For those interested, I was able to build the firmware from Xcode 6.1 on OS X 10.10 fairly easily. As long as you have followed all of the above instructions and therefore have CrossPack AVR and GNU Tools for ARM installed, all that's left to do is:…
@Mesmerised thank you! Even though I have show all hidden files enabled on my mac and can see .DS_Store and others, the ._AppleDouble files do not show up. Popped the card into a Windows PC and saw them right away. I downloaded Tinkertool, but I'm n…