What I want:

  • Linux on an Intel iMac (Core Duo).

What I have:

  • An empty PC (17" Intel iMac) with broken CD drive. It's model A1173.
  • This PC with Ubuntu 12.04 and an old Windows Vista partition.
  • a USB flash drive and an Ubuntu ISO.


  • No CD means the only boot drive I could use is USB.
  • There is no BIOS on Macs, so I can't set boot settings or even see if it detects my USB drive. When I start the machine and press Option, the first and only thing I see is an old corrupted Windows XP partition and not a single option or additional information.
  • So assuming blindly that the Mac hardware/firmware works normally, I don't have any Mac OS to use any of the tools that I found on different tutorials for building a bootable drive for Macs.
  • I can't find much software on Linux/Windows to substitute to those tools, for example among others converting an .iso file (Win/Linux) to .img (Mac I guess). Which makes me think that the scenario where someone like me has Mac hardware but no Mac OS is extremely rare.
  • So other than finding someone that has a Mac I have no solution. So I ask, what would you do? The only thing is it should not involve any money (I know Mac software is rarely free) which also excludes getting any Mac OS unless I can use a free macos.img for VM or restore the original Mac for free.
  • 2
    iMac G5s are PowerPC, not Intel, and there is a BIOS per se: it's called Open Firmware and you can do way, way more stuff in there than in any BIOS.
    – Cajunluke
    Jun 12, 2012 at 16:41
  • Also, .iso and .img are basically the same, and Macs are quite happy to handle .iso images.
    – Cajunluke
    Jun 12, 2012 at 16:42
  • Question on Super User: superuser.com/questions/435866/imac-g5-with-no-os-nor-cd-drive Jun 14, 2012 at 0:10
  • @CajunLuke 1) I meant a usable BIOS, if you KNOW there is one, please tell me how to use it. 2) My g5 IS an intel PC, you shouldn't have edited that out. 3) .iso images may be handled but they still need to be converted to .img even though they're so similar.
    – sinekonata
    Jun 14, 2012 at 23:58
  • @sinekonata If it is a G5, it is by definition not Intel, as G5s are PowerPC chips. If it is an Intel iMac, then it's not a G5 iMac, it's an Intel iMac.
    – Cajunluke
    Jun 15, 2012 at 0:00

4 Answers 4


Looks like you have all you will need already, you were just missing the following bits of information.

  1. You should checkout a Ubuntu instructions for Intel Macs, so no need to worry about a BIOS your running EFI. Ubuntu for Intel Macs and additionally the Ubuntu Intel Mac CommunityHelpPages looks to be loaded with lots of resources that you might find helpful.

  2. Since your iMac is an intel one, you can use a standard Ubuntu ISO built for any x86 PC. However since your iMac is a Core Duo it will need a 32bit Ubuntu as noted on Ubuntu's Mac Community documentation.

... If you have a Core2 Duo Mac (as oppossed to the Core Duo), it is capable of using the AMD64 (64bit) CD otherwise you have to use the standard version...

The standard version meaning a 32bit version.

  1. Pick and download a 32bit version of Ubuntu , the Mac documentation pages say going with the latest version should be a good move, yet pick which one works best on your iMac, this may require trial and error.

  2. Follow the standard How to create a bootable USB stick on Ubuntu using the Ubuntu ISO you downloaded above.

  3. Boot the iMac with the USB stick inserted, if the iMac does not boot into the Ubuntu installer you may need to reboot and hold down the "option" key, and then selcted the USB stick to continue booting into the Ubuntu installer.

  • CajunLuke edited my PC specs out saying it's an intel mac so sorry about that but this answer won't fit. I don't worry about BIOS I worry about not being able to follow this tutorial since my lack of macos. And thanks for the 2nd link it'll be useful.
    – sinekonata
    Jun 15, 2012 at 0:07
  • @CajunLuke why don't you believe me? I have the serial number and you don't, the model # I gave should be enough proof...
    – sinekonata
    Jun 15, 2012 at 0:16
  • 1
    @sinekonata I missed the model number the first time, and you mentioned G5 more than Intel, so I assumed you got it right more than you did wrong. I've edited the question to say Intel everywhere and not G5. That's why everyone (including me, MrDaniel, and everyone over at Super User) assumed PowerPC: it looked like the one reference to Intel was a mistake.
    – Cajunluke
    Jun 15, 2012 at 0:18
  • There is a major error in this answer! The USB creation which you link only works on Ubuntu and will not EFI boot on a Mac. However, the instructions for OSX are not working on many Macs either.
    – gentmatt
    Jun 15, 2012 at 15:31
  • @sinekonata Please report what solution works for you. I've attempted several installations as well, but managed only an installation via USB using BIOS Emulation (no EFI boot). I've used UNetbootin and had to manually create a MBR partition on the flash drive.
    – gentmatt
    Jun 15, 2012 at 15:35

If you have a recovery partition still you could reinstall the OS with no cd by Holding both the Command and R keys on the keyboard once rebooted when you hear the chime noise.

once OS X is back installed follow the guide below in the link.


