#  Copyright (c) 2021 Arm Limited. All rights reserved.
#  SPDX-License-Identifier: Apache-2.0
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

# Generic Makefile target for ARM Cortex M builds.
# For more info see: tensorflow/lite/micro/cortex_m_generic/README.md
ifeq ($(TARGET),$(filter $(TARGET), cortex_m_ethos_eval))
  FLOAT := soft
  GCC_TARGET_ARCH := $(TARGET_ARCH)

  ifeq ($(TARGET_ARCH), cortex-m0)
    CORE=M0
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M0

  else ifeq ($(TARGET_ARCH), cortex-m3)
    CORE=M3
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M3

  else ifeq ($(TARGET_ARCH), cortex-m33)
    CORE=M33
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M33
    TARGET_SPECIFIC_FLAGS += -D__DSP_PRESENT=1 -D__FPU_PRESENT=1 -D__VTOR_PRESENT=1 -D__FPU_USED=1
    FLOAT=hard

  else ifeq ($(TARGET_ARCH), cortex-m33+nodsp)
    CORE=M33
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M33.no_dsp.no_fp

  else ifeq ($(TARGET_ARCH), cortex-m4)
    CORE=M4
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M4.no_fp
    GCC_TARGET_ARCH := cortex-m4+nofp

  else ifeq ($(TARGET_ARCH), cortex-m4+fp)
    CORE=M4
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M4
    TARGET_SPECIFIC_FLAGS += -D__FPU_PRESENT=1
    FLOAT=hard
    GCC_TARGET_ARCH := cortex-m4

  else ifeq ($(TARGET_ARCH), cortex-m55)
    CORE=M55
    ARM_LDFLAGS := -Wl,--cpu=8.1-M.Main.mve.fp
    TARGET_SPECIFIC_FLAGS += -D__DSP_PRESENT=1 -D__FPU_PRESENT=1
    FLOAT=hard

  else ifeq ($(TARGET_ARCH), cortex-m55+nodsp+nofp)
    CORE=M55
    ARM_LDFLAGS := -Wl,--cpu=8.1-M.Main.mve.no_dsp.no_fp

  else ifeq ($(TARGET_ARCH), cortex-m55+nofp)
    CORE=M55
    ARM_LDFLAGS := -Wl,--cpu=8.1-M.Main.mve.no_fp
    TARGET_SPECIFIC_FLAGS += -D__DSP_PRESENT=1

  else ifeq ($(TARGET_ARCH), cortex-m7)
    CORE=M7
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M7.no_fp
    GCC_TARGET_ARCH := cortex-m7+nofp

  else ifeq ($(TARGET_ARCH), cortex-m7+fp)
    CORE=M7
    ARM_LDFLAGS := -Wl,--cpu=Cortex-M7
    FLOAT=hard
    GCC_TARGET_ARCH := cortex-m7

  else
    $(error "TARGET_ARCH=$(TARGET_ARCH) is not supported")
  endif

  ifneq ($(filter cortex-m55%,$(TARGET_ARCH)),)
    # soft-abi=soft disables MVE - use softfp instead for M55.
    ifeq ($(FLOAT),soft)
      FLOAT=softfp
    endif
  endif

  # Toolchain specfic flags
  ifeq ($(TOOLCHAIN), armclang)
    CXX_TOOL  := armclang
    CC_TOOL   := armclang
    AR_TOOL   := armar
    LD        := armlink

    FLAGS_ARMC = \
      --target=arm-arm-none-eabi \
      -mcpu=$(TARGET_ARCH)

    # For debug, include specific dwarf format symbols
    ifeq ($(BUILD_TYPE), debug)
      ifneq ($(ARMCLANG_DEBUG_DWARF_LEVEL),)
        FLAGS_ARMC += -gdwarf-$(ARMCLANG_DEBUG_DWARF_LEVEL)
      endif
    endif

    CXXFLAGS += $(FLAGS_ARMC)
    CCFLAGS += $(FLAGS_ARMC)
    LDFLAGS += $(ARM_LDFLAGS)

    # Arm Compiler will not link the Math library (see below), therefore we're filtering it out.
    # See Fatal error: L6450U: Cannot find library m:
    # "Arm Compiler is designed to run in a bare metal environment,
    # and automatically includes implementations of these functions,
    # and so no such flag is necessary."
    # https://developer.arm.com/documentation/100891/0611/troubleshooting/general-troubleshooting-advice
    MICROLITE_LIBS := $(filter-out -lm,$(MICROLITE_LIBS))

  else ifeq ($(TOOLCHAIN), gcc)
    export PATH := $(MAKEFILE_DIR)/downloads/gcc_embedded/bin/:$(PATH)
    DOWNLOAD_RESULT := $(shell $(MAKEFILE_DIR)/arm_gcc_download.sh ${MAKEFILE_DIR}/downloads)
    ifneq ($(DOWNLOAD_RESULT), SUCCESS)
      $(error Something went wrong with the GCC download: $(DOWNLOAD_RESULT))
    endif

    TARGET_TOOLCHAIN_PREFIX := arm-none-eabi-

    FLAGS_GCC = -mcpu=$(GCC_TARGET_ARCH) -mfpu=auto
    CXXFLAGS += $(FLAGS_GCC)
    CCFLAGS += $(FLAGS_GCC)

  else
    $(error "TOOLCHAIN=$(TOOLCHAIN) is not supported.")
  endif

  PLATFORM_FLAGS = \
    -DTF_LITE_MCU_DEBUG_LOG \
    -mthumb \
    -mfloat-abi=$(FLOAT) \
    -funsigned-char \
    -mlittle-endian \
    -Wno-type-limits \
    -Wno-unused-private-field \
    -fomit-frame-pointer \
    -MD \
    -DCPU_CORTEX_$(CORE)=1 \
    $(TARGET_SPECIFIC_FLAGS)

  # Common + C/C++ flags
  CXXFLAGS += $(PLATFORM_FLAGS)
  CCFLAGS += $(PLATFORM_FLAGS)

endif