Build your own OpenJDK
The below links cover build OpenJDK natively or in the cloud enviromnment for Linux/Unix environments. Before going to the links below, check out these Handy bash scripts.
Go to the Adopt OpenJDK - Build OpenJDK page to find out more about building on other platforms.
You can also follow these instructions to build it on the cloud environment as long as you provision the appropriate environments and follow the instructions from the links above.