Zephyr microPlatform Workflows HOWTO¶

This page describes the workflows for developing and deploying embedded applications with the Zephyr microPlatform. It assumes that the Zephyr microPlatform has successfully been installed as described in Install Zephyr microPlatform.

Use Repo to Fetch Updates¶

The Zephyr microPlatform uses the Repo tool to manage its Git repositories. In Install Zephyr microPlatform, you used this tool to clone these Git repositories into a Zephyr microPlatform installation directory on a development computer. See Repo Primer for Zephyr microPlatform for more details.

After the installation, you’ll continue to use Repo to fetch upstream changes as follows.

Enter the .repo/manifests subdirectory of the Zephyr microPlatform (this is where the Repo manifest repository is installed on your system).
Use git to note the current Git commit SHA of the manifest repository. For example:
```
git --no-pager log -n1 --pretty='%H'
```
We’ll call the current SHA STARTING_MANIFEST_SHA.
Go back to the top level Zephyr microPlatform installation directory, and use Repo to sync updates:
```
repo sync
```
Warning

If you make any changes to any repositories managed by Repo, this will attempt to rebase your local branches, which can cause conflicts. Please see Managing Out of Tree Patches for more details.

You can use repo sync -n to fetch changes only, without rebasing, and then use Git to inspect the differences between your local and the upstream branches, merge or rebase appropriately, etc.

This is currently considered an advanced use case. If you are trying this during the beta period and you run into problems, please contact us.
After running repo sync, you can use the zmp helper script documented above to re-build and re-test your application, and make adjustments.

We recommend comparing your application with the updated version of the sample application you started from for relevant updates. This will let you adjust your application if needed to keep up with upstream.

If you run into problems, you can temporarily roll back to a previous Zephyr microPlatform release as follows:

$ cd .repo/manifests
$ git checkout STARTING_MANIFEST_SHA
$ cd ../..
$ repo sync

However, this defeats the purpose of receiving continuous updates from Open Source Foundries.

Managing Out of Tree Patches¶

While an upstream first approach is recommended for development, situations come up when out-of-tree patches are necessary for a microPlatform project such as Zephyr. Repo has built-in tooling to handle this workflow. The repo start command informs Repo that development will take place in a given branch name for a project. Once Repo is aware there are development branches for a project, repo sync will take care of rebasing the patch(es).

# work starts at latest microPlatform release
# A fix is required in Zephyr, the patch was submitted upstream, but is
# is still awaiting review. In the meantime, a branch can be used with:
$ repo start github-pr-XXX zephyr
$ cd zephyr
# apply the patch(es) to zephyr
$ git commit -a -m "out-of-tree patch waiting for zephyr merge #12"
...
# A new update comes in for the microPlatform
$ repo sync
...
# If no merge conflicts are detected, everything is done. Otherwise
# you will have to drop into the zephyr directory and use Git to
# resolve the merge conflict.