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blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
Hi
I've tried holding 6 and 4 keys, and editing boot plist file and still no 64 bit mode. I can run windows 7 64 bits just fine, even my hackintosh can run snow leopard in 64 bits why can't my macbook?
 

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Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
582
Finland
Some MacBook can't boot into 64-bit mode OS X. There is NO need to boot into 64-bit in OS X, you won't see ANY difference. 64-bit thing isn't same in OS X as it is in Windows so there is no RAM limits and 32-bit kernel can run 64-bit apps.

Use MRoogle and you'll find more about it but don't worry, you ain't missing anything
 
Feb 15, 2009
5,486
2
Boston, MA
Apple blocks all MacBook's from booting into 64-bit mode. There are some EFI firmware hacks out there though.

Like the previous poster said, you will not notice any difference in 64-bit mode unless you use 32 GB+ of RAM. 64-bit mode was designed for servers and MAYBE Mac Pro's.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
582
Finland

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
Because it's kinda stupid having apple blocking features, and snow leopard in 32 bits supports more than 4gb of ram? That's odd, anyway that hack no longer works maybe apple changed something in boot.efi but still boots:p
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
582
Finland
Because it's kinda stupid having apple blocking features, and snow leopard in 32 bits supports more than 4gb of ram? That's odd, anyway that hack no longer works maybe apple changed something in boot.efi but still boots:p

The RAM limit is Windows only. Even Tiger supported +4GB RAM. I don't why why there is a limit in Windows but it doesn't apply to OS X. As said above, 64-bit kernel ain't gonna speed up unless your drivers are all 64-bit and you need +32GB RAM which in your case, isn't even possible
 

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
The RAM limit is Windows only. Even Tiger supported +4GB RAM. I don't why why there is a limit in Windows but it doesn't apply to OS X. As said above, 64-bit kernel ain't gonna speed up unless your drivers are all 64-bit and you need +32GB RAM which in your case, isn't even possible

Well I've messed around with the boot.efi file and now I have it running at 64 bits mode, but your right, like linux had an option when compiling the kernel to support more than 4gb in 32 bit mode. Anyway it works in 64 bit mode so far so good, no diference in performance, just for fun:D

If anyone wants the boot.efi modified file just ask:)
 

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bestestever

macrumors newbie
Nov 22, 2010
26
0
Well I've messed around with the boot.efi file and now I have it running at 64 bits mode, but your right, like linux had an option when compiling the kernel to support more than 4gb in 32 bit mode. Anyway it works in 64 bit mode so far so good, no diference in performance, just for fun:D

If anyone wants the boot.efi modified file just ask:)

Hey i would LOVE to have that boot.efi file!!!
plzzz
plzz
 

vistadude

macrumors 65816
Jan 3, 2010
1,423
1
There are some scientific programs that take advantage of 64 bit mode, and they run faster even with only a few GB's of RAM. It's kind of a shame that apple blocks us to 32 bit mode.
 

iThinkergoiMac

macrumors 68030
Jan 20, 2010
2,664
4
Terra
There are some scientific programs that take advantage of 64 bit mode, and they run faster even with only a few GB's of RAM. It's kind of a shame that apple blocks us to 32 bit mode.

But those programs don't require a 64-bit kernel. They will still run just fine in 64-bit mode on a 32-bit kernel. Don't complain unless you know what you're complaining about (especially when, if you'd read the whole thread, you'd know what I just said) ;)

64-bit kernel simply allows the kernel itself to address more memory. The catch is, unless it's figuring out much much more memory than a MacBook can hold, there's no point. The idea is to give the kernel more memory to store what it needs to store in order to work with managing the RAM. But unless you've got something like 64 GB RAM, the kernel doesn't need access to more than 4 GB RAM for itself. That's all that booting the 64-bit kernel does. Practically everything else 64-bit works just find with the 32-bit kernel.
 

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
Hey i would LOVE to have that boot.efi file!!!
plzzz
plzz

Let me find it and I will re upload it:D

Edit: What macbook do you have? because boot.efi had a few changes since 10.6.5 and it needs to be re modified.
Boot Efi
I've uploaded the old version because my harddrive crashed just now (damn seagate again). My macbook is still in repairs so test and report back.
 
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bestestever

macrumors newbie
Nov 22, 2010
26
0
Let me find it and I will re upload it:D

Edit: What macbook do you have? because boot.efi had a few changes since 10.6.5 and it needs to be re modified.
Boot Efi
I've uploaded the old version because my harddrive crashed just now (damn seagate again). My macbook is still in repairs so test and report back.

I have macbook 7,1 (newest)
10.6.5

I will test and report back.
 

vistadude

macrumors 65816
Jan 3, 2010
1,423
1
Well I have no idea what a kernal is, but I know that when I want to edit 50+ megapixel images (not photos), I can't do a FFT on a 32 bit mac but I can on a 64 bit mac... What gives? We're talking about 2-4 GB ram, which should easily handle it.

