VCU

Vehicle Control Unit firmware (STM32G474) — and the reference board layout for the repo.

Targets

Target	What
:vcu	Firmware ELF (plus :vcu.elf / :vcu.hex / :vcu.bin).
:openocd	bazel run — flash over ST-Link.
:dfu	bazel run — flash over USB DFU.
:vcu_app_test	App logic under googletest against LHAL host fakes.
:vcu_sim	Interactive host sim (bazel run --config=local).
:release	elf/bin/hex bundle for CI artifacts.

Layout

• App/ — application logic (vcu::App), a plain cc_library depending only on //drivers/lhal. The same code links into the firmware, the host test, and the sim; see the LHAL README for the pattern.
• Board/ — hand-written bring-up: main.cpp configures clocks, pins, and peripheral handles at the ST HAL level, wraps them in LHAL adapters, and hands them to the app. Owned by us; formatted normally.
• Core/ — CubeMX-generated from VCU.ioc; "Generate Code" is safe to run any time. VCU.ioc sets ProjectManager.NoMain=true, so the generated main.c has no main() — it provides SystemClock_Config() and Error_Handler(), which the firmware compiles and uses (clock changes made in CubeMX apply automatically; lhal::stm32::InitCore() calls the generated clock config). Hand-edit only inside USER CODE sections.
• STM32G474XX_FLASH.ld / startup_stm32g474xx.s — linker script and startup for the G474, passed to firmware_project.

The BUILD.bazel here is the canonical example of a firmware_project call — what it generates and every option is documented in tools/firmware.