def __cpu_arch(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-arm8'
        elif hpccm.config.g_cpu_arch == cpu_arch.PPC64LE:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-linux-ppc64le'
        elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-linux-x86_64'
        else: # pragma: no cover
            raise RuntimeError('Unknown CPU architecture')
Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults.
hpccm/building_blocks/charm.py