West Manifests

This page contains detailed information about west’s multiple repository model, manifest files, and the west manifest command. For API documentation on the west.manifest module, see West APIs. For a more general introduction and command overview, see Multiple Repository Management.

Multiple Repository Model

West’s view of the repositories in a west workspace, and their history, looks like the following figure (though some parts of this example are specific to upstream Zephyr’s use of west):

West multi-repo history

West multi-repo history

The history of the manifest repository is the line of Git commits which is “floating” on top of the gray plane. Parent commits point to child commits using solid arrows. The plane below contains the Git commit history of the repositories in the workspace, with each project repository boxed in by a rectangle. Parent/child commit relationships in each repository are also shown with solid arrows.

The commits in the manifest repository (again, for upstream Zephyr this is the zephyr repository itself) each have a manifest file. The manifest file in each commit specifies the corresponding commits which it expects in each of the project repositories. This relationship is shown using dotted line arrows in the diagram. Each dotted line arrow points from a commit in the manifest repository to a corresponding commit in a project repository.

Notice the following important details:

  • Projects can be added (like P1 between manifest repository commits D and E) and removed (P2 between the same manifest repository commits)

  • Project and manifest repository histories don’t have to move forwards or backwards together:

    • P2 stays the same from A → B, as do P1 and P3 from F → G.

    • P3 moves forward from A → B.

    • P3 moves backward from C → D.

    One use for moving backward in project history is to “revert” a regression by going back to a revision before it was introduced.

  • Project repository commits can be “skipped”: P3 moves forward multiple commits in its history from B → C.

  • In the above diagram, no project repository has two revisions “at the same time”: every manifest file refers to exactly one commit in the projects it cares about. This can be relaxed by using a branch name as a manifest revision, at the cost of being able to bisect manifest repository history.

Manifest Files

A west manifest is a YAML file named west.yml. Manifests have a top-level manifest section with some subsections, like this:

manifest:
  defaults:
    # default project attributes (optional)
  remotes:
    # short names for project URLs (optional)
  projects:
    # a list of projects managed by west (mandatory)
  self:
    # configuration related to the manifest repository itself,
    # i.e. the repository containing west.yml (optional)
  version: <schema-version> # optional

In YAML terms, the manifest file contains a mapping, with a manifest key. Any other keys and their contents are ignored (west v0.5 also required a west key, but this is ignored starting with v0.6).

There are four subsections: defaults, remotes, projects, and self. In YAML terms, the value of the manifest key is also a mapping, with these “subsections” as keys. Only projects is mandatory: this is the list of repositories managed by west and their metadata.

We’ll cover the remotes and projects subsections in detail first.

The remotes subsection contains a sequence which specifies the base URLs where projects can be fetched from. Each sequence element has a name and a “URL base”. These are used to form the complete fetch URL for each project. For example:

manifest:
  # ...
  remotes:
    - name: remote1
      url-base: https://git.example.com/base1
    - name: remote2
      url-base: https://git.example.com/base2

Above, two remotes are given, with names remote1 and remote2. Their URL bases are respectively https://git.example.com/base1 and https://git.example.com/base2. You can use SSH URL bases as well; for example, you might use git@example.com:base1 if remote1 supported Git over SSH as well. Anything acceptable to Git will work.

The projects subsection contains a sequence describing the project repositories in the west workspace. Every project has a unique name. You can specify what Git remote URLs to use when cloning and fetching the projects, what revisions to track, and where the project should be stored on the local file system.

Here is an example. We’ll assume the remotes given above.

manifest:
  # [... same remotes as above...]
  projects:
    - name: proj1
      remote: remote1
      path: extra/project-1
    - name: proj2
      repo-path: my-path
      remote: remote2
      revision: v1.3
    - name: proj3
      url: https://github.com/user/project-three
      revision: abcde413a111

In this manifest:

  • proj1 has remote remote1, so its Git fetch URL is https://git.example.com/base1/proj1. The remote url-base is appended with a / and the project name to form the URL.

    Locally, this project will be cloned at path extra/project-1 relative to the west workspace’s root directory, since it has an explicit path attribute with this value.

    Since the project has no revision specified, master is used by default. The current tip of this branch will be fetched and checked out as a detached HEAD when west next updates this project.

