Once you have determined the build host can build an AGL image, you need to download the AGL source files. The AGL source files, which includes the Yocto Project layers, are maintained on the AGL Gerrit server. For information on how to create accounts for Gerrit, see the Getting Started with AGL wiki page.

NOTE: Further information about Download and Build AGL Source Code available at AGL wiki.

The remainder of this section provides steps on how to download the AGL source files:

1. Define Your Top-Level Directory: You can define an environment variable as your top-level AGL workspace folder. Following is an example that defines the $HOME/workspace_agl folder using an environment variable named "AGL_TOP":

   $ export AGL_TOP=$HOME/AGL
   $ echo 'export AGL_TOP=$HOME/AGL' >> $HOME/.bashrc
   $ mkdir -p $AGL_TOP
   

2. Download the repo Tool and Set Permissions: AGL Uses the repo tool for managing repositories. Use the following commands to download the tool and then set its permissions to allow for execution:

   $ mkdir -p $HOME/bin
   $ export PATH=$HOME/bin:$PATH
   $ echo 'export PATH=$HOME/bin:$PATH' >> $HOME/.bashrc
   $ curl https://storage.googleapis.com/git-repo-downloads/repo > $HOME/bin/repo
   $ chmod a+x $HOME/bin/repo
   

NOTE: See the "Repo Command Reference" for more information on the repo tool.

1. Download the AGL Source Files: Depending on your development goals, you can either download the latest stable AGL release branch, or the "cutting-edge" (i.e. "master" branch) files.

2. Stable Release: Using the latest stable release gives you a solid snapshot of the latest know release. The release is static, tested, and known to work. To download the latest stable release branch, use the following commands:

   Note: In this below command please change the branch name to the latest stable release branch. For example, for Nifty Needlefish branch use the last name i.e. "needlefish" as branch.

   $ cd $AGL_TOP
   $ mkdir <<branch name>>
   $ cd <<branch name>>
   $ repo init -b <<branch name>> -u https://gerrit.automotivelinux.org/gerrit/AGL/AGL-repo
   $ repo sync
   

3. Cutting-Edge Files: Using the "cutting-edge" AGL files gives you a snapshot of the "master" branch. The resulting local repository you download is dynamic and changes frequently depending on community contributions. The advantage of using "cutting-edge" AGL files is that you have the absolute latest features, which are often under development, for AGL.

   To download the "cutting-edge" AGL files, use the following commands:

   $ cd $AGL_TOP
   $ mkdir master
   $ cd master
   $ repo init -u https://gerrit.automotivelinux.org/gerrit/AGL/AGL-repo
   $ repo sync
   

Once you sync the repository, you have the AGL files in the form of "layers" (e.g. meta-* folders). You also have the poky repository in your AGL workspace.

Listing out the resulting directory structure appears as follows:

$ tree -L 1
 .
 ├── bsp
 ├── external
 ├── meta-agl
 ├── meta-agl-cluster-demo
 ├── meta-agl-demo
 ├── meta-agl-devel
 ├── meta-agl-extra
 └── meta-agl-telematics-demo