But those programs don't require a 64-bit kernel. They will still run just fine in 64-bit mode on a 32-bit kernel. Don't complain unless you know what you're complaining about (especially when, if you'd read the whole thread, you'd know what I just said) ;)

64-bit kernel simply allows the kernel itself to address more memory. The catch is, unless it's figuring out much much more memory than a MacBook can hold, there's no point. The idea is to give the kernel more memory to store what it needs to store in order to work with managing the RAM. But unless you've got something like 64 GB RAM, the kernel doesn't need access to more than 4 GB RAM for itself. That's all that booting the 64-bit kernel does. Practically everything else 64-bit works just find with the 32-bit kernel.
 

iThinkergoiMac

macrumors 68030
Jan 20, 2010
2,664
4
Terra
Well I have no idea what a kernal is, but I know that when I want to edit 50+ megapixel images (not photos), I can't do a FFT on a 32 bit mac but I can on a 64 bit mac... What gives? We're talking about 2-4 GB ram, which should easily handle it.

A 32-bit only Mac vs a 64-bit capable Mac is an entirely different question than a 32-bit kernel vs a 64-bit kernel. The kernel is, more or less, the brain of your OS. That is, of course, an extraordinarily simplified explanation but it'll do.

A 32-bit only Mac would either be one of the PowerPC Macs (excluding G5s) or a 1st generation Intel Mac. Any of those computers is going to be significantly slower than a 64-bit capable Mac. So not only are you possibly missing out on some RAM, you're also using a Mac that's just plain slower than any 64-bit Mac.
 

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
These macbooks fully support 64-bit (6,1 and 7,1) they even have EFI64. Apple just locks us out of the fun:mad:.
I still don't get it why the hell they locked us out of 64-bit.
I don't have my macbook for testing. And changing boot.efi in an hackintosh does nothing so guess I will have to wait for the macbook to return:p

Edit: can somebody try this? http://www.easy-share.com/1913081511/boot_mod_6_5.zip
Don't forget to change the apple.boot.plist thingy
 
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blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
I've made an simple script to replace the boot.efi file. And at least for me with an 6,1 macbook I've got 64 bits:D

I've uploaded an screenshot. I don't know if I can upload the modded file here so I've uploaded it elsewhere.
http://www.megaupload.com/?d=D812BKL8

You must extract the zip file. Go to terminal, change the directory to the extracted directory with the script. Then do a "sudo -s" type your password and then "./patch.sh".
 

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joe48

macrumors newbie
Feb 8, 2011
3
0
@Blackburn, Can you PM me. I would like to get some info from you offline on hints for customizing a 10.6.3 boot.efi to enable 64 bit kernel on a macmini3,1 , and maybe a macbook5,1 (13" unibody, not pro). I am no stranger to x86 assembly, hex editors, etc., but am hoping I can get this done without blowing too much time.

I need 64 bit kernel for software testing. I am not real happy about the prospect of handing Apple more cash to get hardware that is nearly identical to what I already have.
 

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
I don't really understand much of debugging intel (x86) code. And has far as I remember, theres a kind of table on the boot.efi file, and for each family something had to be changed. But I changed them all, so probably it will work for you. Sadly I still don't have my macbook fixed and I'm finishing my exams :(

Anyway you can read more here http://netkas.org/?p=189 the comments do have some interesting info too.
But if your mac mini doesn't have the 64 bits efi bootrom no dice.

You can check if your boot rom is 64 bits by typing this command in terminal:
ioreg -l -p IODeviceTree | grep firmware-abi
 

joe48

macrumors newbie
Feb 8, 2011
3
0
@Blackburn, I got it working on my macmini3,1 running 10.6.5 . I assume it will also work on my 13" macbook unibody, but I am still happy with 10.5.8 on that system.

The boot.efi patch I used is different, but I am not 100% sure yours would not have worked. I suspect one of the '4's would need to be a '3'.

It would be nice if someone disassembled the boot.efi, found the code that did the compare, and patched over it with nops. It would be nice to have a single patch that worked for all the blacklisted systems.
 

blackburn

macrumors 6502a
Original poster
Feb 16, 2010
974
0
Where Judas lost it's boots.
Well my exams are over and I've poked around the boot.efi.

So far I've got almost nothing:( Anyway I found this:

-> Looks like it was some kind of header.

-> If I remove the header IDA recognizes it as a 64bit PE file (can't do anything with it), if not it recognizes another 32bit PE file (I'm using the free version).

-> I suppose that if your efi is an 32 bit one it loads the second pe image, else it loads the first pe image.

-> Since it doesn't have a checksum (let's hope that apple doesn't get creative) we could try to replace the 32 bit pe image with the 64 bit one and see what happens. But since most 32 bit machines don't have 64 bit drivers (old macbooks) it's not much use.

-> And for an assembly expert shouldn't be difficult to patch the function that checks the model id (IDA even draws a nice map, and splits functions).

-> Since the model check is in the 64 PE part, unless I find an 64 pe disassembler I can't do much with it. And by the looks of it models with and 32 bit efi don't even check the model they just boot the 32 bit kernel, *maybe* someone could patch it to boot the 64 bit kernel (not sure if it's possible, read somewhere that it is).
 
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joe48

macrumors newbie
Feb 8, 2011
3
0
Once the boot.efi is broken down to a PE file, it might be possible to disassemble it with dumpbin.exe from the Windows SDK. This is not going to be as useful as IDA pro, but it might be enough.

When I have done this sort of thing in the past I have used a debugger, but debuggers are tricky with boot time code.
 
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