Even though OS X default IDE is XCode (for C, Objective C, Java) and the fact that we can use XCode for programming an ARM7 MCU, using Eclipse is great because you can share your project with Linux (and Windows) users, use Mercurial, CVS or SVN as version control, among others interesting things that you can do with Eclipse.
Before going into the IDE, we must install a GCC toolchain that let us compile and generate ARM7 compatible binary files. And of course, there is a port of GCC for ARM7 architecture for Mac. Between all the toolchains available I like Yagarto (www.yagarto.de), it’s available for Windows and Mac, and in SourceForge you can find a DMG for OS X (http://sourceforge.net/projects/yagarto/files/). The lastest release of Yagarto for Mac includes GCC 4.4.2 and Binutils 2.20, while the Windows release includes GCC 4.5.0 and the same version of Binutils. Despite of this “small” difference, it works pretty well. So, download this release, and following the Readme file. Basically you need to unpack “yagarto-4.4.2” and include two paths into the System Path (everything is very well explained in the Readme file).
Once you have installed Yagarto, open a Terminal and type “arm-elg-gcc -v”. You should see something like:
If this is what you see, then everything goes right. If not, check Yagarto documentation, it’s very clear.
As I have mentioned before, Eclipse will be the base IDE, not only because of compatibility, but also because there is a great plugin called GNUARM that help us dealing with configurations and Makefile. Download Eclipse for C/C++ Developers (http://www.eclipse.org/downloads/) and copy into your home folder. Launch it and select a workspace. Once there, go to “Help” -> “Install New Software” and configure a plugin site with the following configuration:

Disable “Group items by category” as the plugin doesn’t have a category and appears hidden. Install the plugin and restart Eclipse.
Now if you create a C or C++ project, you will see a similar window that let you create an empty project for ARM. Simply type a name for the project, select “ARM Cross Target Application” -> “Empty project” and click “Finish”.
In the project’s property you will see all the parameters related with compiling, linking, and generating the binary file.
