Please check this.
Sync with git
•You have installed Git. Install Git with the following command:
sudo apt-get install git-core
•Your system has the default Git port 9418 open for outbound connections.
To sync the kernel sources
•Get the kernel source by running the source_sync.sh script:
sudo ./source_sync.sh -k
When prompted enter a ‘tag’ name, as provided in the release notes.
You can sync to any Linux tag you like. However, the tag provided in the release notes syncs the sources to the same source revision the release binary was built from. To see a list of the available release tags, use:
$ git tag -l tegra-l4t*