This is the correct way to make a Linux installer USB for use on Apple hardware.

This method to create installer will REQUIRE access to a working Macintosh with an OS installed and working.

download the iso from the following location:

http://www.ubuntu.com/download/desktop (PLEASE SELECT 32bit iso)

once you create your installer/live USB reboot your computer

hold option at the chime and select the usb.

  • Your description is rather confusing and probably not applicable to all Intel Macs. Also it's unclear how this relates to the problem described in the question.
    – nohillside
    Oct 20, 2015 at 8:47
  • I am not sure I understand your response. installing Linux on an Intel apple could not be easier. I think the question is little vague. are we dual booting here? are we running linux as the main and only OS? My answer does work on all Intel macs. (resolving graphics issues are usually the second step of the install) followed by just getting other proprietary hardware to run correctly. (some macs require additional programing to turn on fans/sensors... ECT)
    – jen nemo
    Oct 20, 2015 at 9:34
  • The question talks about how to get a bootable Linux onto Mac hardware. Resolving any post-boot issues would be another question (and off-topic on AD). As for missing details: "You will need the 32bit ISO" -> which one, where from? Do I want to run 32bit Linux on a 64bit CPU? What do I do with it once it's downloaded, how do I make a bootable stick? Does pressing Option automatically boot from the stick? How do I use `nomodeset?
    – nohillside
    Oct 20, 2015 at 10:06
  • ok I understand. I will remove the tips that he will need down the road. sorry and I will update with a link to the correct ISO.
    – jen nemo
    Oct 20, 2015 at 12:07

I think what the issue is here is the EFI intel booting.. first off, I understand the Box in question.. I have and early intel iMac that also has the intel core Duo (two cores but not much shared between the two. You essentially have a machine with two 32bit processors. that live to serve separately. Without special features of the "soft bios", that is, no Bios Chip on the motherboard the iMac will only boot with certain linux loaders that handle EFI booting properly. I am happily using super pup linux. I have tried booting with 20 differing linux packages and 17 of them have no clue what CDrom "type" I'm using and refuse to boot at all. Cool! soft BIOS..stupid BIOS. Since the original issue was, no internal CDROM, an external works just fine. I know, I just piked another up at a Good.. second hand store for $3. It boots my iMac at holding the option key. If you are looking for pure 64 bit computing from the core duo.. probably not gonna happen.. beside the memory capacity of the machine is limited.


This answer actually pertains to a this question and the closed question by mandesi c. Kaumba, which is titled Booting Linux on an 2006 iMac. The body of this question is given below.

I have removed a hard drive from my 2006 iMac and installed Ubuntu on it from another computer. However, after putting it back in the iMac, it is not able to boot. I am getting a question mark instead. Can anyone provide assistance?

The current 20.04 LTS release of Ubuntu has the following in the list of system requirements:

  • A 64 bit processor
  • At least a 2 GHz processor speed
  • 4 GiB of RAM (system memory)

None of the 2006 iMac models meet all of these requirements. While some models can accept 4 GiB of RAM, not all of this RAM can be accessed. The following excerpt was taken from everymac.com.

The net result is that at least 3 GB of RAM should be fully accessible, while when 4 GB of RAM installed, ~700 MB of of the RAM is overlapping critical system functions, making it non-addressable by the system.
Ultimately, 4 GB of RAM may be installed, but not all RAM in excess of 3 GB can be used due to the possibility of memory "overlap".

If your 2006 iMac has a 64 bit processor, then you might be able to install the current release of Xubuntu, which currently requires less RAM. However, all 2006 iMacs have a 32 bit EFI, so 64 bit operating systems can not be EFI booted from these Macs. This is the most likely cause of the problem described in mandesi c. Kaumba's question. However, for 2006 iMacs with 64 bit processors, there exists the possibility to BIOS boot 64 bit operating systems. However, below are some issues which need to be noted.

  • Many Linux installation DVDs (burned from Linux installation IS0s) contain more than one way to boot. For example, the DVD can be either EFI or BIOS boot. Many (if not all) 2006 iMacs can not boot from these types of DVDs.
  • Many (if not all) 2006 iMacs needed a firmware upgrade before being able to BIOS boot. To preform this upgrade, OS X needs to be installed on the Mac. Information on getting a Snow Leopard ISO file and creating an installer can be found here.
  • Some versions of Linux require the USB installer to be BIOS booted in order to install a BIOS booting operating system. The firmware for all 2006 iMacs can not BIOS boot from USB devices. However, the 32 bit Debian Linux USB installer can be 32 bit EFI booted and can install a BIOS booting Debian Linux. You can then use the Grub included with this installation to BIOS boot a 64 bit Linux installer (such as Xubuntu) and overwrite the 32 bit Debian with a 64 bit BIOS booting Linux. The procedure would be similar to what is post in this answer.

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