MacBookPro3,1 + Snow Leopard = 32 bits.

Oh, come on. It's so much fun. They twist themselves in knots then start throwing feces like the monkey cage. You just got to know when to get out of the room.

The file "mach_kernel" in the root directory is the one containing the core of the kernel. Its name is derived from the Mach microkernel, which in reality is only a part of the OSX kernel (XNU).

Can I assume you know the derivation of XNU & how that applies here?

Nick 1066 wrote:
The MacBookPro 3,1 should be capable of running the 64 bit kernel but it's not on the list.

Core2duo = 64 bit
Santa Rosa chipset = 64 bit (I have 4GB and it can use it all)

Yet with the 6+4 key press, the Boot.plist and nvram modifications this will not boot into 64 bit kernel.

What NVRAM command did you use?
My 3.1 box boots fine into the 64-bit kernel with the proper NVRAM command.
Check this article
http://yourmacguy.wordpress.com/2009/08/24/boot-snow-leopard-64-bit/

R C-R wrote:

The file "mach_kernel" in the root directory is the one containing the core of the kernel. Its name is derived from the Mach microkernel, which in reality is only a part of the OSX kernel (XNU).

Can I assume you know the derivation of XNU & how that applies here?

It depends on what you mean with "derivation". If for derivation of it you mean "XNU = X is Not Unix", yes I know about it. But that's just an acronym. X may not be Unix (what's X anyhow? X window like X11?), but XNU (or better Darwin) is.

One of the major problems on discussing about OSX is that it has far too many definitions:

- It's based on the microkernel Mach
- The kernel is not actually a microkernel because it's Mach with FreeBSD (and OpenBSD like NextStep?) extensions. That would make it an hybrid kernel
- It's kernel it's called XNU
- OSX is commercial name for the OS but the real (Unix) name is Darwin
- Or maybe OSX is Darwin + Finder + Aqua + Cocoa + whatever.

In other words OSX is built taking pieces from here and there, making the whole identification pretty confusing. Still, that's irrelevant in this discussion.

What's relevant is that no matter the OS or the kernel the process of bootstrapping (i.e loading the kernel and transfer the execution to it) is similar in any architecture. Thus, the answer to your question:

"so, all kernels are the same??" is

"no, but they all bootstrap in more or less the same way".

Which is the main reason why PCs with BIOS (32bits) can effectively load (and run) OSX (with k64) even if they are not designed for it.

For future reference you may check: http://en.wikipedia.org/wiki/Booting#Boot_loader

Don't worry. Wikipedia is very good when regarding technical subjects. As you said there is no the need to rediscover the wheel every time.

OSX is commercial name for the OS but the real (Unix) name is Darwin

It is extraordinarily simplistic statements like this one that make it impossible to have a meaningful discussion with you. Darwin is only a part of OS X, so what you are saying here is that a part of something is really the same thing as the whole of it. Whether the subject is OS X or anything else, that isn't true. Sometimes that doesn't matter. Here it matters a great deal, at least if you want more than a superficial understanding of OS X & how it differs from other OS's.

More to the point, XNU is not just a clever acronym. From Mac Dev Center: Porting UNIX/Linux Applications to Mac OS X: Glossary (emphasis added):

" XNU The Mac OS X kernel. The acronym stands for X is Not Unix. _XNU combines the functionality of Mach and BSD with the I/O Kit, the driver model for Mac OS X_."

I/O Kit is not, as you incorrectly deduced from yet another overly superficial examination of the topic, simply an SDK. It is also a fundamental part of the OS X kernel (XNU), providing the abstract object model for drivers. This is by no means irrelevant to the boot process. In particular, it is not true that "the process of bootstrapping (i.e loading the kernel and transfer the execution to it) is similar in any architecture," at least beyond a superficial level. I cannot believe that you would not know know this if you studied the "*BootX, boot.efi, and System Initialization*" section of the Mac Dev Center: System Startup Programming Topics: The Boot Process link.

