cmake_minimum_required(VERSION 3.22)

# must be set before project()
set(CMAKE_TOOLCHAIN_FILE "${CMAKE_SOURCE_DIR}/cmake/arm-none-eabi.cmake")

project(ptt_fhss C ASM)

set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED ON)

# sources
add_executable(firmware
    src/startup.c
    src/main.c
    src/radio.c
    src/fhss.c
    src/power.c
    vendor/tiny-aes-c/aes.c
)

# include paths
target_include_directories(firmware PRIVATE
    include
    vendor/nrfx/mdk                    # nRF52840 device headers (nrf52840.h etc.)
    vendor/CMSIS_5/CMSIS/Core/Include  # core_cm4.h, cmsis_gcc.h etc.
    vendor/tiny-aes-c
)

# preprocessor defines
target_compile_definitions(firmware PRIVATE
    NRF52840_XXAA  # device variant required by nrfx/mdk headers
)

# compiler flags
set(CPU_FLAGS
    -mcpu=cortex-m4
    -mthumb
    -mfpu=fpv4-sp-d16
    -mfloat-abi=hard
)

target_compile_options(firmware PRIVATE
    ${CPU_FLAGS}
    -Os
    -ffunction-sections
    -fdata-sections
    -fno-exceptions
    -Wall
    -Wextra
    -Werror
)

# linker
target_link_options(firmware PRIVATE
    ${CPU_FLAGS}
    -T ${CMAKE_SOURCE_DIR}/link/nrf52840.ld
    -Wl,--gc-sections
    -Wl,--print-memory-usage
    -Wl,-Map=${CMAKE_BINARY_DIR}/firmware.map
    -nostartfiles
    -specs=nano.specs
    -specs=nosys.specs
)

# post-build: .hex + size report
add_custom_command(TARGET firmware POST_BUILD
    COMMAND arm-none-eabi-objcopy
            -O ihex $<TARGET_FILE:firmware>
            ${CMAKE_BINARY_DIR}/firmware.hex
    COMMAND arm-none-eabi-size $<TARGET_FILE:firmware>
    VERBATIM
)