Software can be cross-compiled using Xilinx tools, or compiled natively on the RCE.
Cross Compilation
Purchase Xilinx software/license for access to the arm-xilinx-eabi gcc toolchain.
Native Compilation
Install compiler packages from /opt/RCE_SDK/tgt/linux/packages/extra
pacman -U gcc-5.2.0-2-armv7h.pkg.tar.xz binutils-2.25.1-2-armv7h.pkg.tar.xz libmpc-1.0.3-1-armv7h.pkg.tar.xz
Use native gcc toolchain