As XC said in a comment, as of 2.0, the CTS is freely available.
For it to be runnable, you have to build the tests.
In your top level android directory, do all the normal build set-up steps and then
make cts
Then in the out/host/linux-x86/cts/android-cts/tools
sub directory, you will find the startcts
bash script. I expect the location might depend on what platform you are building on. Modify it to point out your SDK and then run the script. It is relatively self explanatory.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…