commit	5967d7242aaa7b246a2f37d9ffb2647faca8d3fd	[log] [tgz]
author	Austin Foxley <afoxley@pigweed.infra.roller.google.com>	Thu Oct 23 08:45:25 2025 -0700
committer	CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>	Thu Oct 23 08:45:25 2025 -0700
tree	97c56272a0615c69d268ca34f42ff7ec7feab34c
parent	48670dd0ab3253136083f29487d26d99ee78b205 [diff]

tree: 97c56272a0615c69d268ca34f42ff7ec7feab34c

README.md

Zephyr-Bazel

The way this repository works is by overlaying itself on top of Zephyr. To get started, first make sure you have Bazel‘s skylib version 1.7.1 or greater. If you don’t have it, you can use:

http_archive(
    name = "bazel_skylib",
    sha256 = "bc283cdfcd526a52c3201279cda4bc298652efa898b10b4db0837dc51652756f",
    urls = [
        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.7.1/bazel-skylib-1.7.1.tar.gz",
        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.7.1/bazel-skylib-1.7.1.tar.gz",
    ],
)

load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")

bazel_skylib_workspace()

Usage in WORKSPACE

To grab the zephyr-bazel repo, use a git_repository rule in your WORKSPACE, such as:

git_repository(
    name = "zephyr-bazel",
    remote = "https://pigweed.googlesource.com/zephyr/zephyr-bazel",
    branch = "main",
)

Once you have @zephyr-bazel, we can load the patch rule to generate the Zephyr diff that will augment Zephyr to include the BUILD.zephyr rules.

load("@zephyr-bazel//:setup.bzl", "create_zephyr_patch_file")

create_zephyr_patch_file(
    name = "zephyr-patch",
    filename = "patch.diff",
    # This is optional, use it to see what's going on under the hood
    debug = True,
)

We now have a diff file at @zephyr-patch//:patch.diff. We're ready to load Zephyr.

git_repository(
    name = "zephyr",
    remote = "https://github.com/zephyrproject-rtos/zephyr.git",
    branch = "main",
    patches = [
        "@zephyr-patch//:patch.diff",
    ],
)

The final step will be to load Zephyr's python dependencies:

load("@rules_python//python:pip.bzl", "pip_parse")

pip_parse(
    name = "py_deps",
    python_interpreter_target = interpreter,
    requirements_lock = "@@zephyr//:scripts/requirements-base.txt",
)

load("@py_deps//:requirements.bzl", zephyr_install_deps = "install_deps")

zephyr_install_deps()

Usage in bzlmod

To use zephyr-bazel in bzlmod, first add it as a dependency in your project's MODULE.bazel:

bazel_dep(name = "zephyr-bazel")
git_override(
    module_name = "zephyr-bazel",
    remote = "https://pigweed.googlesource.com/zephyr/zephyr-bazel",
    branch = "main",
)

Then use the zephyr_patch_file module extension to generate a patch file and a Bazel repo with the patch file applied:

zephyr_patch_file = use_extension("@zephyr-bazel//:setup.bzl", "zephyr_patch_file")
use_repo(zephyr_patch_file, "zephyr")

pip is required by the patched zephyr repo, so your project needs to inject it:

pip = use_extension("@rules_python//python/extensions:pip.bzl", "pip")
# Load the Zephyr pip requirements
pip.parse(
    hub_name = "pip",
    python_version = "3.11",
    requirements_lock = "@zephyr//:scripts/requirements-base.txt",
)
use_repo(pip, "pip")

inject_repo(zephyr_patch_file, "pip")

Application

In your main application, you can now use the Zephyr utilities for building your app.

load("@zephyr//:defs.bzl", "dts_cc_library")

dts_cc_library(
    name = "app_native_sim_dts",
    dts_lib = "@zephyr//boards/native/native_sim:native_sim",
)

cc_binary(
    ...
    deps = [
        ...
        "@zephyr//:zephyr",
    ] + select({
        "@platform//cpu:x86_64": [
            ":app_native_sim_dts",
            "@zephyr//include:posix",
        ],
    }),
    copts = select({
        "@platform//cpu:x86_64": [
            "-DCONFIG_ARCH_POSIX=1",
        ],
    }),
)

Examples

There is currently just 1 example, you can run it via:

$ cd examples/hello_dts
$ bazel run :app

Or, you can run the tests via:

$ cd examples/hello_dts
$ bazel test //...