Off & on, I have hoped that we could move this discussion beyond vague generalities to something that might benefit both of us (& anybody else following along that might contribute something material to the topic). But as of now, it seems about the only thing we agree on is that a major problem for this kind of discussion is a lack of precise definitions of terms that would reduce confusion. Yet, when I do go into detail about such things, you complain that I needlessly complicate things, & constantly respond with statements that seem designed to obscure or dismiss significant differences among OS's as irrelevant.

Whatever your reasons are for that, it doesn't seem to me that you are interested in looking for answers if superficialities are inadequate for the task. Since I disagree strongly about that, I don't know if we have anything further to discuss.

I think I also wrote "Or maybe OSX is Darwin + Finder + Aqua + Cocoa + whatever". What I wanted to stress is that the basic OS is Darwin, which is an Unix system.

Regarding the I/O kit you wrote that it is the one enabling or loading the device drivers and that was totally wrong. Basically I/O Kit consists on 3 libraries, of which 1 is the real framework, IOKit.framework. But it gives the definitions and the tools to develop device drivers. It's like the interface between them and the kernel itself as a whole.

But anyway, you're right. This discussion is not productive for me anymore. I learned an **** of a lot about hackintoshes, blessing boot loaders, EFI32 vs EFI64 and all stuff like that during my investigations. So much that I'm pretty sure I could build a Snow Leopard 64 bit compatibe PC tomorrow if I'd like. Still I have to understand why Netkas claims that it is possible to boot a Mac from Chameleon 2 with PC EFI on a USB drive. I couldn't find any way to do it.

What it is clear is that anyone saying that the SL 32 bits limitation of many Macs is due to technical constraints and not just an Apple decision has been proved completely wrong.

The real analogy is not between bicycles and motorbikes. It's more like with sport cars in USA and in Europe. In USA they have a restriction (in the injectors I think) that limit the top speed. Like the Snow Leopard black list.

Michelasso wrote:
I think I also wrote "Or maybe OSX is Darwin + Finder + Aqua + Cocoa + whatever".

You wrote lots of things that demonstrate that you don't know much about Mac OS X & apparently have no interest in learning about it beyond a superficial level. If you think that is sufficient to achieve your goals, I wish you luck. You are going to need it.

But anyway, you're right. This discussion is not productive for me anymore. I learned an **** of a lot about hackintoshes, blessing boot loaders, EFI32 vs EFI64 and all stuff like that during my investigations.....

yeah dude... i moved on to the os x86 community, because there are people with a greater knowledge about the OS itself than our friend rcr here provides and those people are trying to help you out and not continuously trying to distract you with bulls... . because they simply aren't apple advocates like you find them here...

and when everything's getting down somehow start whining about your dead mother... i mean.. come on... seriously??

kaosdroid wrote:

yeah dude... i moved on to the os x86 community, because there are people with a greater knowledge about the OS itself than our friend rcr here provides and those people are trying to help you out and not continuously trying to distract you with bulls... . because they simply aren't apple advocates like you find them here...

Don't forget the Linux community. Now there is Grub-EFI boot loader (64 bits as well) for Macs. For once it works (only) with my Macbook 2,1 (and minis). My biggest problem is to be able to boot legacy systems (like Chameleon for the Hackintosh) from the USB. I already installed rEFIt in my main partition but it doesn't do the job. What I'm thinking is to use a stack like this (bottom to top):

Hard Disk:
rEFIt
Grub- EFI

USB
Chameleon with PCEFI v1.01/1.03

I give it small chances, but I'll test it also because I want to find a way to boot the Win7 RC install image from the USB!! That's driving me crazy as well. I thought the Macs could use any type of file system when booting from the USB but I'm afraid that is not the case. I looked everywhere in Internet.

