Installing rEFIt on the hidden EFI system partition

Install rEFIt on the system partition, instead of using Mac OS X system volume, allows one to manage rEFIt independently from Mac OS X. It is also possible to wipe out Mac OS X entirely while still being able to use rEFIt to boot other operating systems, like GNU/Linux, FreeBSD, Solaris, or even Windows.

To install rEFIt on the hidden EFI system partition, follow this simple steps which I gathered from a post at the personal blog of Lincoln Ramsay.

From a Terminal or command-line prompt, run the following commands:

$ sudo mkdir /efi

This will create the mount point for the EFI system partition

$ sudo mount -t msdos /dev/disk0s1 /efi

This command will mount the EFI system partition (usually hidden from Mac OS X) into /efi. The EFI system partition is basically a 200MB FAT32 partition which is, by default empty.

NOTE: Please, take into consideration that EFI system partition is usually the first partition on the built-in hard disk, which is usually /dev/disk0s1, although it could be different on your system.

open /efi

This will open the /efi folder in Finder.

Now, download rEFIt and copy the contents of the efi folder into /efi.

In the end, you should have the following subdirectories on your machine:

  • /efi/efi/refit
  • /efi/efi/tools

Now, we will bless the EFI system partition:

sudo bless --mount /efi --setBoot --file /efi/efi/refit/refit.efi --labelfile /efi/efi/refit/refit.vollabel

I think blessing marks the partition mounted on /efi as bootable, uses /efi/efi/refit/refit.efi as the boot loader, then changes some OpenFirmware variables to boot the machine from this partition.

17 Responses to “Installing rEFIt on the hidden EFI system partition”

  1. When I try this it fails to boot to rEFIt on the next power cycle. I am using a Mac Pro and did everything as you described. It simply defaults to the Mac OS. I checked the NVRAM variables and it clearly shows that it is set to boot from the correct partition. Any ideas?

    Bryan Shaw said this on October 11th, 2006 at 23:31

  2. Errr… I’m no Mac expert, but:

    Did you previously installed rEFIt on the Mac OS X boot volume? And so, did you uninstall it?
    Did you install Apple Boot Camp?
    Can you boot from a Linux LiveCD and check, using parted, the EFI partition is marked as bootable?
    Have you synced up the partition maps using rEFIT?

    Felipe Alfaro Solana said this on October 12th, 2006 at 08:03

  3. Thanks for the instructions. Easy to follow and very comprehensive.

    After doing it, it takes about 25 sec. from switching on the machine to displaying the refit-screen. before (when refit was installed on disk0s2) those were some 4 sec. or so.

    Have you experienced the same?

    Wolf Mc Ewen said this on February 13th, 2007 at 01:14

  4. No, I havent’ experience something like that.

    Did you sync the GPT/MBR partition tables? What partition is marked as active?

    Unfortunately, my Mac is gone for repairs so I cannot play, test or re-install rEFIt at the moment for sure I’ll once it’s back :-)

    Felipe Alfaro Solana said this on February 13th, 2007 at 01:32

  5. Thanks for for instructions.. I was stuck about bless command before I saw this guide. Very nice.

    But.. I have the same problem as Wolf Mc Ewen. I also have this problem if I wipe out the entire disk, make a MSDOS MBR partition table on it and install linux. It takes 20-25 seconds before grub kicks in. I have been crawling the net for days now for a guide on how to set this timer. In linux you have the efibootmgr which is supposed to be able to to this, but it won’t start because the efivars kernel module won’t load on an i386.

    This ha nothing to do with the syncing.. I think it’s an option with autoboot in EFI, but I can’t find a way to change it.

    By the way.. did a sync now while typing this and now the rEFIt Manager shows the EFI partition as an option to boot Legacy OS from HD.

    Now I am getting desprate..

    Morten Hersson said this on March 18th, 2007 at 02:59

  6. the refit 25s booting time is perhaps because you have a CD in the machine at the boot.

    vincent said this on May 1st, 2007 at 17:09

  7. Hi,

    I found the solution to my problem, btw.
    Zapping PRAM helped.

