I want to start with the Crucial SSD Firmware Update and copy the ISO to a bootable Mac USB stick, using a minimal set of tools. I hope that means using only built-in Mac software, such as Disk Utility and Terminal for commands. If necessary, I will reluctantly use a commercial tool. (As of this writing, the latest is Crucial_m4_040H-04-00.zip.)

I've have waded through a muck of articles about how to copy an ISO to a bootable USB stick, but I have not found a solution that works and that I'm comfortable trying.

  • Patiently waiting for an answer as well since I have a Crucial m4 and just discovered that the Superdrive in my MBP is no longer functioning :(
    – EmmEff
    Commented Feb 27, 2013 at 21:50
  • Macs are quite challenging to create bootable USB sticks for (unless of course you're booting an OS X variant, in which case it's quite simple). My recommendation unfortunately is to go to an Apple Store and ask a Specialist if you can borrow a USB SuperDrive for a few moments with them. You can then burn a blank DVD (that you bring with you) and boot this way. Wish I had a better suggestion.
    – bispymusic
    Commented Mar 2, 2013 at 20:16
  • Can you try this youtube.com/watch?v=mndO508xq08 and see if it works for you?
    – Stephen
    Commented Jun 20, 2013 at 16:46
  • @David James Please let me know if that link works for you?
    – Stephen
    Commented Jun 20, 2013 at 20:32
  • @Stephen Why not post your answer as an answer?
    – David J.
    Commented Jun 21, 2013 at 3:51

6 Answers 6


I downloaded the Crucial_m4_040H-04-00.zip and followed this tutorial and everything seemed to work for me. I hope this helps.

  • And were you able to boot from the USB drive after that?
    – jmk
    Commented Jul 27, 2013 at 18:24
  • Yes I was able to boot from the USB drive.
    – Stephen
    Commented Jul 29, 2013 at 14:43

This does not answer the question directly but it applies to a very similar problem. I faced the same issue recently when trying to update the Firmware of my Samsung EVO 840. The people at Samsung who wrote the instructions for OS X are either trolls or have no knowledge of the subject.

I also tried countless ways of making a bootable USB with the firmware (also with rEFInd), but eventually it became clear that the only viable way was to burn it to a CD or DVD and boot from it. In case you have an optical drive (external one does not work), you could try the same. Steps are outlined here.

Disclaimer: Try this at your own risk.


Not sure if you have resolved the issue, but I'll explain how I did it here in case it's useful for other people.

I was trying to upgrade firmware for a Crucial m4 256G SSD on a mid-2012 27" iMac. The iMac does have its original internal HD, which turns to be crucial for solving the problem.

The main problem was that iMac refused to boot from an external USB drive, even using rEFInd.

The following steps worked for me:

  1. Install rEFInd
  2. Use UNetBootIn to create a bootable USB drive from Crucial's firmware updating ISO. This USB drive contains both syslinux and Crucial's firmware (which I think is in boot2880.img)
  3. Erase the internal HD with Master Boot Record and FAT32 file system
  4. Use dd to copy the bootable USB drive to the internal HD, e.g. dd if=/dev/rdisk2s1 of=/dev/rdisk1s1 bs=4m. Note that this does a byte-to-byte copy, so using a small USB drive if you can to save time.
  5. Remove USB drive and reboot. rEFInd should be able to find a Linux OS on the internal HD. Boot from that Linux OS, then choose the second "default" option from the boot loader menu. The upgrader should run then.

Hope this helps!


I created a USB drive from Windows with Rufus, MBR layout (BIOS or UEFI-CSM, FAT32) and ISO image mode. Booted up the MBP with ALT and two USB options showed up: Windows, EFI.

As EFI didn't work I tried Windows and voilá - Micron Storage Executive booted up and successfully flashed the MX300 to M0CR070.


Try downloading a bootloader called rEFIt to boot the USB. Delete the EFI folder in the Hard Drive Root folder to remove it.


  • Could you enhance your answer by adding a link for rEFIt and more detailed instructions on how to proceed after the download?
    – nohillside
    Commented Jul 27, 2013 at 14:59

Is not strictly using just mac tools, but if you have Windows running on Virtual Box or access to a Windows PC, you can use Universal USB Installer to create the USB stick. It worked great for my Macbook Pro.

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