What is this?

This is Project Shodan, a project to research the fusion of novel hardware and software architectures to produce a low-power, ambient AI core. For more information, see our internal site at sites/cerebrahardware/shodan.

Developing in this Codebase

We've stored our code in Gerrit, and like the Android developers before us, we use repo to manage the projects in our Gerrit repositories.

To get started, first make sure you have a Git login for all our projects by going to googlesource.com/new-password and pasting the provided script into a terminal.

Now you need to pull down a copy of the repo tool from our public facing sites and add it to your path:

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

Make sure you've initialized git with your name and email address, and have configured it properly for fetching the sources:

git config --global user.name "Your Name"
git config --global user.email "you@example.com"

Once you‘ve done this, you’re actually ready to check out the sources. Make a new directory where you'd like it to live, and initialize repo with the current release branch.

repo init -u https://spacebeaker.googlesource.com/manifest
repo sync -j$(nproc)

Day-to-day Development Workflow

In general, working with repo is relatively simple:

  1. Create a working topic branch to make changes on with repo start ${TOPICNAME}
  2. Make your changes to the files. Add them with git add -A and commit with git commit.
  3. Upload your changes with repo upload --re ${REVIEWER} --cc ${CC_LIST}
  4. Go to the URL repo spits out to read and reply to comments.
  5. Eventually your reviewer will give you a +2 LGTM on your change. To submit, click the “SUBMIT” button on the change in the web interface.
  6. Run repo sync -j$(nproc) to update.
  7. Run repo prune to remove your topic branch.

For more information on how to use repo and git effectively, take a look at the official documentation.

How to sync my local copy with latest?

repo sync -j$(nproc)

Then if you have any outstanding branches, a repo rebase will help.

How to send code for review?

To upload a branch to gerrit for review, do this:

repo upload --re reviewer1,reviewer2 --cc email@host.com,email2@host2.com

Reviewers can be specified as usernames or full email addresses, likewise for --cc.

Repo will then output a URL for you to visit that allows you to make comments and abandon and merge the changes into the repository. To make changes during the review process, make your changes to the files, then:

git add -A                                    # To add the files you've changed
git commit --amend                            # To update the previous change
repo upload -t --re ${REVIEWER} --cc ${CC_LIST} # To upload the change to Gerrit for review

Repository Layout

Our layout is pretty simple:

hw/

Contains the all of the source code and RTL required to build the Shodan hardware, as well as simulate it in Verilator.

build/

Contains build scripts for the whole tree. This is effectively just an orchestration layer to make building the whole shebang easier. Each subtree may have its own build systems and have their own ways of building.

cicd/

Contains continuous integration scripts and tooling for Jenkins, our CI/CD tool.

docs/

Lots of extra documentation (we hope) about how the repo is laid out, how the build system works, code reviews, licensing, etc.

manifest/

The repo manifest used to glue all the git repositories together.

scripts/

Contains utility scripts to help automate a few things.

More Information