Cleanup and finish build system

Makefile

@@ -0,0 +1,41 @@
+.PHONY: all build cmake clean format
+
+# --- Configurable variables ---
+BUILD_DIR    := build
+BUILD_TYPE   ?= Debug
+TOOLCHAIN    := gcc-arm-none-eabi.cmake
+
+# MCU target (override on command line: make build MCU_MODEL=STM32F051x8)
+MCU_MODEL    ?= STM32F072xB
+MCU_FAMILY   ?= STM32F0xx
+
+# --- Default target ---
+all: build
+
+# --- Configure step (runs CMake if build dir missing or stale) ---
+${BUILD_DIR}/build.ninja:
+	cmake \
+		-G Ninja \
+		-B ${BUILD_DIR} \
+		-DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
+		-DCMAKE_TOOLCHAIN_FILE=${TOOLCHAIN} \
+		-DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+		-DMCU_MODEL=$(MCU_MODEL) \
+		-DMCU_FAMILY=$(MCU_FAMILY)
+
+cmake: ${BUILD_DIR}/build.ninja
+
+# --- Build step ---
+build: cmake
+	cmake --build ${BUILD_DIR}
+
+# --- Format all sources ---
+SRCS := $(shell find . -type f \( -name '*.[ch]' -o -name '*.[ch]pp' \))
+format: $(addsuffix .format,${SRCS})
+
+%.format: %
+	clang-format -i $<
+
+# --- Clean ---
+clean:
+	rm -rf ${BUILD_DIR} compile_commands.json