Port to srm32g031

Makefile

@@ -17,9 +17,6 @@ platform/stm32g0xx/system_stm32g0xx.c \
 platform/stm32g0xx/syscalls.c \
 platform/stm32g0xx/sysmem.c \
 
-ASM_SOURCES = \
-platform/stm32g0xx/startup_stm32g071rbtx.s
-
 PREFIX = arm-none-eabi-
 CC = $(PREFIX)gcc
 CXX = $(PREFIX)g++
@@ -33,8 +30,21 @@ BIN = $(CP) -O binary -S
 CPU = -mcpu=cortex-m0plus
 MCU = $(CPU) -mthumb $(FPU) $(FLOAT-ABI)
 
-C_DEFS = \
--DSTM32G071xx
+ifeq "$(SOC)" "stm32g071"
+
+C_DEFS = -DSTM32G071xx
+LDSCRIPT = platform/stm32g0xx/STM32G071RBTX_FLASH.ld
+ASM_SOURCES = platform/stm32g0xx/startup_stm32g071rbtx.s
+
+else
+ifeq "$(SOC)" "stm32g031"
+
+C_DEFS = -DSTM32G031xx
+LDSCRIPT = platform/stm32g0xx/STM32G031Y8YX_FLASH.ld
+ASM_SOURCES = platform/stm32g0xx/startup_stm32g031y8yx.s
+
+endif
+endif
 
 C_INCLUDES = \
 -I. \
@@ -52,8 +62,6 @@ endif
 
 CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)"
 
-LDSCRIPT = platform/stm32g0xx/STM32G071RBTX_FLASH.ld
-
 LIBS = -lc -lm -lnosys
 LIBDIR =
 LDFLAGS = $(MCU) -specs=nano.specs -T$(LDSCRIPT) $(LIBDIR) $(LIBS) -Wl,-Map=$(BUILD_DIR)/$(TARGET).map,--cref -Wl,--gc-sections
@@ -78,7 +86,7 @@ $(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR)
 $(BUILD_DIR)/%.o: %.s Makefile | $(BUILD_DIR)
 	$(AS) -c $(CFLAGS) $< -o $@
 
-$(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) Makefile
+$(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) | Makefile
 	$(CXX) $(OBJECTS) $(LDFLAGS) -o $@
 	$(SZ) $@