# Compilation flags
ARCH_SPLIT = $(subst -, ,$(ARCH))
ISA        = $(word 1,$(ARCH_SPLIT))
PLATFORM   = $(word 2,$(ARCH_SPLIT))

ifeq ($(ISA), mips32)
CROSS_COMPILE = mips-linux-gnu-
endif

ifeq ($(ISA), riscv32)
CROSS_COMPILE = riscv32-unknown-elf-
endif

ifeq ($(ISA), riscv64)
CROSS_COMPILE = riscv64-unknown-linux-gnu-
endif

AS = $(CROSS_COMPILE)gcc
CC = $(CROSS_COMPILE)gcc
CXX = $(CROSS_COMPILE)g++
LD = $(CROSS_COMPILE)ld
OBJCOPY = $(CROSS_COMPILE)objcopy
READELF = $(CROSS_COMPILE)readelf

ISA_DEF = __ISA_$(shell echo $(ISA) | tr a-z A-Z)__

INCLUDES  = $(addprefix -I, $(INC_DIR)) -I$(AM_HOME)/am/
INCLUDES += -I$(AM_HOME)/am/arch/$(ARCH)/include
CFLAGS   += -std=gnu99 -O2 -MMD -Wall -Werror -ggdb $(INCLUDES) -D$(ISA_DEF) -fno-builtin
CXXFLAGS += -std=c++11 -O2 -MMD -Wall -Werror -ggdb $(INCLUDES) -D$(ISA_DEF) -fno-builtin
ASFLAGS  +=                -MMD                     $(INCLUDES) -D$(ISA_DEF)

ifeq ($(ISA), mips32)
CFLAGS_COMMON = -fno-pic -static -fno-strict-aliasing -fno-builtin -fno-stack-protector -fno-delayed-branch -mno-abicalls -march=mips32 -mno-check-zero-division -EL -mno-llsc -mno-imadd -mno-mad
CFLAGS   += $(CFLAGS_COMMON)
CXXFLAGS += $(CFLAGS_COMMON) -ffreestanding -fno-rtti -fno-exceptions
ASFLAGS  += -march=mips32 -EL -mno-check-zero-division -O0 -mno-abicalls -fno-pic -fno-delayed-branch
endif

ifeq ($(ISA), riscv32)
# it seems that mstrict-align does not work?
CFLAGS_COMMON = -fno-pic -static -mcmodel=medany -fno-delete-null-pointer-checks -mabi=ilp32 -march=rv32i -mstrict-align
CFLAGS   += $(CFLAGS_COMMON)
CXXFLAGS += $(CFLAGS_COMMON) -ffreestanding -fno-rtti -fno-exceptions
endif

ifeq ($(ISA), riscv64)
CFLAGS_COMMON = -fno-pic -static -mcmodel=medany -fno-delete-null-pointer-checks -mabi=lp64 -march=rv64imac
CFLAGS   += $(CFLAGS_COMMON)
CXXFLAGS += $(CFLAGS_COMMON) -ffreestanding -fno-rtti -fno-exceptions
endif

ifeq ($(ISA), x86)
CFLAGS_COMMON = -m32 -fno-pic -fno-builtin -fno-stack-protector -fno-omit-frame-pointer -march=i386 -mstringop-strategy=unrolled_loop
CFLAGS   += $(CFLAGS_COMMON)
CXXFLAGS += $(CFLAGS_COMMON) -ffreestanding -fno-rtti -fno-exceptions
ASFLAGS  += -m32
endif

# Files to be compiled
OBJS = $(addprefix $(DST_DIR)/, $(addsuffix .o, $(basename $(SRCS))))

# Compilation patterns
$(DST_DIR)/%.o: %.cpp
	@mkdir -p $(dir $@)
	$(CXX) $(CXXFLAGS) -c -o $@ $<
$(DST_DIR)/%.o: %.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c -o $@ $<
$(DST_DIR)/%.o: %.S
	@mkdir -p $(dir $@)
	$(AS) $(ASFLAGS) -c -o $@ $<

# Depencies
DEPS = $(addprefix $(DST_DIR)/, $(addsuffix .d, $(basename $(SRCS))))
-include $(DEPS)

# Dependent AM and libraries
.PHONY: $(LIBS) am
am:
	$(MAKE) -C $(AM_HOME)
$(LIBS): %:
	$(MAKE) -C $(AM_HOME)/libs/$*