  • proj2 has a remote and a repo-path, so its fetch URL is https://git.example.com/base2/my-path. The repo-path attribute, if present, overrides the default name when forming the fetch URL.

    Since the project has no path attribute, its name is used by default. It will be cloned into a directory named proj2. The commit pointed to by the v1.3 tag will be checked out when west updates the project.

  • proj3 has an explicit url, so it will be fetched from https://github.com/user/project-three.

    Its local path defaults to its name, proj3. Commit abcde413a111 will be checked out when it is next updated.

The list of project keys and their usage follows. Sometimes we’ll refer to the defaults subsection; it will be described next.

  • name: Mandatory. the name of the project. The name cannot be one of the reserved values “west” or “manifest”. The name must be unique in the manifest file.

  • remote or url: Mandatory (one of the two, but not both).

    If the project has a remote, that remote’s url-base will be combined with the project’s name (or repo-path, if it has one) to form the fetch URL instead.

    If the project has a url, that’s the complete fetch URL for the remote Git repository.

    If the project has neither, the defaults section must specify a remote, which will be used as the the project’s remote. Otherwise, the manifest is invalid.

  • repo-path: Optional. If given, this is concatenated on to the remote’s url-base instead of the project’s name to form its fetch URL. Projects may not have both url and repo-path attributes.

  • revision: Optional. The Git revision that west update should check out. This will be checked out as a detached HEAD by default, to avoid conflicting with local branch names. If not given, the revision value from the defaults subsection will be used if present.

    A project revision can be a branch, tag, or SHA. The default revision is master if not otherwise specified.

  • path: Optional. Relative path specifying where to clone the repository locally, relative to the top directory in the west workspace. If missing, the project’s name is used as a directory name.

  • clone-depth: Optional. If given, a positive integer which creates a shallow history in the cloned repository limited to the given number of commits. This can only be used if the revision is a branch or tag.

  • west-commands: Optional. If given, a relative path to a YAML file within the project which describes additional west commands provided by that project. This file is named west-commands.yml by convention. See Extensions for details.

  • import: Optional. If true, imports projects from manifest files in the given repository into the current manifest. See Manifest Imports for more details.

The defaults subsection can provide default values for project attributes. In particular, the default remote name and revision can be specified here. Another way to write the same manifest we have been describing so far using defaults is:

manifest:
  defaults:
    remote: remote1
    revision: v1.3

  remotes:
    - name: remote1
      url-base: https://git.example.com/base1
    - name: remote2
      url-base: https://git.example.com/base2

  projects:
    - name: proj1
      path: extra/project-1
      revision: master
    - name: proj2
      repo-path: my-path
      remote: remote2
    - name: proj3
      url: https://github.com/user/project-three
      revision: abcde413a111

The self subsection can be used to control the behavior of the manifest repository itself. Its value is a map with the following keys:

  • path: Optional. The path to clone the manifest repository into, relative to the west workspace’s root directory. If not given, the basename of the path component in the manifest repository URL will be used by default. For example, if the URL is https://git.example.com/project-repo, the manifest repository would be cloned to the directory project-repo.

  • west-commands: Optional. This is analogous to the same key in a project sequence element.

  • import: Optional. This is also analogous to the projects key, but allows importing projects from other files in the manifest repository. See Manifest Imports.

As an example, let’s consider this snippet from the zephyr repository’s west.yml:

manifest:
  # ...
  self:
    path: zephyr
    west-commands: scripts/west-commands.yml

This ensures that the zephyr repository is cloned into path zephyr, though as explained above that would have happened anyway if cloning from the default manifest URL, https://github.com/zephyrproject-rtos/zephyr. Since the zephyr repository does contain extension commands, its self entry declares the location of the corresponding west-commands.yml relative to the repository root.

The version subsection can be used to mark the lowest version of the manifest file schema that can parse this file’s data:

manifest:
  version: 0.7
  # marks that this manifest uses features available in west 0.7 and
  # up, like manifest imports

The pykwalify schema manifest-schema.yml in the west source code repository is used to validate the manifest section. The current manifest version is 0.7, which corresponds to west version 0.7. This is the only value this field can currently take.

If a later version of west, say version 21.0, includes changes to the manifest schema that cannot be parsed by west 0.7, then setting version: 21.0 will cause west to print an error when attempting to parse the manifest data.

