Additional data for macOS systems
    Returns: A dictionary containing values for the following:
        - model_name
        - boot_rom_version
        - smc_version
        - system_serialnumber

def _osx_platform_data():
    '''
    Additional data for macOS systems
    Returns: A dictionary containing values for the following:
        - model_name
        - boot_rom_version
        - smc_version
        - system_serialnumber
    '''
    cmd = 'system_profiler SPHardwareDataType'
    hardware = __salt__['cmd.run'](cmd)

    grains = {}
    for line in hardware.splitlines():
        field_name, _, field_val = line.partition(': ')
        if field_name.strip() == "Model Name":
            key = 'model_name'
            grains[key] = _clean_value(key, field_val)
        if field_name.strip() == "Boot ROM Version":
            key = 'boot_rom_version'
            grains[key] = _clean_value(key, field_val)
        if field_name.strip() == "SMC Version (system)":
            key = 'smc_version'
            grains[key] = _clean_value(key, field_val)
        if field_name.strip() == "Serial Number (system)":
            key = 'system_serialnumber'
            grains[key] = _clean_value(key, field_val)

    return grains