I have been trying to get GCC to work with the .Net Micro Framework Porting Kit (PK), but unlike the commercial compilers that are supported for the PK (MDK, etc.), there are five dozen different ways to build a GCC/ARM toolchain.
In .NET Micro Framework Porting Kit V3.0 with GCC Support?, Stefan Schmidt had suggested using Raisonance's free ARM toolchain, since a none EABI compiler is required. I had downloaded it, and tried it out, but I also asked the NETMF support team which toolchain they are using internally, since it will likely make any support inquiries easier, and save me a headache as well. Apparently, they are using the (also free) Sourcery G++ Lite toolchain from CodeSourcery. I opted to use the older Q3 2007 release (reference in the previous link), since the newer releases use GCC 4.3, whereas the porting kit was tested to work with 4.2.
Once I can get the NativeSample project up and running, I'll post a tutorial on how to properly configure Sourcery G++ Lite with the PK.