Updated Getting Started (markdown)

Getting-Started.md

@@ -140,7 +140,7 @@ At that point, you will have a functioning micropython executable, which may be
 
 ## Microcontrollers (Bare-Metal, without an OS)
 ### ARM-based microcontrollers
-On a Ubuntu 12.04LTS this worked 
+On a Ubuntu 12.04LTS this worked. First remove the arm-none-eabi that comes with Ubuntu 12.04LTS and install the gcc-arm-embedded version.
 
 > sudo apt-get remove binutils-arm-none-eabi gcc-arm-none-eabi