFI
> > :(
> 
> Yes I saw that. Like I said I'd just be happy to even get one of my Macs to recognise the USB drive as a boot device at this point! I suppose I should test on a new MacBook too for completeness. I would have thought the Mac Mini should work though as that is x86_64 and has the Core Duo 2.

If it's a Core Duo 2, then it's _probably_ 64bit EFI -- so try with the
x86_64 Fedora 10 live image and I think it should at least be able to
bring up grub.  
 
> > I never managed to get rEFIt to boot off of an MBR-based USB device.
> > Some people said they did, but I have no clue what they did to do so
> > :)
> 
> I found the same kind of confusion too - some say it can be done others say it can't. To be honest booting a MBR USB stick on Mac is still probably the best way to go because the 3D gfx for ATI/Nvidia doesn't work under EFI atm. I think I'm going to have to try booting of a CD just for the GRUB/SysLinux boot and then mount the USB stick after the kernel boots up and the initrd scripts begin.

If you can find a way to consistently get an MBR USB stick to boot, I'd
love to help improve the docs there as I agree, it would certainly be
the "best" thing.  

One thing you can do is make a boot cd that has just the isolinux bits
and then points to a USB stick for the rootfs just by changing the root=
and rootfstype= arguments in isolinux.cfg.  I have done that with no
problems a number of times

Jeremy