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hence why you would have the CSM

A CSM won't help windows recognise a GPT partition table. Remember, once the OS is past the bootstrap phase, it no longer uses the BIOS. Or at least it shouldn't since every BIOS call would incur 2 mode switches (PM -> real, and real -> PM).

Guys, the GPT can house a fake partition table of the old style to use with the CSM encapsulated within a GPT type partition. If he created a CSM with enough functionality, then it is possible that it might work.

Isn't the old partition table supposed to hold a single partition consisting of the entire disk? In which case, wouldn't using both tables be kinda hacky and not comform to specs?

I really don't understand why people would want to use Windows on a Mac...

for one my gba flasher doesnt work in OSX, and some people like OSX but need Windows for work or school

Isn't the old partition table supposed to hold a single partition consisting of the entire disk? In which case, wouldn't using both tables be kinda hacky and not comform to specs?

based on what aristotle-dude said, GPT was made to be compatible with older partition tables

edit: here i found this: http://www.microsoft.com/whdc/device/storage/GPT_FAQ.mspx

8. Can a disk be both GPT and MBR?

No. However, all GPT disks contain a Protective MBR.

9. What is a Protective MBR?

The Protective MBR, beginning in sector 0, precedes the GPT partition table on the disk. The MBR contains one type 0xEE partition that spans the disk.

10. Why does the GPT have a Protective MBR?

The Protective MBR protects GPT disks from previously released MBR disk tools such as Microsoft MS-DOS FDISK or Microsoft Windows NT Disk Administrator. These tools are not aware of GPT and do not know how to properly access a GPT disk. Legacy software that does not know about GPT interprets only the Protected MBR when it accesses a GPT disk. These tools will view a GPT disk as having a single encompassing (possibly unrecognized) partition by interpreting the Protected MBR, rather than mistaking the disk for one that is unpartitioned.

11. Why would a GPT-partitioned disk appear to have an MBR on it?

If this occurred, you must have used an MBR-only-aware disk tool to access the GPT disk. See answers #8 through #10, earlier.

Guys, the GPT can house a fake partition table of the old style to use with the CSM encapsulated within a GPT type partition. If he created a CSM with enough functionality, then it is possible that it might work.

Not likely.

The only way you're likely going to get dual-boot to work before the Macs go 64-bit (again) is to have 2 hard drives (one with GPT, one with MBR).

based on what aristotle-dude said, GPT was made to be compatible with older partition tables

The spec requires a protective MBR "wrapper" that prevents other tools from thinking it's a blank disk.

It is NOT designed for manipulation or use of any kind by tools, OSes, etc. So no, you aren't going to be able to use an MBR-only OS on a GPT drive.

I don't understand why people like these macbooks so much... I mean, even with the idea that you could run windows on it, you can still get better quality and style elsewhere... For example, sony vaio laptops are known for their style and sleekness, yet you don't see people obsessing over them all the time.

I don't understand why people like these macbooks so much... I mean, even with the idea that you could run windows on it, you can still get better quality and style elsewhere... For example, sony vaio laptops are known for their style and sleekness, yet you don't see people obsessing over them all the time.

they look great and they run OSX, something your sony laptop cant do legally

Yeah, but his Sony looks great and runs Windows, something your macbook can't do technologically :p

the world would be a better place without Windows, for years i hoped that MS would just scrap it and rewrite the OS from scratch and include an optional compatibility layer for "old" Win32 programs but it never happened and never will (the perfect time would have been after Win2k and ME

The spec requires a protective MBR "wrapper" that prevents other tools from thinking it's a blank disk.

It is NOT designed for manipulation or use of any kind by tools, OSes, etc. So no, you aren't going to be able to use an MBR-only OS on a GPT drive.

I've decided to read over the EFI specs about the GPT table and this made me think:

On all GUID Partition Table disks a Protective MBR (PMBR) in the first LBA of the disk precedes

the GUID Partition Table Header to maintain compatibility with existing tools that do not

understand GPT partition structures. The Protective MBR has the same format as a legacy MBR,

contains one partition entry of OS type 0xEE and reserves the entire space used on the disk by the

GPT partitions, including all headers. The Protective MBR that precedes a GUID Partition Table

Header is shown in Table 11-7. If the GPT partition is larger than a partition that can be

represented by a legacy MBR, values of all Fs must be used to signify that all space that can be

possibly reserved by the MBR is being reserved.

Provided the EFI firmware doesn't check the contents of the MBR entries, I guess you could have both. The first partition would use up the portion of the disk occupied by the GPT's partitions and the other partitions could use up whatever space is left. The restriction would be that the GPT and it's partitions would have to occupy space at the beginning of the disk. I still don't like this though and think it's hacky.

Does it even need to have GPT partitioning? Can't the BIOS compatibility layer just allow for booting from an old school-partitioned hard drive? I don't think that this would even hinder dual-booting since Mac OS X seems to run fine from BIOS-style partitions as shown by Mac OS X being hacked to run on PCs.

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