Drivers provide software interfaces for communicating with hardware (or virtual) devices that are embedded in or connected to a system. In Fuchsia, drivers are user-space components running within the system's component topology, and the driver framework builds on the concepts and tools provided by the component framework. Drivers interact with each other and non-driver components using capabilities and connections established over FIDL.
In this codelab, you'll build a Fuchsia driver component that targets a virtual
device built into QEMU (which underpins the
Fuchsia emulator) named edu, which is an educational
device for writing drivers that computes the factorial of a given integer.
You'll also explore how to interact with drivers using the tools provided with
the Fuchsia SDK.
What you'll learn
- Discovering and binding to device nodes
- Registering and loading a new device driver
- Interacting with a running device driver
What you'll need
An x64-based machine running Linux or macOS
A configured Fuchsia SDK environment
Emulator product bundle for
core.x64
Before you begin
As part of the prerequisites, you created a Bazel workspace in the
fuchsia-drivers/ directory. This is the directory that contains a
WORKSPACE.bazel file and it represents the root of the workspace. Throughout
the codelab, this root directory is referred to using the // prefix. For
example, the path //fuchsia-codelab represents a directory named
fuchsia-codelab at the root of the Bazel workspace.
The Bazel workspace is also pre-configured with development tools provided by
the Fuchsia SDK in the tools/ directory. This codelab assumes you are using
the SDK tools from within your Bazel workspace, so consider updating your PATH
to include the SDK's tools/ directory or create a temporary alias using the
following commands:
alias ffx=tools/ffx
alias bazel=tools/bazel