Manifest Imports

You can use the import key briefly described above to include projects from other manifest files in your west.yml. This key can be either a project or self section attribute:

manifest:
  projects:
    - name: some-project
      import: ...
  self:
    import: ...

You can use a “self: import:” to load additional files from the repository containing your west.yml. You can use a “project: … import:” to load additional files defined in that project’s Git history.

West resolves the final manifest from individual manifest files in this order:

  1. imported files in self

  2. your west.yml file

  3. imported files in projects

During resolution, west ignores projects which have already been defined in other files. For example, a project named foo in your west.yml makes west ignore other projects named foo imported from your projects list.

The import key can be a boolean, path, mapping, or sequence. We’ll describe these in order, using examples:

A more formal description of how this works is last, after the examples.

Troubleshooting Note

If you’re using this feature and find west’s behavior confusing, try resolving your manifest to see the final results after imports are done.

Option 1: Boolean

This is the easiest way to use import.

If import is true as a projects attribute, west imports projects from the west.yml file in that project’s root directory. If it’s false or missing, it has no effect. For example, this manifest would import west.yml from the p1 git repository at revision v1.0:

manifest:
  # ...
  projects:
    - name: p1
      revision: v1.0
      import: true    # Import west.yml from p1's v1.0 git tag
    - name: p2
      import: false   # Nothing is imported from p2.
    - name: p3        # Nothing is imported from p3 either.

It’s an error to set import to either true or false inside self, like this:

manifest:
  # ...
  self:
    import: true  # Error

Example 1.1: Downstream of a Zephyr release

You have a source code repository you want to use with Zephyr v1.14.1 LTS. You want to maintain the whole thing using west. You don’t want to modify any of the mainline repositories.

In other words, the west workspace you want looks like this:

my-downstream/
├── .west/                     # west directory
├── zephyr/                    # mainline zephyr repository
│   └── west.yml               # the v1.14.1 version of this file is imported
├── modules/                   # modules from mainline zephyr
│   ├── hal/
│   └── [...other directories..]
├── [ ... other projects ...]  # other mainline repositories
└── my-repo/                   # your downstream repository
    ├── west.yml               # main manifest importing zephyr/west.yml v1.14.1
    └── [...other files..]

You can do this with the following my-repo/west.yml:

# my-repo/west.yml:
manifest:
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
  projects:
    - name: zephyr
      remote: zephyrproject-rtos
      revision: v1.14.1
      import: true

You can then create the workspace on your computer like this, assuming my-repo is hosted at https://git.example.com/my-repo:

west init -m https://git.example.com/my-repo my-downstream
cd my-downstream
west update

After west init, my-downstream/my-repo will be cloned.

After west update, all of the projects defined in the zephyr repository’s west.yml at revision v1.14.1 will be cloned into my-downstream as well.

You can add and commit any code to my-repo you please at this point, including your own Zephyr applications, drivers, etc. See Application Development.

Example 1.2: “Rolling release” Zephyr downstream

This is similar to Example 1.1: Downstream of a Zephyr release, except we’ll use revision: master for the zephyr repository:

# my-repo/west.yml:
manifest:
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
  projects:
    - name: zephyr
      remote: zephyrproject-rtos
      revision: master
      import: true

You can create the workspace in the same way:

west init -m https://git.example.com/my-repo my-downstream
cd my-downstream
west update

This time, whenever you run west update, the special manifest-rev branch in the zephyr repository will be updated to point at a newly fetched master branch tip from the URL https://github.com/zephyrproject-rtos/zephyr.

The contents of zephyr/west.yml at the new manifest-rev will then be used to import projects from Zephyr. This lets you stay up to date with the latest changes in the Zephyr project. The cost is that running west update will not produce reproducible results, since the remote master branch can change every time you run it.

It’s also important to understand that west ignores your working tree’s zephyr/west.yml entirely when resolving imports. West always uses the contents of imported manifests as they were committed to the latest manifest-rev when importing from a project.

You can only import manifest from the file system if they are in your manifest repository’s working tree. See Example 2.2: Downstream with directory of manifest files for an example.

