LHRe

Longhorn Racing Electric's monorepo: firmware for every ECU on the car, the hardware abstraction layer it's built on, and the tooling to build, test, and flash it all with Bazel.

Layout

Directory	What lives there
drivers/	Hardware. LHAL (our platform-independent HAL) and vendor HAL packages.
lib/	Platform-agnostic C++ that builds on host and target (ring buffers, CRC, CAN pack/unpack, …), with colocated tests.
apps/	Host-side software: telemetry, dashboards, gateways.
boards/	Per-ECU firmware projects (boards/VCU is the reference layout).
tools/	Build and dev tooling: firmware_project, flashing, formatting.

There are no per-year directories: main is always the current car, and past seasons live in tags and maintenance branches (see CONTRIBUTING.md).

Prerequisites

• Bazelisk (installs the pinned Bazel from .bazelversion automatically)
• Git

That's it — compilers (ARM GCC for firmware, LLVM for host code) are hermetic and downloaded by Bazel. No Xcode, MSVC, or system GCC needed for C++. STM32CubeMX is only needed when changing a board's peripheral configuration.

On Windows, builds run locally instead of on remote executors; for full remote execution use WSL2 (see the comments in .bazelrc).

First steps

Build the VCU firmware:

bazel build //boards/VCU:vcu

Run all tests (on the BuildBuddy Linux executors by default):

bazel test //...

Run the VCU simulator on your machine:

bazel run --config=local //boards/VCU:vcu_sim

Flash a board over ST-Link:

bazel run //boards/VCU:openocd

Remote build setup (BuildBuddy)

Builds stream to and cache on lhre.buildbuddy.io. To authenticate, copy .bazelrc.user.example to .bazelrc.user (gitignored) and paste your API key from BuildBuddy → Settings → API keys — ask a software lead for an invite to the org.

No key, or no internet? --config=local builds entirely on your machine.