08-26-2011 12:15 PM - edited 08-26-2011 03:28 PM
Just updated my M4 firmware on my 2011 mac mini (which has no Superdrive).
I spent ages trying to find out how to make a USB bootable drive that would allow me to run the update.
N.B. For step 6 remove the italicised text. The actual terminal command is being altered by a bad language filter!
Here is how I did it:
1. connect your USB drive
2. download rEFIt-syslinux . This will allow your USB drive to be recognised as a startup volume by the EFI, the mac's equivalent of a BIOS.
3. mount the dmg. This will mount two volumes called 'rEFIt' and 'SYSLINUX'
4. open Terminal and take a note of which volume is which with the command diskutil list
e.g. /dev/disk1 for the USB drive and /dev/disk2 for the dmg
5. unmount (NOT eject) both these volumes -
diskutil unmountDisk /dev/disk1
diskutil unmountDisk /dev/disk2
You should get output messages saying you were successful
6. Copy the dmg onto the USB drive
dd if=/dev/disk2 of=/dev/disk1 b<delete this>s=1m
You should get an output message detailing no. of records in and out and no. of bytes transferred
7. Eject both
diskutil eject /dev/disk1
diskutil eject /dev/disk2
8. unplug and plug back in USB drive and mount the SYSLINUX volume
9. mount the firmware ISO and go into the folder BOOT, then ISOLINUX
10. copy the contents into the SYSLINUX volume
11. delete the existing file syslinux.cfg and rename ISOLINUX.CFG to syslinux.cfg
12. reboot your mac and hold the option key to select a boot volume and select the eEFIt volume, then choose the "Boot legacy OS SYSLINUX' option
13. Update the firmware!
08-26-2011 01:16 PM
Thanks so much for these instructions! I have a MacBook Pro with a Crucial M4, but I've taken out my Superdrive and replaced it with and OWC Disk Doubler. For the last firmware update, I had to remove the SSD, put it into another computer, and run the update there.
Glad to see there's an easier way!
08-26-2011 03:23 PM
Thanks for the detailed guide.
08-27-2011 01:53 AM - edited 08-27-2011 01:54 AM
I have a Macbook Pro with no SuperDrive (it has been replaced by the SSD m4).
Unfortunately, it doesn't work for me. I got these error messages when I am booting from the USB key :
"Error : Not Found from LocateDevicePath" (19 times)
"Error : Load Error while (re)opening our installation volume"
08-27-2011 01:39 PM
This message comes for me, too, but only when I disconnect the SSD/system disc. When I do not disconnect it then the Mac boots into bootcamped Windows instead of booting the Linux/DOS image from the USB Stick (same happens when trying to boot from an eSATA CD drive, but not with USB CD drive).
The problem seems to be that the stupid Mac still tries to boot into bootcamped Windows even when its not accessible anymore.
08-27-2011 01:48 PM - edited 08-27-2011 02:06 PM
What does diskutil list say for your USB Drive?
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *160.0 GB disk1
1: DOS_FAT_32 SYSLINUX 8.2 MB disk1s1
2: Apple_HFS rEFIt 23.2 MB disk1s2