Example 1.3: Downstream of a Zephyr release, with module fork

This manifest is similar to the one in Example 1.1: Downstream of a Zephyr release, except it:

  • is a downstream of Zephyr 2.0

  • includes a downstream fork of the modules/hal/nordic module which was included in that release

# my-repo/west.yml:
manifest:
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
    - name: my-remote
      url-base: https://git.example.com
  projects:
    - name: hal_nordic         # higher precedence
      remote: my-remote
      revision: my-sha
      path: modules/hal/nordic
    - name: zephyr
      remote: zephyrproject-rtos
      revision: v2.0.0
      import: true             # imported projects have lower precedence

# subset of zephyr/west.yml contents at v2.0.0:
manifest:
  defaults:
    remote: zephyrproject-rtos
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
  projects:
  # ...
  - name: hal_nordic           # lower precedence, values ignored
    path: modules/hal/nordic
    revision: another-sha

With this manifest file, the project named hal_nordic:

  • is cloned from https://git.example.com/hal_nordic instead of https://github.com/zephyrproject-rtos/hal_nordic.

  • is updated to commit my-sha by west update, instead of the mainline commit another-sha

In other words, when your top-level manifest defines a project, like hal_nordic, west will ignore any other definition it finds later on while resolving imports.

This does mean you have to copy the path: modules/hal/nordic value into my-repo/west.yml when defining hal_nordic there. The value from zephyr/west.yml is ignored entirely. See Resolving Manifests for troubleshooting advice if this gets confusing in practice.

When you run west update, west will:

  • update zephyr’s manifest-rev to point at the v2.0.0 tag

  • import zephyr/west.yml at that manifest-rev

  • locally check out the v2.0.0 revisions for all zephyr projects except hal_nordic

  • update hal_nordic to my-sha instead of another-sha

Option 2: Relative path

The import value can also be a relative path to a manifest file or a directory containing manifest files. The path is relative to the root directory of the projects or self repository the import key appears in.

Here is an example:

manifest:
  projects:
    - name: project-1
      revision: v1.0
      import: west.yml
    - name: project-2
      revision: master
      import: p2-manifests
  self:
    import: submanifests

This will import the following:

  • the contents of project-1/west.yml at manifest-rev, which points at tag v1.0 after running west update

  • any YAML files in the directory tree project-2/p2-manifests at the latest master, as fetched by west update, sorted by file name

  • YAML files in submanifests in your manifest repository, as they appear on your file system, sorted by file name

Notice how projects imports get data from Git using manifest-rev, while self imports get data from your file system. This is because as usual, west leaves version control for your manifest repository up to you.

Example 2.1: Downstream of a Zephyr release with explicit path

This is an explicit way to write an equivalent manifest to the one in Example 1.1: Downstream of a Zephyr release.

manifest:
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
  projects:
    - name: zephyr
      remote: zephyrproject-rtos
      revision: v1.14.1
      import: west.yml

The setting import: west.yml means to use the file west.yml inside the zephyr project. This example is contrived, but shows the idea.

This can be useful in practice when the name of the manifest file you want to import is not west.yml.

Example 2.2: Downstream with directory of manifest files

Your Zephyr downstream has a lot of additional repositories. So many, in fact, that you want to split them up into multiple manifest files, but keep track of them all in a single manifest repository, like this:

my-repo/
├── submanifests
│   ├── 01-libraries.yml
│   ├── 02-vendor-hals.yml
│   └── 03-applications.yml
└── west.yml

You want to add all the files in my-repo/submanifests to the main manifest file, my-repo/west.yml, in addition to projects in zephyr/west.yml. You want to track the latest mainline master instead of using a fixed revision.

Here’s how:

# my-repo/west.yml:
manifest:
  remotes:
    - name: zephyrproject-rtos
      url-base: https://github.com/zephyrproject-rtos
  projects:
    - name: zephyr
      remote: zephyrproject-rtos
      import: true
  self:
    import: submanifests

Manifest files are imported in this order during resolution:

  1. my-repo/submanifests/01-libraries.yml

  2. my-repo/submanifests/02-vendor-hals.yml

  3. my-repo/submanifests/03-applications.yml

  4. my-repo/west.yml

  5. zephyr/west.yml

Note

The .yml file names are prefixed with numbers in this example to make sure they are imported in the specified order.

You can pick arbitrary names. West sorts files in a directory by name before importing.

Notice how the manifests in submanifests are imported before my-repo/west.yml and zephyr/west.yml. In general, an import in the self section is processed before the manifest files in projects and the main manifest file.

