esptool.py 文件源码

def load_common_header(self, load_file, expected_magic):
            (magic, segments, self.flash_mode, self.flash_size_freq, self.entrypoint) = struct.unpack('<BBBBI', load_file.read(8))

            if magic != expected_magic or segments > 16:
                raise FatalError('Invalid firmware image magic=%d segments=%d' % (magic, segments))
            return segments