CONTIKI_ARM_DIRS += cortex-m/cm4

CFLAGS += -mcpu=cortex-m4

LDFLAGS += -mcpu=cortex-m4
LDFLAGS += -T $(LDSCRIPT)
LDFLAGS += -Wl,--gc-sections,--sort-section=alignment
LDFLAGS += -Wl,-Map=$(CONTIKI_NG_PROJECT_MAP),--cref,--no-warn-mismatch

OBJCOPY_FLAGS += --gap-fill 0xff

### Build syscalls for newlib
MODULES += os/lib/newlib

CPU_STARTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(CPU_START_SOURCEFILES)}}

### Compilation rules
CUSTOM_RULE_LINK = 1

### Resolve any potential circular dependencies between the linked libraries
### See: https://stackoverflow.com/questions/5651869/gcc-what-are-the-start-group-and-end-group-command-line-options/5651895
TARGET_LIBFLAGS := -Wl,--start-group $(TARGET_LIBFILES) -Wl,--end-group

%.elf: $(CPU_STARTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(CONTIKI_NG_TARGET_LIB) $(TARGET_LIBS)
	$(TRACE_LD)
	$(Q)$(LD) $(LDFLAGS) ${filter %.o %.a,$^} $(TARGET_LIBFLAGS) -o $@

include $(CONTIKI)/arch/cpu/arm/cortex-m/Makefile.cortex-m