Pure efi dual boot macbook! I need some help!

[MaJac]

Hi community, I need some help to install gentoo linux on my Macbook (model 4,1 - late 2008 - Processor 2.1 GHz
Intel Core 2 Duo T8100).

What I'd like to do is to set up a dual boot system with Mac Os X 10.7 (that is already installed) and Gentoo but I have some issues with the bootloader. I would like to boot the system in pure efi mode (without rEFIt or anything BIOS simulation) just using GRUB 2. I followed the gentoo handbook (x86) and when I arrived at the chapter 10 (Configuring the bootloader) I moved to this three wiki pages:

1 - http://en.gentoo-wiki.com/wiki/Grub2
2 - http://dev.gentoo.org/~scarabeus/grub-2-guide.xml
3 - http://en.gentoo-wiki.com/wiki/EFI_Native_on_Mac

This is my partition scheme:

sda1 - EFI System Partition (fat32) (boot)
sda2 - Mac OS X Partition (hfs+)
sda3 - Recovery Mac OS X Partition (hfs+)
sda4 - Data Mac Os X Partition (hfs+)
sda5 - Swap Gentoo Partition (swap)
sda6 - Root Gentoo Partition (ext3)

Here are my questions and my doubt:

- When I emerge grub2 from portage I need to emerge it with "GRUB_PLATFORMS=efi-64" or with "GRUB_PLATFORMS=efi-32" (in my first try I emerge it with efi-32 support because with the efi-64 flag I reported some emerge error).

- After that I run "grub2-mkconfig -o /boot/grub2/grub.cfg" to generate the grub.cfg file in /boot/grub2 directory, I checked it and it seems to be correct (as for root partition and kernel directory). Then I run "grub2-install --no-floppy /dev/sda" to install grub 2 into my EFI partition (that reported installation done without error) and I reboot my system but it boot into mac os x without starting grub. So I reboot it agin into gentoo live cd and after chroot again I try another way... I run "grub-mkimage -d . -O i386-efi -o grub.efi part_gpt hfsplus fat ext2 normal chain boot configfile linux" to make a grub.efi executable and I move it to the EFI partition with th grub.cfg file. I reboot agin holding alt key and from the menu I choose to boot the partition with the grub.efi file but I get this error: "Missing Operating System"

Anyone have some suggestions or could me help to find a tutorial or a post where there is a procedure to dual boot this systems with grub2??


Thanks,

MaJac

[MaJac]

Ok, just a little up to say that finnaly i found a way to do it!

I reinstall gentoo (now for amd64 arch), then I successful emerge grub2 and with grub2-mkimage I make a grub.efi file, I move it into a folder in the mac os x partition and I bless it! It works fine, it loads gentoo but now I have some problem trying to configure grub2 to boot mac os x, any suggestions?

Currently I found a temporary solution: I moved grub.efi into another hfs partition and i bless it, so when I boot holding alt (option key) I can choose if boot from the mac os X partition or from the other hfs partition.

[MaJac]

Ok, last daily update with this grub2 menu entry my Macbook finally boot Mac Os X and Gentoo from Grub2 without rEFIt or anything else BIOS emulation:


menuentry "Mac OS X"{
insmod part_gpt
insmod hfsplus
root=(hd0,gpt2)
chainloader (hd0,gpt2)/usr/standalone/i386/boot.efi
}


the last "problem" is that in early GRUB2 startup I get this error: "prefix is not set", this error stay on the screen for just a sec, then grub2 start normally, any suggestions to fix it???

Thanks