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On Wed, May 29, 2013, at 04:25 AM, Andrea Conti wrote: |
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> >> We can't have more then 4 primary partitions on a hard disk. |
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> >> |
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> >> Gentoo needs 2 partitions, /boot and a Virtual partition (that count's |
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> >> as well as one primary) with all the other folders. |
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> >> |
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> >> Windows will create 2. and Mac OSX minimum 1, am I right?! |
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> >> |
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> > |
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> > Your Windows partitions have to be in the first four, but OSX and linux |
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> > partitions can be anywhere thanks to the gpt partition table. |
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> |
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> Things are both simpler and more complex than that. |
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> |
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> The real problem is that while rEFIt/rEFInd, OSX and Linux have no |
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> problem dealing with a GPT partition table, Windows only supports MBR. |
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> (Windows 7+ supports GPT partition tables but it can only boot from a |
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> GPT disk in EFI mode. On a Mac OSes other than OSX must be booted in |
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> BIOS emulation mode, therefore the requirement for MBR on the system |
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> disk for Windows still stands). |
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> |
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> GPT and MBR, however, are only indexing schemes: they describe how many |
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> partitions are on a disk and their location, but apart from providing a |
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> high level 'type' label they have nothing to do with what's inside a |
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> partition. |
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> |
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> GPT-partitioned disks traditionallly have what's called a 'protective |
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> MBR', i.e. a dummy MBR which defines a single partition of type 0xEE |
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> spanning the whole disk; this is intended to keep partitioning tools |
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> that are not GPT-aware from considering the disk uninitialized and |
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> inadvertently destroying its contents. |
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> However, nothing prevents you from adding to the protective MBR regular |
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> entries for some of the partitions, and have the disk look like a |
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> 'normal' MBR disk as far as those partitions are concerned. |
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> |
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> The result is called a 'hybrid MBR' and it's the main trick behind Boot |
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> Camp. There is really nothing special about booting (or installing) |
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> Windows on a Mac: it just works, as long as you have both a properly set |
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> up hybrid MBR with an entry for the Windows partition and a suitable EFI |
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> boot manager. |
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> |
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> The former can be done with a tool such as gpt-fdisk (you can easily |
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> find a binary package for OSX, and there are directions for dealing with |
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> hybrid MBRs on the author's site); rEFInd is your best option for the |
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> latter. The standard Apple boot manager will also do, if you only need |
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> to boot OSX and Windows. |
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> |
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> Booting Linux works in a similar fashion. You don't even need a |
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> GPT-aware bootloader: good old GRUB 1 is perfectly up to the task, as |
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> long as there is an entry for its boot partition in the hybrid MBR. Then |
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> you can load a kernel with GPT support, and from there it's just a |
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> standard multiboot setup. |
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> |
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> HTH, |
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> andrea |
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|
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Thanks Andrea. I had though that the MBR was automatically mapped to |
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the the first 4 gpt partitions because that's they way it's always been |
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on my system. So now I wonder how it's been set that way, because I |
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know i've never touched gpt-fdisk and I didn't use bootcamp. Maybe the |
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refit installer. |
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