Re: EFI-dualbooting OSX and Linux on iMac with T7400-CPU

[Eeri Kask]

bibo,mao wrote:
>> menuentry "MacOSX" {
>>   set root=(hd0,2)
>>   chainloader /System/Library/CoreServices/boot.efi
>> }
>>
>> menuentry "GNU/Linux" {
>>   set root=(hd0,5)
>>   linux /boot/vmlinuz root=/dev/sda5
>> }
>>
> There is no initrd option in your menu, I do not know whether it can
> successfully boot up without initrd option with grub2. you can enter
> into rescue mode(command-line mode), and enter commands like this:
> $linux /boot/vmlinuz root=/dev/sda5
> $initrd /boot/xxx
> $boot
> 
> And what is your linux kernel version?

2.6.18.5.

initrd is in my case in fact not needed;  I compiled ata_piix and ext3
drivers, and everything inbetween directly into the kernel, so if
correctly loaded, it should be able to access /dev/sda5 and retrieve
/sbin/init from the hard disk; then everything else comes from there as
well.

Currently I am a little puzzled, as grub2 loads and executes MacOS-X
boot.efi correctly, but if trying linux, then linux stops somewhere.
As next, if burning the same kernel image as a bootable syslinux-CD,
linux gets loaded and executed as one would expect.
With the "nv" driver even X11 runs in full 1920x1200 resolution on
iMac-T7400 excellently  (nvidia proprietary driver builds, starts and
runs without complaints, but shows "black pixels" only :-).

Maybe MacOS if booting from CD sets up some faked BIOS environment so
Linux and X11 are in believing it is usual IBM-PC-hardware, but if
booting with grub2 this is not the case and then linux fails?

Momentarily I am not convinced it is a grub2 issue.

Greetings,

    Eeri Kask