This means projects defined in my-repo/submanifests take highest precedence. For example, if 01-libraries.yml defines hal_nordic, the project by the same name in zephyr/west.yml is simply ignored. As usual, see Resolving Manifests for troubleshooting advice.

This may seem strange, but it allows you to redefine projects “after the fact”, as we’ll see in the next example.

Example 2.3: Continuous Integration overrides

Your continuous integration system needs to fetch and test multiple repositories in your west workspace from a developer’s forks instead of your mainline development trees, to see if the changes all work well together.

Starting with Example 2.2: Downstream with directory of manifest files, the CI scripts add a file 00-ci.yml in my-repo/submanifests, with these contents:

# my-repo/submanifests/00-ci.yml:
manifest:
  projects:
    - name: a-vendor-hal
      url: https://github.com/a-developer/hal
      revision: a-pull-request-branch
    - name: an-application
      url: https://github.com/a-developer/application
      revision: another-pull-request-branch

The CI scripts run west update after generating this file in my-repo/submanifests. The projects defined in 00-ci.yml have higher precedence than other definitions in my-repo/submanifests, because the name 00-ci.yml comes before the other file names.

Thus, west update always checks out the developer’s branches in the projects named a-vendor-hal and an-application, even if those same projects are also defined elsewhere.

Option 3: Mapping

The import key can also contain a mapping with the following keys:

  • file: Optional. The name of the manifest file or directory to import. This defaults to west.yml if not present.

  • name-whitelist: Optional. If present, a name or sequence of project names to include.

  • path-whitelist: Optional. If present, a path or sequence of project paths to match against. This is a shell-style globbing pattern, currently implemented with pathlib. Note that this means case sensitivity is platform specific.

  • name-blacklist: Optional. Like name-whitelist, but contains project names to exclude rather than include.

  • path-blacklist: Optional. Like path-whitelist, but contains project paths to exclude rather than include.

  • path-prefix: Optional (new in v0.8.0). If given, this will be prepended to the project’s path in the workspace, as well as the paths of any imported projects. This can be used to place these projects in a subdirectory of the workspace.

Whitelists override blacklists if both are given. For example, if a project is blacklisted by path, then whitelisted by name, it will still be imported.

Example 3.1: Downstream with name whitelist

Here is a pair of manifest files, representing a mainline and a downstream. The downstream doesn’t want to use all the mainline projects, however. We’ll assume the mainline west.yml is hosted at https://git.example.com/mainline/manifest.

# mainline west.yml:
manifest:
  projects:
    - name: mainline-app                # included
      path: examples/app
      url: https://git.example.com/mainline/app
    - name: lib
      path: libraries/lib
      url: https://git.example.com/mainline/lib
    - name: lib2                        # included
      path: libraries/lib2
      url: https://git.example.com/mainline/lib2

# downstream west.yml:
manifest:
  projects:
    - name: mainline
      url: https://git.example.com/mainline/manifest
      import:
        name-whitelist:
          - mainline-app
          - lib2
    - name: downstream-app
      url: https://git.example.com/downstream/app
    - name: lib3
      path: libraries/lib3
      url: https://git.example.com/downstream/lib3

An equivalent manifest in a single file would be:

manifest:
  projects:
    - name: mainline
      url: https://git.example.com/mainline/manifest
    - name: downstream-app
      url: https://git.example.com/downstream/app
    - name: lib3
      path: libraries/lib3
      url: https://git.example.com/downstream/lib3
    - name: mainline-app                   # imported
      path: examples/app
      url: https://git.example.com/mainline/app
    - name: lib2                           # imported
      path: libraries/lib2
      url: https://git.example.com/mainline/lib2

If a whitelist had not been used, the lib project from the mainline manifest would have been imported.

Example 3.2: Downstream with path whitelist

Here is an example showing how to whitelist mainline’s libraries only, using path-whitelist.

