How to create an OSX86 USB installation drive on a Mac

(This is based on this OS X tips and tricks page on the osx86project.org wiki)

If you'd like to be able to install OS X - retail or one of the modified distros available, e.g. iAtkos, iDeneb, Kalyway (Google search), Leo4All, MsiWindOSX (Google search), etc - from a USB flash drive instead of having to use a DVD and DVD drive, the process is very simple as long as you have access to a Mac (this guide doesn't cover making a USB drive bootable using a PC).

Update 14/03/2009: for some strange reason, the USB key will not boot when the EFI bootloader is written from a Macbook Pro (or any Mac?), but works fine when OSx86Tools is run from a Hackintosh. Am looking into this and will post more when I find out...

Please read the disclaimer, below, before starting anything! Also, note that some older hardware - usually more than two years old - cannot support booting from a USB device. Please check your hardware before starting this.

Comments, questions, corrections, random abuse, etc? Send them to me here.

Contents

You will need

  • A Mac (this has been tested on 10.5 Leopard - YMMV on older versions)
  • A USB flash drive, at least 4GB (it needs to be at least the size of your installation image, and ideally a few hundred MB larger than that again)
  • An OS X installation image or a copy of the OS X installer DVD
  • A copy of OSX86 tools

How to...

Set up your USB drive

  1. On your Mac, plug your USB flash drive in
  2. Start Disk Utility
  3. The drive should be use MBR - see the information panel on the bottom of the Disk Utility window. It probably will be, but if it isn't you should repartition it following the steps below
  4. You might want to partition your USB drive while you're here, to get the most out of the space:
    1. Click "partition", then click "options" underneath the partition diagram and make sure it's using "MBR"
    2. The first partition should be OS X Extended (journaled) - this will contain your OS X installer image, so it should be around the size of your OS X install image plus roughly 500MB (as long as it's larger than the image, you'll be fine)
    3. If you create other partitions, it's up to you how you format them, but formatting as Windows (FAT) will let you load the drive with useful OS X and Windows utilities to carry around with you, should you need them
    4. Finally, follow the on-screen instructions to partition and format the drive

Copy the OS X installer image onto the flash drive

  1. Select your new OS X Extended (journaled) partition - not the flash drive itself - from the list of drives on the left of the screen and click the "restore" tab
  2. Mount your OS X installation image, or insert the DVD. The media should show up in the drives list on the left of disk utility
  3. Drag the installer image (again, not the drive itself, but the install image under/after the drive in the devices listing) on to the "source" field (if you can't drag it in, you're probably dragging the drive/disk image. Try dragging the next item down the list instead)
  4. Drag the newly-created partition on your flash drive into the "destination" field
  5. Finally, click the "restore" button. This process never presented me with any errors, so if you do have any problems here, Google is your friend

Make the USB flash drive bootable

  1. Install OSX86 tools on your Mac Hackintosh (see note at the top of the page - EFI seems to need to be burned from a Hackintosh. Odd...)
  2. Run the OSX86 tools app (it'll be in your Applications folder)
  3. Click "Install EFI"
  4. Select your USB flash drive's OS X partition. Important: if you choose the wrong drive here, you could cause yourself a whole world of pain-in-the-arseness. Be careful ;o)
  5. I chose to install the "PC_EFI v8" bootloader. Feel free to give all three a go to see how they vary.
  6. Follow the on-screen prompts to finish installing the bootloader.
  7. And finally, insert the key into your PC and try booting from it!

Disclaimer

The instructions above can seriously damage your computer. Don't carry out these steps if you don't know or are not sure what you're doing. If in doubt, seek advice. If you're still in doubt after that, better to not do it than to risk breaking your computer, an expensive flash drive, etc.

Also, some of the instructions above may reference software or practises which may invalidate your warranty or infringe copyright. Please take care to ensure you are acting on the right side of the law where you are.

Finally, all trademarks and copyrights are owned by their respective owners. No endorsements of any kind, implicit or explicit, are given for software and, likewise, I'm not approved or authorised to do this by anyone. Please bear in mind that this information is provided for people curious to get their computers doing unusual or unheard-of things.

Or, to put it another way, don't sue me if it all goes wrong. Please :o)