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Rust Build

Project Mu has integrated support to build Rust modules in the normal firmware build process.

Cargo make is used as a build runner to allow users to build Rust packages individually and simply on the command line similar to the way they are built during the firmware build process. It is a CLI tool that helps abstract away many of the CLI arguments necessary to build a Rust module so that developers can easily check, test, and build individual Rust packages without the need to copy and/or memorize a long list of arguments.

Based on changes in: edk2-staging/edkii-rust

Generally Getting Started with Rust

It is recommended to:

  1. Update the repo to ensure it includes the changes needed for Rust build support.

  2. Download and install Rust and cargo from Getting Started - Rust Programming Language (

  3. Verify cargo is working:

>cargo --version

  1. Install the desired Rust tool chain. The version is found in the rust-toolchain.toml file at the root of any Project Mu repository that contains Rust code.

  2. Example: 1.73.0 x86_64 toolchain

  3. Windows:

    >rustup toolchain install 1.73.0-x86_64-pc-windows-msvc

    >rustup component add rust-src --toolchain 1.73.0-x86_64-pc-windows-msvc

  4. Linux:

    >rustup toolchain install 1.73.0-x86_64-unknown-linux-gnu

    >rustup component add rust-src --toolchain 1.73.0-x86_64-unknown-linux-gnu

  5. Install cargo make

>cargo install --force cargo-make

  1. Install cargo tarpaulin

>cargo install --force cargo-tarpaulin

At this point, the essential Rust applications are installed, and a repo can begin to add and build Rust code.

Important Build and Config Files

Currently, two files are provided in Project Mu repos that play an important role in the building and formatting of Rust code in Project Mu based repositories.

  • Makefile.toml - Defines the tasks and environment settings use within the Project Mu build system to build and test code.

  • rustfmt.toml - Defines Rust formatting options used.

  • rust-toolchain.toml - Defines the exact toolchain supported for this repository

Project Mu repos have common files automatically synced from a common source in the Mu DevOps repo. Projects downstream to Project Mu are recommended to "extend" the Makefile.toml in Mu Basecore by following the instructions in the "Default Tasks and Extending" section of the cargo make documentation.

Note that the file path to the Mu Basecore file will be relative to the project's own makefile.

The rustfmt.toml and rust-toolchain.toml files synced across Project Mu repos defines the supported rust version common formatting options expected for Rust code in other Project Mu based repositories.

Dev Container (with Rust)

A container that includes Rust and Project Mu tools for a simple "out of box" development experience is available in the container registry in Mu DevOps.

Build Variations

First, the simplest case is a new user approaching a package that supports Rust modules. In that case, just build the package like "normal" (e.g., stuart build) and the "normal" build output (i.e., EFI drivers and firmware volumes) will be produced.

Build an Individual Module

cargo make build <Module Name>

The following command line options are available:

  1. -p PROFILE [development|release]. DEFAULT = development (debug)
  2. -e ARCH=[IA32|X64|AARCH64|LOCAL]. DEFAULT = X64
  3. -e TARGET_TRIPLE=[triple].

  4. ARCH=LOCAL is used to build any locally executable tools associated with a Rust library package (e.g., a dual-purpose executable and library).

  5. TARGET_TRIPLE=<triple> is used to cross-compile locally executable tools associated with a Rust library package.

  6. Note: A Rust package must be specified.

  7. The output location is:
  8. target/[x86_64-unknown-uefi|i686-unknown-uefi]/[debug|release]/module_name.[efi|rlib]

Test an Individual Module

cargo make test <Optional: Module Name>
cargo make coverage <Optional: Module Name>
  • Note: If a package is not specified, all packages will be tested. Multiple packages can be provided, comma separated.
  • cargo make coverage to generate coverage results on top of testing.

Supported Build Combinations

  1. C source + Rust source mixed in INF (Library or Module)
  2. Rust source code is supported by build rule – Rust-To-Lib-File (.rs => .lib)

  3. Limitation: Rust code cannot have external dependencies.

  4. Pure Rust Module only.

  5. A Cargo.toml file is added to the INF file [Sources] section.

  6. Rust Module build is supported by build rule – Toml-File.RUST_MODULE (Toml => .efi)

  7. Limitation: Runtime might be a problem, such as virtual address translation for Rust code internal global variables.

  8. Pure Rust Module + Pure Rust Library with Cargo Dependency.

  9. Cargo dependency means the Rust lib dependency declared in Cargo.toml.

  10. Pure Rust Module + C Library with EDK II Dependency.

  11. Rust Module build is supported by build rule – Toml-File (Toml => .lib)

  12. The EDK II dependency means the EDK II lib dependency declared in INF.

    • If a Rust module is built with C, the cargo must use staticlib. Otherwise, rlib is used.
    • A simple example that specifies staticlib in the package Cargo.toml file using crate-type = ["staticlib"] in the [lib] section is shown below.
    crate-type = ["staticlib"]
  13. C Module + Pure Rust Library with EDK II Dependency.

  14. Rust library build is supported by build rule – Toml-File. (Toml => .lib)

  15. Pure Rust Module + Pure Rust Library with EDK II Dependency.

  16. Same as (4) + (5).