# mainline west.yml:
manifest:
  projects:
    - name: app
      path: examples/app
      url: https://git.example.com/mainline/app
    - name: lib
      path: libraries/lib                  # included
      url: https://git.example.com/mainline/lib
    - name: lib2
      path: libraries/lib2                 # included
      url: https://git.example.com/mainline/lib2

# downstream west.yml:
manifest:
  projects:
    - name: mainline
      url: https://git.example.com/mainline/manifest
      import:
        path-whitelist: libraries/*
    - name: app
      url: https://git.example.com/downstream/app
    - name: lib3
      path: libraries/lib3
      url: https://git.example.com/downstream/lib3

An equivalent manifest in a single file would be:

manifest:
  projects:
    - name: lib                          # imported
      path: libraries/lib
      url: https://git.example.com/mainline/lib
    - name: lib2                         # imported
      path: libraries/lib2
      url: https://git.example.com/mainline/lib2
    - name: mainline
      url: https://git.example.com/mainline/manifest
    - name: app
      url: https://git.example.com/downstream/app
    - name: lib3
      path: libraries/lib3
      url: https://git.example.com/downstream/lib3

Example 3.3: Downstream with path blacklist

Here’s an example showing how to blacklist all vendor HALs from mainline by common path prefix in the workspace, add your own version for the chip you’re targeting, and keep everything else.

# mainline west.yml:
manifest:
  defaults:
    remote: mainline
  remotes:
    - name: mainline
      url-base: https://git.example.com/mainline
  projects:
    - name: app
    - name: lib
      path: libraries/lib
    - name: lib2
      path: libraries/lib2
    - name: hal_foo
      path: modules/hals/foo     # excluded
    - name: hal_bar
      path: modules/hals/bar     # excluded
    - name: hal_baz
      path: modules/hals/baz     # excluded

# downstream west.yml:
manifest:
  projects:
    - name: mainline
      url: https://git.example.com/mainline/manifest
      import:
        path-blacklist: modules/hals/*
    - name: hal_foo
      path: modules/hals/foo
      url: https://git.example.com/downstream/hal_foo

An equivalent manifest in a single file would be:

manifest:
  defaults:
    remote: mainline
  remotes:
    - name: mainline
      url-base: https://git.example.com/mainline
  projects:
    - name: app                  # imported
    - name: lib                  # imported
      path: libraries/lib
    - name: lib2                 # imported
      path: libraries/lib2
    - name: mainline
      repo-path: https://git.example.com/mainline/manifest
    - name: hal_foo
      path: modules/hals/foo
      url: https://git.example.com/downstream/hal_foo

Example 3.4: Import into a subdirectory

You want to import a manifest and its projects, placing everything into a subdirectory of your west workspace.

For example, suppose you want to import this manifest from project foo, adding this project and its projects bar and baz to your workspace:

# foo/west.yml:
manifest:
  defaults:
    remote: example
  remotes:
    - name: example
      url-base: https://git.example.com
  projects:
    - name: bar
    - name: baz

Instead of importing these into the top level workspace, you want to place all three project repositories in an external-code subdirectory, like this:

workspace/
└── external-code/
    ├── foo/
    ├── bar/
    └── baz/

You can do this using this manifest:

manifest:
  projects:
    - name: foo
      url: https://git.example.com/foo
      import:
        path-prefix: external-code

An equivalent manifest in a single file would be:

# foo/west.yml:
manifest:
  defaults:
    remote: example
  remotes:
    - name: example
      url-base: https://git.example.com
  projects:
    - name: foo
      path: external-code/foo
    - name: bar
      path: external-code/bar
    - name: baz
      path: external-code/baz

Option 4: Sequence

The import key can also contain a sequence of files, directories, and mappings.

Example 4.1: Downstream with sequence of manifest files

This example manifest is equivalent to the manifest in Example 2.2: Downstream with directory of manifest files, with a sequence of explicitly named files.

# my-repo/west.yml:
manifest:
  projects:
    - name: zephyr
      url: https://github.com/zephyrproject-rtos/zephyr
      import: west.yml
  self:
    import:
      - submanifests/01-libraries.yml
      - submanifests/02-vendor-hals.yml
      - submanifests/03-applications.yml

Example 4.2: Import order illustration

This more complicated example shows the order that west imports manifest files:

# my-repo/west.yml
manifest:
  # ...
  projects:
    - name: my-library
    - name: my-app
    - name: zephyr
      import: true
    - name: another-manifest-repo
      import: submanifests
  self:
    import:
      - submanifests/libraries.yml
      - submanifests/vendor-hals.yml
      - submanifests/applications.yml
  defaults:
    remote: my-remote

For this example, west resolves imports in this order:

  1. the listed files in my-repo/submanifests are first, in the order they occur (e.g. libraries.yml comes before applications.yml, since this is a sequence of files), since the self: import: is always imported first

  2. my-repo/west.yml is next (with projects my-library etc. as long as they weren’t already defined somewhere in submanifests)

  3. zephyr/west.yml is after that, since that’s the first import key in the projects list in my-repo/west.yml

  4. files in another-manifest-repo/submanifests are last (sorted by file name), since that’s the final project import

Manifest Import Details

This section describes how west imports a manifest file a bit more formally.

