64 bit kernel macbook 5.1?

Discussion in 'MacBook' started by unixperience, Jul 9, 2011.

  1. unixperience macrumors regular

    Jul 21, 2010
    Hey guys, this is a pretty common topic. But I can only seem to find threads about the macbook 6.1 and 7.1, not the aluminum ones

    so, does anyone know how to boot the aluminum macbooks with the 64 bit efi? I know everyone will say there is no difference, but there is, well in my case, I need it for one program: Virtualbox.

    Virtual box on a 32 bit system will only allow me to alot 3.5 gigs of ram to a VM, and even then it crashes at 2.5G not even 3.5G (common problem after reading around). I want to alot 4 Gigs to windows, but virtualbox senses it's 32 bit and will only allow me to choose up to 3.5 gigs(not that that works) even though I have 8 gigs of ram. When you have the 64 bit kernel it allows you to allocate up to the full 8 gigs. I have 64 bit windows so the ram won't be an issue there, I just can't allocate that much.

    So I can go with a solution to the 64 bit efi, or if someone knows how to trick virtualbox into letting me choose more memory that would be great too. thanks :eek:
  2. atMac macrumors 6502

    Jun 20, 2011
    I had to hack my EFI to get it to boot into 64-bit
  3. gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
  4. unixperience thread starter macrumors regular

    Jul 21, 2010
    thanks for the replies guys

    gr8tfly- the 64 combo, and the plist thing only works for macbook pros, by default without any hacking, macbooks are not allowed to boot the 64 bit kernel.

    atmac d you have an aluminum macbook? did you modify the efi yourself? or did you download it somewhere?(if you did it yourself how did you open the efi? i'm perfectly comfortable edition the hex code.. i just don't know how to display the file in something i can understand) I tried downloading it somewhere but my computer wouldn't boot till i used the regular boot file again.
  5. hekokimushi macrumors regular


    Oct 27, 2008
    used to follow an online tutorial to edit the boot.efi in S/L/Core Services

    lost the reference. i think it was from nektas.org
    i have a working boot64.efi if on 10.6.7 on my MB5,1.

    happy to upload it to anyone in need of this.
  6. pineapple216 macrumors member


    Apr 12, 2010
    I've got a working 64-bit kernel on my MB 5.1 with 8GB RAM (10.6.8).
    You should look at


    The site discribes how to replace your boot.efi file with another one, and with that enable the 64bit kernel.

    Go to post #151.
    (You can find the link for the boot64.efi file you need in post #174)
    Good luck!
  7. unixperience thread starter macrumors regular

    Jul 21, 2010
    thanks for all your help guys, i got it to work, i can give 4 gigs to windows like I wanted, thanks thanks THANKS;)

    I do have one more question though, if I do the system update to 10.6.8, will that undo all the changes?? so it won't boot into 64 bit anymore?
  8. hekokimushi macrumors regular


    Oct 27, 2008
    i took the bullet and tried
    updated to 10.6.8 first on my USB back up drive. all went ok. TRIM enabler applied, restarted, then of course was back to 32bit. all went ok. so put it on the main SSD. rebooted!! WoWoo00wwWwW i only had 1.5 gear spin boot. that was amazing with 32bit Kenral. and i had TRIM going for 10.6.8.

    then reapplied the 64bit EFI... rebooted. 6 gearspins... (back to what it was before) so i guess... 64bit kernal does take 5 more gearspins to load. so be it.

    i now have an operating 10.6.8 at 64bit with TRIM on my MB5,1 :-D
    fingerscrossed for the dock, no visible problem as is at this second. :apple::apple::D:D:rolleyes:
  9. unixperience thread starter macrumors regular

    Jul 21, 2010
    wow that is great to hear hekokimushi, I will give it a try on my external as well. its so nice you can boot off externals and not risk your internal harddrive :rolleyes:
  10. hekokimushi macrumors regular


    Oct 27, 2008
    yes... good for trial and error testing purpose. just hold OPTION (ALT) before the apple ding at boot up. select USB drive to boot.
  11. swegen macrumors newbie

    Jul 20, 2011
    I put together easy-to-use boot.efi x64 patches for all models that do not support native booting into 64-bit kernel.

    Just run patch, enter admin password (required to modify a system file), reboot and you should boot into 64-bit kernel.
    Restore to original boot.efi also included.


    I have tested the patches with MacBook3,1 & MacBookAir3,2, but it should work with all models.
  12. hekokimushi macrumors regular


    Oct 27, 2008
    upgrade to Lion solves all 64bit problems. only u need to relearn how to use your MB from new:eek::eek::eek:
  13. unixperience thread starter macrumors regular

    Jul 21, 2010
    Thanks for all your help, and that batch file is pretty cool. I have a similar one.

    As a side note, I upgraded to 10.6.8 (dont know about the Lion update yet, I might try it on an external first) and the 64 bit works fine, just in case someone reads this later down the road, you know it worked for at least two people haha
  14. brdeveloper macrumors 68020


    Apr 21, 2010
    Looks like it worked to me. I have a late-2009 Unibody Macbook 2,26GHz (6,1). Now the OS takes a little longer to boot (in my Samsung 840 EVO SSD). Thank you! I'll report eventual crashes if they ever happen.

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