Since I last dealt with writing an SD card image to update the BeagleBone software, some things have changed. So, here’s an updated guide to the process.

Download the Image

The latest images are available here: http://beagleboard.org/latest-images

The one I downloaded was named: Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.11.22.img.xz

Uncompress the Image

The latest BeagleBone images are not compressed in a format that tar or unzip can deal with. Fortunately there is a free application The Unarchiver that can. It’s available here: The Unrchiver.

Run this application on the .xz image file to get a (much larger) file that ends in .img. This is the file you’ll write to the SD card.

Unmount the SD Card

To write the image to the SD card, it first needs to be unmounted.

    $ diskutil unmount /volumes/YourCardNameHere

Find the Device Name

This step is critical.

Using the wrong device name can destroy the data on your computer’s hard drive, so be very very sure to get the device name correct in the following steps!

This can be found in a couple of ways. You can use the “Disk Utility” application, or the command line diskutil or df commands.

Diskutil

From the command line:

    $ diskutil list

df

    $ df

This may show you the partition, something like disk7s2. You want to entire SD card, not any partitions so drop the s2 part.

Write the Image

Then, write the image to your SD card. Note that the diskXXX should be the actual disk device assigned when the SD card is connected, and Angstrom-XXX should be the name of the actual card image you downloaded and extracted previously.

Again be sure to use the right device name for the SD card in this step!

Don’t be surprised if this takes a while – on my system it took about 37 minutes, and there are no “in progress” indications of any sort, so be patient! (note that this time is more a function of how big the image is – ~3.4G – and the speed of your micro-SD card then how fast your computer is)

    $  dd if=Angstrom-XXX.img of=/dev/diskXXX bs=4096

If you aren’t logged in as root, you may need to use sudo, in which case the command is:

    $  sudo dd if=Angstrom-XXX.img of=/dev/diskXXX bs=4096