Did you find anything useful by any chance?

actually I would think that rEFIt would do the job...
I just remember to have it used on leopard (booting the image from a usb iPod which
wasn't possible by the firmware boot loader.. only firewire would work!)
and i also use rEFIt to boot linux... but not the image and not from usb
I also downloaded chameleon but haven't tried it yet... this weekend i am busy like ****
next week i will give it a try...

R C-R wrote:

Michelasso wrote:
I think I also wrote "Or maybe OSX is Darwin + Finder + Aqua + Cocoa + whatever".

You wrote lots of things that demonstrate that you don't know much about Mac OS X & apparently have no interest in learning about it beyond a superficial level. If you think that is sufficient to achieve your goals, I wish you luck. You are going to need it.

I mist this one. Actually, Sir, I have the feeling that the one whom is not much into Unix here is not me. I have been working on Unix servers for nearly 20 years now as I anticipated since my first post in this thread. I also have a Master in CS, when, without offense, I wonder if you followed any CS/IT University class at all. I may not be specialized in OSX but the concepts behind it are more or less the same like in any Unix system. Its first one is "simplicity". It's part of the Unix philosophy and that's the reason why Unix systems are not such a mess like Windows.

I'd like also to remind that in another thread you have been the one saying that my solution for downgrading to Snow Leopard couldn't work. So much that I had to test it and prove you wrong (as usual).

Nope. The EFI recognizes all HFS USB boot devices. I have an USB pendrive where I "restore" the image of the DVD install disks with Disk Utility and then I install OSX from it pressing option. I works straightforward and I've read it works well with the iPods as well. You can even install rEFIt on an USB flash drive and boot rEFIt from it.

That's why I'm pretty frustrated that I'm not able to make it booting legacy systems. Well, it seems that it simply can't. That's why the Linux people developed Grub-EFI (or Grub 2) after all. The problem is that Grub-EFI will be able to boot from the USB only a special EFI installation image of Ubuntu if I understood correctly. But since I've plenty of time to mess up it won't cost me too much to give it a try. At least it's confirmed Grub-EFI will work on my MacBook. What's interesting is that Grub-EFI has an option in the config file to load the "appleloader USB". Check:

http://grub.enbug.org/TestingOnMacbook

I hope that will work at least for Windows 7. It would be great if it works with Chameleon+PCEFI as well even if I'm starting to believe that Netkas wrote something not right about it). The best option would be to be able to put our hands on the source code of SL boot.efi, remove the checks for unsupported systems, recompile it, install and bless it and reboot. Not a chance I suppose.

I may not be specialized in OSX but the concepts behind it are more or less the same like in any Unix system.

It is the "more or less" part that I don't think you understand as well as you might find useful in achieving your goals. OS X is significantly different from other UNIX-like OS's in several ways, not the least of which is how the kernel environment is created at boot time, especially in how drivers are loaded & linked to the kernel.

XNU is not just K32 or K64. It currently combines the Mach 3.0 kernel, components of BSD derived from FreeBSD, & the I/O Kit device driver framework. Device drivers may operate in user or kernel space. During the boot process, some classes of drivers must be loaded & linked into kernel space for the boot process to complete. This process is described in some detail in the Mac Dev Center Boot Process topic. From that reference it should be obvious that I/O Kit is not an SDK, although one exists for it.

Neither is OS X just Darwin: Darwin is the open source part of the OS; however, it also contains proprietary, closed source parts. In some cases Apple provides Darwin API's for outside use as approximate equivalents of its private ones but does not use them itself. You can usually get an idea of the source (BSD, Darwin, whatever) from the last line of associated man pages for anything Apple publicly documents.

IOW, just like the acronym says, OS X is not UNIX. It is certainly a UNIX- like OS, but the "less same" parts are significant here, enough so that they need to be taken into account when creating a viable 64-bit kernel boot strategy for Macs for which Apple does not provide a ready-made one.

IOW, just like the acronym says, OS X is not UNIX.

dude.. you aren't seriously saying this... right? that is now really really rough...