To save your time to setup GCC for building this example, you can use InstantContiki 3.0 running on VMPlayer.
1. git clone --recursive https://github.com/openthread/openthread
2. cd openthread
3. run "./bootstrap"
4. do "make -f examples/Makefile-cc2538" and you will get arm-none-eabi-ot-cli.bin under /output/bin
5. Download arm-none-eabi-ot-cli.bin to two CC2538DK using Flash Programmer 2.
6. On one of CC2538DK, you can run Cli command "start" to create OpenThread network
> start start Done > state state leader Done
7. On another CC2538DK, you can run Cli command "start" to start OpenThread router when there is a OpenThread network existed.
> start start Done > state router Done
8. On leader node, you can use "scan" to see get the router node and use "ping" to ping the router.
9. On router node, you can use "scan" to see get the leader node and use "ping" to ping the leader.