roll: pigweed, pw_toolchain: bazel: Enable bzlmod

Removes --noenable_bzlmod from Pigweed's .bazelrc and applies necessary
changes to get the build working again. Also makes Pigweed usable as a
bzlmod dependency.

Most of the file changes in this CL are Python import statement changes
required because of
https://github.com/bazelbuild/rules_python/issues/1679.

Original-Bug: b/258836641
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/211362
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 4f0412dae17b20a..00d99767eb5ad66
Roller-URL: https://ci.chromium.org/b/8741667154616515185
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I5437982f041b87873fb4d81e4113584038a3f1cf
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/225374
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
1 file changed
tree: bde3cb9dac5b667b68b48d789455a5b457488f36
  1. .github/
  2. src/
  3. targets/
  4. tools/
  5. .bazelignore
  6. .bazelrc
  7. .bazelversion
  8. .gitignore
  9. BUILD.bazel
  10. echo.bzl
  11. LICENSE
  12. pigweed.json
  13. README.md
  14. requirements.in
  15. requirements_lock.txt
  16. WORKSPACE
README.md

Pigweed: minimal Bazel example

This repository contains a minimal example of a Bazel-based Pigweed project. It's an echo application for the STM32F429 Discovery Board.

Cloning

git clone --recursive https://pigweed.googlesource.com/pigweed/quickstart/bazel

If you already cloned but forgot to include --recursive, run git submodule update --init to pull all submodules.

TODO: b/300695111 - Don't require submodules for this example.

Building

We‘ll assume you already have Bazel on your system. If you don’t, the recommended way to get it is through Bazelisk.

To build the entire project (including building the application for both the host and the STM32 Discovery Board), run

bazel build //...

To run the application locally on your machine, run,

bazel run //src:echo

Flashing

To flash the firmware to a STM32F429 Discovery Board connected to your machine, run,

bazel run //tools:flash

Note that you don't need to build the firmware first: Bazel knows that the firmware images are needed to flash the board, and will build them for you. And if you edit the source of the firmware or any of its dependencies, it will get rebuilt when you flash.

Communicating

Run,

bazel run //tools:miniterm -- /dev/ttyACM0 --filter=debug

to communicate with the board. When you transmit a character, you should get the same character back!