Unlocking 64-bit efi Macbooks for 64-bit kernel.

Amit Singh recently made a post about patching boot.efi for 64-bit support on macbooks(with 64-bit efi).

Here is simplified version of his post:

To run 64-bit kernel on any mac with 64-bit efi you need patched boot.efi file

You can find file named boot64.efi here

It enables 64-bit kernel support for some macmini/macbook/imac/macbookair models, which has 64-bit efi bootrom.

Download file to desktop, open and run these commands

cd ~/Desktop

sudo cp boot64.efi /System/Library/CoreServices/

cd /System/Library/CoreServices/

sudo chown root:wheel boot64.efi

sudo chflags uchg boot64.efi

sudo bless −−folder /System/Library/CoreServices/ \
−−file /System/Library/CoreServices/boot64.efi

Commands starting with sudo will ask you for your password.

Next step – add arch=x86_64 to file /Library/Preferences/SystemConfiguration/ to Kernels Flags section

For example:

<key>Kernel Flags</key>

Now reboot, your mac should boot 64-bit kernel, but some models missing 64-bit intel video drivers, for example macbook4,1 with gmax3100, so only internal display will work, without qe/ci/opengl.

if something goes wrong, boot leopard/snowleopard dvd (or another installed osx system) and run this command in terminal

sudo bless –folder /Volumes/YOUVOLUMENAME/System/Library/CoreServices \
–file /Volumes/YOUVOLUMENAME/System/Library/CoreServices/boot.efi

p.s. if you have 32-bit efi, this commands will make no effect for you at all.


  1. T
    September 4th, 2011 | 2:47 am

    Installed both the x64 patch and x3100 x64 patch for macbook 4,1 on Lion and it does show 64 enabled, however I too cannot change the brightness of my screen now. The keys works, but the illumination does not change. Thank you for your work swegen.

  2. T
    September 4th, 2011 | 9:08 pm

    actually ALL of the power settings are not working. Closing the lid never spins down the hard drive or anything, and so the battery just drains until the computer shuts off. I checked terminal and all the pmsettings are the same as before. Is there a pmsettings series that needs to be 64bit as well?

  3. martin
    September 9th, 2011 | 1:50 pm

    Hi, great that a patch finally works so easily for my 3,1, just want to check if the Intel GMA X3100 64-bit kexts files are still needed? Also wondering if the 3,1 running in 64bit with it’s 800mhz bus speed will accept 4gb 800mhz memory? so it can be boosted to 8gb

  4. swegen
    September 21st, 2011 | 9:32 am

    I tested the 64-bit kernel with Snow Leopard 10.6.2 with MacBook3,1. Even when using all those 64-bit kexts there were problems.

    Results: Brightness keys respond, but brightness won’t change. When closing the lid it goes to sleep. But when coming back from sleep the display stays off so it need a reboot.

    Seems that Apple didn’t finish the 64-bit kexts for older models and really had a reason to remove them from newer OS X versions. So the 64-bit usage is crippled for at least those models that use the Intel GMA X3100.

  5. September 22nd, 2011 | 3:07 am

    […] […]

  6. danny
    November 3rd, 2011 | 11:24 am

    Yep, patch doesn’t work on MacBook4,1

  7. danny
    November 3rd, 2011 | 12:04 pm

    Here’s some information on x3100 brightness btw

  8. November 28th, 2011 | 12:35 pm

    Yep, Good Results..

  9. Dray
    December 19th, 2011 | 12:03 pm

    Hi all, I have a Macbook 2.1
    Model Name: MacBook
    Model identifier: MacBook2, a
    The name of the processor: Intel Core 2 Duo
    Processor Speed: 2.16 GHz
    Number of CPUs: 1
    Total Number Of Cores: 2
    Cache Level 2: 4 MB
    Memory: 4 GB
    Bus Speed: 667 MHz
    Version of Boot ROM: MB21.00A5.B07
    Revision SMC (system): 1.17f0

    and efi boot only 32-bit, i try to use this loader–or-64-bit-kernel-startup-mode-selector
    but it dosent work, can i do something to load my mac in 64 bit kernl mod?

  10. February 13th, 2012 | 11:27 pm

    Here is new boot.efi patch for OS X 10.7.3.

    Not tested though (I currently only have the new Air), but it should work with all models that need it.

  11. microzix
    February 20th, 2012 | 4:12 pm

    You are awesome. I got my osx lion run in 10.7.3 on macbook3,1. Thank you very much!! Can you tell me how can I do it myself? Or are you gonna release one for mountain lion?

    Btw the kexts for x3100 are not working for me. Restarted my mb and all I got is the booting screen (grey wallpaper, apple logo) with spinning wheel. And sometimes my mousepointer appears but dissappear some seconds later.

  12. cktse
    February 21st, 2012 | 4:39 am

    @swegen – thanks so much for your patch scripts. It worked perfectly on my 2009 Mini (macmini3,1) on OSX 10.6.8.

  13. cab_007
    February 27th, 2012 | 4:02 am

    I just tried swegen’s latest boot.efi patcher and can verify that it worked for my MB 4,1 early 2008 6GB ram. Sleep and display brightness not functional, but everything else seemed good (incl. built-in wifi). It did feel slightly quicker than in 32bit, but the fact of no sleep and brightness controls, I’ve reverted back. I sure hope they decide to not defunct the older 64bit capable models with 10.8 release coming out.

  14. tHeKiLLeR17
    June 14th, 2012 | 6:14 pm

    Please update your script for 10.7.4, I need it for my iMac 5,1.
    Thank you very much!

  15. Jeff Bloomfield
    May 31st, 2014 | 4:23 am

    @swegen’s boot.efi patch and his updated graphics drivers work perfectly on my MBP 3,1

  16. Machy
    March 10th, 2017 | 8:57 am

    boot64.efi Link is broken, Please help? Just read about this fix & need ANY workaround for MacBook 3,1 – It won’t allow fresh install from USB OR DVD so far.. Thanks in advance! I’ve built Hackintosh, but still learning Mac

  17. December 17th, 2017 | 2:06 pm

    I’d need a x64 patch for my MacBook 3,1 to boot in 64bit Kernel of Lion 10.7.5
    anyone can help?

  18. July 30th, 2018 | 7:03 pm

    […] not sure I understand this… but I did find this stack exchange question which pointed to this solution to hack your core 2 duo MacBook and enable 64 bit operating systems to be installed on […]

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