Managing the Memfault SDK as a Git Submodule

Installing the SDK as a Git Submodule

Using a Git Submodule to manage the Memfault SDK can be useful, especially if your build system doesn't natively support using Git Repositories as sources.

To add the Memfault SDK as a Git Submodule:

# the last argument sets the path to the submodule, here "third_party/memfault-firmware-sdk"
git submodule add https://github.com/memfault/memfault-firmware-sdk.git third_party/memfault-firmware-sdk

The submodule add is now staged in the Git index, and can be committed as usual.

Specifying the version of the Memfault SDK

By default, the submodule add command will checkout the latest commit on the default branch.

See the Memfault SDK releases page for the latest release version:

https://github.com/memfault/memfault-firmware-sdk/releases

To select a specific tag for the submodule, follow these commands:

# change directory to the submodule
cd path/to/memfault/submodule

# checkout a particular tag
git checkout <tag>

# cd back to the parent repo root
cd -

# stage the updated submodule to the index (and commit if appropriate)
git add path/to/memfault/submodule

Considerations when cloning the parent repo

To initialize the repo after adding a submodule, the following commands should be used:

# Option 1: clone and update in one command by using the '--recursive' flag
git clone --recursive <repo remote URL>

# Option 2: clone, then update after
git clone <repo remote URL>
cd path-to-newly-cloned-repo
git submodule update --init --recursive

To learn more about working with submodules, check out GitHub's blog post about them.