Boot from logical partition (chainload method)

[elfuego]

Hi!

After some googling I got to the thread posted here which almost perfectly describes my problem:
http://forum.voodooprojects.org/index.php/topic,481.15.html

I didnt want to necro the thread, so the question is, how do I set up a chainloader in grub so that the OSX boots from a logical partition correctly? Better yet, if there is grub already installed and FreeBCD is the way to go - how do I set it up?

Problem description (for the ones bored with reading an old thread)
The fact is, I have triple boot Win 7, Ubuntu 10.04 and OSX all neatly nested under GRUB 2. Everything is bootable, except that OSX boots in a 'crippled' way (no EFI, no DSDT etc). So I found a solution here:
http://jeffhoogland.blogspot.com/2011/04/howto-chainload-grub2-into-chameleon.html
which describes a way to chainload chameleon.

That could work, as I found out, *IF* I had installed OSX on a primary partition, which I didnt. OSX is together with ubuntu under an extended partition as a logical partition. I can boot it perfectly well with iBoot. So... how can I make things work without a complete, fresh reinstall and without an iBoot CD for help?

Thanks!

[dmazar]

probably too late for you, but ...

you may try to use chain0 instead of boot0. it seems that chain0 scans extended partitions for HFS partition. boot0 does not.

[oldnapalm]

Copy Chameleon's "boot" file to the root of Mac OS partition and add in /etc/grub.d/40_custom

Code: [Select]

menuentry "Mac OS X Chameleon" {
         insmod hfsplus
         set root=(hd0,X) # X = Mac OS partition number
         multiboot /boot
}
then run update-grub.

It works with extended partition.

If you don't want to see Chameleon's menu, add in boot.plist

Code: [Select]

   <key>Quiet Boot</key>
   <string>Yes</string>
   <key>Default Partition</key>
   <string>hd(0,X)</string>


[elfuego]

Its never too late. I tried chain0 but it displays chainload error... 

...However, the solution by oldnapalm works flawlessly! Thanks a bunch, I still cant believe it works - but the fact is, Im posting from Snowy thanks to you!