Assuming that the SDK is installed in sdk_root directory, issue the following command

 source  <sdk_root>/environment-setup-<chipset>-rdk-linux-gnueabi

Example:

 source RNE-3.0/environment-setup-cortexa7t2hf-vfp-vfpv4-neon-rdk-linux-gnueabi

Here RNE-3.0 is sdk_root directory

Now all the cross compiler tools are available for development. Four native sample applications are provided as part of build. To build the samples, go to the samples directory and execute the following command

 ./build_samples.sh

After the samples are built they are contained in a partnerapps directory for copying to the provided device.