    Cheers

    Wolf Mc Ewen said this on May 26th, 2007 at 01:27

  8. [...] Installing rEFIt on the hidden EFI system partition at Felipe Alfaro Solana Install rEFIt on the system partition, instead of using Mac OS X system volume, allows one to manage rEFIt independently from Mac OS X. It is also possible to wipe out Mac OS X entirely while still being able to use rEFIt to boot other operating systems, (tags: osx hacks efi) [...]

    links for 2007-06-19 | /dev/random said this on June 20th, 2007 at 04:49

  9. Got a Intel book pro with no HDD from a closed compusa. If I follow your steps above, what else would I need to know. I’ll be installing either elive for mac book or fc 7, stability is not an huge issue. I run sidux on my p3 thinkpad. I right this from the elive cd. All the above seems more comprehensive then I have been reading in pieces elsewhere. Thanks jim

    Jim Sapp said this on August 5th, 2007 at 22:18

  10. “By the way.. did a sync now while typing this and now the rEFIt Manager shows the EFI partition as an option to boot Legacy OS from HD.”

    I’m getting this as well. Any idea on how to correct it?

    Thanks!

    Brian said this on August 30th, 2007 at 07:49

  11. [...] p.s. e lo faccio di cattiveria direttamente nella partizione nascosta… [...]

    bootcamp said this on October 4th, 2007 at 03:58

  12. Model Identifier: Macmini2,1
    Processor Name: Intel Core 2 Duo
    Processor Speed: 2 GHz
    Memory: 2 GB
    Bus Speed: 667 MHz
    Boot ROM Version: MM21.009A.B00
    SMC Version: 1.19f2
    $ diskutil list
    /dev/disk0
    #: TYPE NAME SIZE IDENTIFIER
    0: GUID_partition_scheme *111.8 Gi disk0
    1: EFI 200.0 Mi disk0s1
    2: Apple_HFS macaddict 55.6 Gi disk0s2
    3: Microsoft Basic Data 13.0 Gi disk0s3
    4: Microsoft Basic Data WINXP 13.0 Gi disk0s4
    5: Apple_HFS 14.9 Gi disk0s5
    6: Linux Swap 14.5 Gi disk0s6
    [15G Linux Swap is an historic accident ;-) ]
    When I follow your instructions it takes 30 seconds for rEFIt to be discovered.
    With /efi on the MacOS partition it is 3 seconds. Any idea why?
    peterk

    Peter Kerr said this on January 11th, 2008 at 01:25

  13. :-/

    The truth is that I haven’t played with rFEIt for a long time. I might take it for a spin later, but I’ve heard of other people having the same problems. Unfortunately, I don’t know much about EFI so I don’t really know what it takes so long.

    Felipe Alfaro Solana said this on February 5th, 2008 at 04:48

  14. QTparted in Linux see an error on used space. This is Unknown. Also report a message saying:

    “REFIT~1.MPKCONTENTSPACKAGESPARTIT~1.PKGCONTENTSRESOUR~1PARTIT~1.BOM is 0k, but it has 3 cluster (1k).”

    May It help?

    SiNiESTrO said this on February 5th, 2008 at 19:37

  15. [...] OS X we need to install rEFIt. Felipe Alfaro Solana has a nice guide on how to install rEFIt on the EFI partition, which is what we want. I have added the necessary [...]

    Anders Franz Terkelsen’s blog » Blog Archive » Ubuntu and Windows Vista dual boot on a MacBook said this on March 22nd, 2008 at 21:48

  16. [...] stage of the project: making rEFIt the default bootloader. At first I used the tutorial I found on Felipe Alfaro Solana’s blog for installing rEFIt to the hidden efi partition on the harddisk. Unfortunately, like some of the [...]

    Still working on it...MultiOS MacBook | Soul_Est's Vogue said this on July 9th, 2008 at 08:34

  17. I just tried this method and I also get the 25sec penalty.
    I alredy tried Zapping my PRAM and then reinstalling rEFIt onto the EFI partition, but it didnt help. Has anyone new information on this problem/bug?

    DodoFXP said this on July 23rd, 2008 at 03:56

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