Overview

A west manifest’s projects and self sections can have import keys, like so:

# Top-level west.yml.
manifest:
  # ...
  projects:
    - name: foo
      revision: rev-1
      import: import-1
    - name: bar
      revision: rev-2
      import: import-2
    # ...
    - name: baz
      revision: rev-N
      import: import-N
  self:
    import: self-import

Import keys are optional. If any of import-1, ..., import-N are missing, west will not import additional manifest data from that project. If self-import is missing, no additional files in the manifest repository (beyond the top-level west.yml) are imported.

The ultimate outcome of resolving manifest imports is a final list of projects, which is produced by combining the projects defined in the top-level file with those defined in imported files. Importing is done in this order:

  1. Manifests from self-import are imported first.

  2. The top-level manifest file’s projects are added in next.

  3. Manifests from import-1, …, import-N, are imported in that order.

This process recurses if necessary.

Projects are identified by name. If the same name occurs in multiple manifests, the first definition is used, and subsequent definitions are ignored. For example, if import-1 contains a project named bar, that is ignored, because the top-level west.yml has already defined a project by that name.

The contents of files named by import-1 through import-N are imported from Git at the latest manifest-rev revisions in their projects. These revisions can be updated to the values rev-1 through rev-N by running west update. If any manifest-rev reference is missing or out of date, west update also fetches project data from the remote fetch URL and updates the reference.

Also note that all imported manifests, from the root manifest to the repository which defines a project P, must be up to date in order for west to update P itself. For example, this means west update P would update manifest-rev in the baz project if baz/west.yml defines P, as well as updating the manifest-rev branch in the local git clone of P. Confusingly, the update of baz may result in the removal of P from baz/west.yml, which would cause west update P to fail with an unrecognized project!

For this reason, it’s usually best to run plain west update to avoid errors if you use manifest imports. By default, west won’t fetch any project data over the network if a project’s revision is a SHA or tag which is already available locally, so updating the extra projects shouldn’t take too much time unless it’s really needed. See the documentation for the update.fetch configuration option for more information.

If an imported manifest file has a west-commands: definition in its self: section, the extension commands defined there are added to the set of available extensions at the time the manifest is imported. They will thus take precedence over any extension commands with the same names added later on.

When an individual import key refers to multiple manifest files, they are processed in this order:

  • If the value is a relative path naming a directory (or a map whose file is a directory), the manifest files it contains are processed in lexicographic order – i.e., sorted by file name.

  • If the value is a sequence, its elements are recursively imported in the order they appear.

Manifest Command

The west manifest command can be used to manipulate manifest files. It takes an action, and action-specific arguments.

The following sections describe each action and provides a basic signature for simple uses. Run west manifest --help for full details on all options.

Resolving Manifests

The --resolve action outputs a single manifest file equivalent to your current manifest and all its imported manifests:

west manifest --resolve [-o outfile]

The main use for this action is to see the “final” manifest contents after performing any imports.

To print detailed information about each imported manifest file and how projects are handled during manifest resolution, set the maximum verbosity level using -v:

west -v manifest --resolve

Freezing Manifests

The --freeze action outputs a frozen manifest:

west manifest --freeze [-o outfile]

A “frozen” manifest is a manifest file where every project’s revision is a SHA. You can use --freeze to produce a frozen manifest that’s equivalent to your current manifest file. The -o option specifies an output file; if not given, standard output is used.

Validating Manifests

The --validate action either succeeds if the current manifest file is valid, or fails with an error:

west manifest --validate

The error message can help diagnose errors.

Get the manifest path

The --path action prints the path to the top level manifest file:

west manifest --path

The output is something like /path/to/workspace/west.yml. The path format depends on your operating system.