cmake_minimum_required(VERSION 3.12)

# Set default RISC-V toolchain if not specified
if(NOT DEFINED RISCV_TOOLCHAIN_PATH)
    set(RISCV_TOOLCHAIN_PATH "/opt/shared/cross-toolchains/gcc13/CentOS/riscv64-unknown-elf/bin" CACHE STRING "Path to RISC-V toolchain")
endif()

# Allow override of compiler executables
if(NOT DEFINED RISCV_GCC)
    set(RISCV_GCC "/opt/shared/cross-toolchains/gcc13/CentOS/riscv64-unknown-elf/bin/riscv64-unknown-elf-gcc" CACHE STRING "RISC-V GCC compiler")
endif()

if(NOT DEFINED RISCV_GXX)
    set(RISCV_GXX "${RISCV_TOOLCHAIN_PATH}/riscv64-unknown-elf-g++" CACHE STRING "RISC-V G++ compiler")
endif()

if(NOT DEFINED RISCV_OBJCOPY)
    set(RISCV_OBJCOPY "${RISCV_TOOLCHAIN_PATH}/riscv64-unknown-elf-objcopy" CACHE STRING "RISC-V objcopy")
endif()

if(NOT DEFINED RISCV_OBJDUMP)
    set(RISCV_OBJDUMP "${RISCV_TOOLCHAIN_PATH}/riscv64-unknown-elf-objdump" CACHE STRING "RISC-V objdump")
endif()

# Set the compilers
set(CMAKE_C_COMPILER ${RISCV_GCC})
set(CMAKE_CXX_COMPILER ${RISCV_GXX})

project(Firmware)

# Define supported configurations
set(SUPPORTED_BOARDS iss)
set(SUPPORTED_ISAS "rv32i;rv32im;rv32imc;rv64i;rv64im;rv64imc;imc")
set(SUPPORTED_ABIS "ilp32;ilp32f;lp64;lp64f")

# Build target options
option(BUILD_HELLO_WORLD "Build hello-world example" ON)
option(BUILD_DHRYSTONE "Build dhrystone benchmark" OFF)
option(BUILD_COREMARK "Build coremark benchmark" OFF)
option(BUILD_ALL "Build all targets" OFF)

# If BUILD_ALL is ON, enable all targets
if(BUILD_ALL)
    set(BUILD_HELLO_WORLD ON)
    set(BUILD_DHRYSTONE ON)
    set(BUILD_COREMARK ON)
endif()

# Set default values and validate configurations
if(NOT DEFINED BOARD)
    set(BOARD iss CACHE STRING "Target board")
endif()

if(NOT DEFINED ISA)
    set(ISA imc CACHE STRING "Target ISA")
endif()

if(NOT DEFINED RISCV_ABI)
    if(ISA MATCHES "^rv64")
        set(RISCV_ABI "lp64" CACHE STRING "RISC-V ABI")
    else()
        set(RISCV_ABI "ilp32" CACHE STRING "RISC-V ABI")
    endif()
endif()

# Validate configurations
if(NOT BOARD IN_LIST SUPPORTED_BOARDS)
    message(FATAL_ERROR "Invalid BOARD specified. Supported boards: ${SUPPORTED_BOARDS}")
endif()

if(NOT ISA IN_LIST SUPPORTED_ISAS)
    message(FATAL_ERROR "Invalid ISA specified. Supported ISAs: ${SUPPORTED_ISAS}")
endif()

if(NOT RISCV_ABI IN_LIST SUPPORTED_ABIS)
    message(FATAL_ERROR "Invalid ABI specified. Supported ABIs: ${SUPPORTED_ABIS}")
endif()

# Set RISC-V architecture based on ISA
if(ISA MATCHES "^rv")
    set(RISCV_ARCH ${ISA})
else()
    # Default to rv32 for backward compatibility
    set(RISCV_ARCH "rv32${ISA}")
endif()

# Set BSP base directory
set(BSP_BASE "${CMAKE_CURRENT_SOURCE_DIR}/bare-metal-bsp")

# Global compile definitions
add_compile_definitions(BOARD_${BOARD})

# RISC-V specific compiler flags
#set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=${RISCV_ARCH}_zicsr_zifencei -mabi=${RISCV_ABI}")
#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=${RISCV_ARCH}_zicsr_zifencei -mabi=${RISCV_ABI}")

# Optional: Enable semihosting support
option(SEMIHOSTING "Enable semihosting support" OFF)
if(SEMIHOSTING)
    add_compile_definitions(SEMIHOSTING)
endif()

#create interface library for propagating compile options
add_library(global_compile_options INTERFACE)

# Compile options
target_compile_options(global_compile_options INTERFACE
    -march=${RISCV_ARCH}_zicsr_zifencei
    -mabi=${RISCV_ABI}
    -mcmodel=medany
    -O2
    -g
  #  -ffunction-sections
  #  -fdata-sections
)



message(STATUS "Building firmware with configuration:")
message(STATUS "  Board: ${BOARD}")
message(STATUS "  ISA: ${ISA} (Architecture: ${RISCV_ARCH})")
message(STATUS "  ABI: ${RISCV_ABI}")
message(STATUS "  Semihosting: ${SEMIHOSTING}")
message(STATUS "  Toolchain:")
message(STATUS "    Path: ${RISCV_TOOLCHAIN_PATH}")
message(STATUS "    C Compiler: ${CMAKE_C_COMPILER}")
message(STATUS "    C++ Compiler: ${CMAKE_CXX_COMPILER}")
message(STATUS "Targets to build:")
message(STATUS "  hello-world: ${BUILD_HELLO_WORLD}")
message(STATUS "  dhrystone: ${BUILD_DHRYSTONE}")
message(STATUS "  coremark: ${BUILD_COREMARK}")


add_subdirectory(bare-metal-bsp)

# Add subdirectories based on build options
if(BUILD_HELLO_WORLD)
    add_subdirectory(hello-world)
endif()


if(BUILD_DHRYSTONE)
    add_subdirectory(benchmarks/dhrystone)
endif()

if(BUILD_COREMARK)
    add_subdirectory(benchmarks/coremark)
endif()

# Create an all-inclusive target only if BUILD_ALL is ON
if(BUILD_ALL)
    add_custom_target(fw-common ALL
        DEPENDS 
            hello-world
            dhrystone
            coremark
    )
endif()

# Print build instructions
message(STATUS "")
message(STATUS "Build instructions:")
message(STATUS "  Build all targets:           cmake -DBUILD_ALL=ON ..")
message(STATUS "  Build specific target:       cmake -DBUILD_HELLO_WORLD=ON -DBUILD_DHRYSTONE=OFF -DBUILD_COREMARK=OFF ..")
message(STATUS "  Configure board:             cmake -DBOARD=iss ..")
message(STATUS "  Configure ISA:               cmake -DISA=rv32imc ..")
message(STATUS "  Configure ABI:               cmake -DRISCV_ABI=ilp32 ..")
message(STATUS "  Enable semihosting:          cmake -DSEMIHOSTING=ON ..")
message(STATUS "  Set toolchain path:          cmake -DRISCV_TOOLCHAIN_PATH=/path/to/toolchain ..")
message(STATUS "  Set specific compiler:       cmake -DRISCV_GCC=/path/to/riscv-gcc -DRISCV_GXX=/path/to/riscv-g++ ..")