Re: grub-efi with latest mac mini

[Chris Murphy]

On Jun 8, 2012, at 1:18 PM, Vladimir 'φ-coder/phcoder' Serbinenko wrote:

> It doesn't mean that it's forced, more of unpopular.

It's forced if you want firmware updates.


> 
>> 
>>> Also Mac OS doesn't use EFI system partition other than
>>> for firmware updates.
>> 
>> Unclear. All Apple computers with Mac OS X running, have an identical 
>> Firmware.scap file installed to the EFI System partition.
> 
> Ok, idk what this file is for.

I'm thinking it's CSM related because it contains references to BIOS.


> 
>>> You mix again 2 things: you can boot in BIOS mode (CSM) on pure GPT as
>>> well. Windows is an exception since Microsoft pretends that possible is
>>> impossible.
>> 
>> False. Apple's CSM will not activate unless the following three things are 
>> true:
> 
> Have you tried to forcibly activate it with appleloader GRUB command?

You mean from GRUB2-EFI? No. If you mean GRUB2 (for BIOS), I get nowhere near 
GRUB if any of those three things are not true. Apple's EFI simply fails to see 
the disk as valid for anything other than Mac OS X, or totally invalid if there 
is no Mac OS X.

It seems the sequence is Apple's EFI scans the disk for those three things, and 
only then activates the CSM, which then executes the first 440 bytes of the 
MBR. I don't know if the CSM has a dependency on an active flag or not, or if 
it just blindly executes those 440 bytes.

Chris Murphy