I got really frustrated with triple boot on Max OS X Lion. At one point I had it
working on snow leopard pretty well. After many frustrating hours spent trying to get it
setup I sold my MBA on eBay then bought a hp dm1 4050. The HP is much faster and now I can
boot Linux and windows much easier plus I walked away with $300 in cash. My buddy who
works for Apple has told me that the installation of refit voids the warranty and they
have refused to fix computers under warranty with refit installed. I think this is bummer
because the Apple hardware is good, it makes no sense why Apple cares. After I read snobs
biography, where he dose not even mention open source despite the large amount of open
source software used by Apple I decided I would switch back to a pc based laptop. I do
still like the iPad but that is a different story.....
Sent from my iPad
On Dec 25, 2011, at 3:22 PM, Chris Murphy <lists(a)colorremedies.com> wrote:
Responding to my own email on various boot behaviors, with some
EFI vs CSM-BIOS:
EFI boot produces highly variable results between Apple models, while CSM-BIOS boot is
very consistent between Apple models.
Windows 7 will not boot in UEFI mode on Apple hardware. I have searched thoroughly and
have found no success stories so far. Even if it has been done, it's outside of what
normal people are willing or able to do. Yet CSM-BIOS booting works fine on all of
Apple's hardware for the past 4-5 years. This makes some sense, because Microsoft says
they explicitly support UEFI 2.x and higher only, while Apple's firmware is based on
Intel EFI 1.10, not UEFI 2.x.
CSM-BIOS boot is not ideal. But it's also not ideal to support a flakey EFI boot
scenario that may take a lot of effort for low efficacy.
Also consider Mac users are running into the BIOS-MBR 2.2TB limit on Apple hardware. It
stands to reason Apple will need to make some modifications to their EFI implementation to
deal with this eventually. This accommodation of Windows (U)EFI requirements may be good
for linux, or may be bad for linux. I think investing in Apple EFI unknowns is risky.
Further, consider CSM-BIOS has the best chance of supporting Fedora when Apple releases
new hardware. It may take months or years to support the peculiarities of each model's
So if I were voting, I'd suggest a constrained type of support for CSM-BIOS boot,
both Fedora only (atypical) and dual boot (typical).
This is possible, I've done it with several combinations, but it's non-trivial. I
question if gptsync is at all appropriate for making sure the resulting hybrid MBR and GPT
aren't a disaster (more often than not gptsync produces ill advised hybrid MBRs, more
so than they already are).
The big gotcha with triple boot support, is that the most common situation is the
existence of Mac OS and Windows, which means there is a hybrid MBR and GPT. This means a
Fedora installation must make sure both an appropriate MBR and GPT are produced not merely
so that all three systems to boot as expected, but to ensure neither of the previously
working systems become unbootable. Today this is not the case with Fedora 16.
Anaconda+parted blow away such a hybrid MBR in favor of GPT only with protective MBR, the
result of which is an unbootable Windows (Mac OS remains bootable).
Even refusing to install Fedora (or a warning about the consequences) would be a much
needed improvement here.
A bit about Apple's philosophy:
Apple doesn't sell hardware. They don't sell operating systems. They sell an
experience that combines both. That's how they see it. The two are inseparable.
At best they "tolerate" Windows support, and not just any Windows, only Windows
7 is supported for the better part of a year now. I have zero doubt they'd be baffled
by the idea anyone would want to run linux on a Mac, and would not care one single bit if
it could not be done with either EFI or CSM-BOOT modes.
This is the hallmark company that does not believe users have any right to boot an
operating system of their choice on any hardware they produce. People who buy Apple
hardware today cannot even run the most recent previous version of Mac OS 10.6.8 (released
July 28 2011) - it simply won't boot on their hardware.
I am leery of excessive amounts of effort, which in effect is a kind of turd polishing,
to deal with Apple's non-standard EFI. I don't like being relegated to CSM-BIOS
mode booting, but it does work, with well understood limitations.
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