roll: pigweed, pw_toolchain: pw_sys_io_baremetal_stm32f429: Add constraint

This backend will need a boolean_constraint_value because it's only
compatible with some platforms.

We'll remove the "//pw_sys_io:backend_constraint_setting" and its
associated constraint_value in a subsequent change, but need to keep it
around for a soft transition.

Original-Bug: 347998044
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/218831
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 544489798d89ed0..d6d285ab73303e4
Roller-URL: https://ci.chromium.org/b/8743859337177448897
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I75450c170132cf424a01808062dc2a35faa8af21
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/218799
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
1 file changed
tree: f613e073412339e089eb1e1a5039a5b838ecfb3c
  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!