Re: grub-probe fails to find PC partition due to Apple disklabel

[Chris Knadle]

On Monday 28 July 2008, Robert Millan wrote:
> On Mon, Jul 28, 2008 at 03:25:00PM -0400, Chris Knadle wrote:
> > On Monday 28 July 2008, Felix Zielcke wrote:
> > > Am Montag, den 28.07.2008, 14:41 -0400 schrieb Chris Knadle:
> > > >    However on the last test I did make an error and left out the -d
> > > > option to grub-probe, and that's required for the grub-probe to
> > > > succeed, so unfortunately the output I posted is erroneous.
> > > >    A new one is attached which has Robert's patch applied -- it does
> > > > succeed in finding the partition, but unfortunately we can't fix the
> > > > problem this way because I believe it makes Apple partition detection
> > > > *always* fail.
> > >
> > > Urgs, yeah didn't see that.
> > > You have to use -d if you give a device.
> > > Why do you think that with this it will always fail?
> >
> >    Because the test that the patch does is to check for an HFS+
> > filesystem magic number against the first 2 bytes on the drive, which
> > contains a jump vector for the Grub stage1 binary.  i.e. in order for the
> > test to pass, Grub has to be unbootable.
>
> My check has nothing to do with HFS+, it's based on the header magic number
> (0x4552), which differs from the partition magic (0x504D) but also from the
> HFS+ magic (0x482B, 0x4858).
>
> Please could you test it against an apple partmap?

   I just tested this on the iMac with a different HD and installing Debian 
Lenny Beta2 (since I couldn't find a download for Etch) -- took forever to do 
but turns out it was worth it -- your patch WORKS!  :-)  Congratulations.

   This also means I misunderstood several things.  I must have misread what 
exactly the 0x4552 magic number pertained to.  Ugh.

   Thanks very much for hanging in there and fixing this.

   -- Chris   

-- 

Chris Knadle
address@hidden