Reviewed on: 2025-06-24
Power Rust Driver is an example that showcase how to write a Rust driver that implements power functionality.
To include the driver to your build, append --with //examples/drivers:drivers to your fx set command. For example:
$ fx set core.x64 --with //examples/drivers:drivers $ fx build
Register the driver by running this command
$ ffx driver register fuchsia-pkg://fuchsia.com/power_rust_driver#meta/power_rust_driver.cm
Verify that fuchsia-pkg://fuchsia.com/power_rust_driver#meta/power_rust_driver.cm shows up in the list after running this command
ffx driver list
Add a test node that binds to the driver:
$ ffx driver test-node add my_node gizmo.example.TEST_NODE_ID=power_rust_driver
Run the following command to verify that the driver is bound to the node:
$ ffx driver list-devices -v my_node
You should see something like this:
Name : my_node Moniker : dev.my_node Driver : fuchsia-pkg://fuchsia.com/power_rust_driver#meta/power_rust_driver.cm 1 Properties [ 1/ 1] : Key "gizmo.example.TEST_NODE_ID" Value "power_rust_driver" 0 Offers
If you want to explore the driver lifecycle and test the driver's stop functions, stop the driver by removing the node:
$ ffx driver test-node remove my_node
View the driver logs with ffx log --filter power_rust_driver to see the execution order of the driver functions.
Include the tests to your build by appending --with //examples/drivers:tests to your fx set command. For example:
$ fx set core.x64 --with //examples/drivers:drivers --with //examples:tests $ fx build
Run unit tests with the command:
$ fx test power-rust-driver
The tests run the power rust driver and then invoke the suspend and resume hooks.
The core implementation is in src/lib.rs