docs: def register_image(kwargs=None, call=None):
      '''
      Create an ami from a snapshot
  
      CLI Example:
  
      .. code-block:: bash
  
          salt-cloud -f register_image my-ec2-config ami_name=my_ami description="my description"
                  root_device_name=/dev/xvda snapshot_id=snap-xxxxxxxx
      '''
  
      if call != 'function':
          log.error(
              'The create_volume function must be called with -f or --function.'
          )
          return False
  
      if 'ami_name' not in kwargs:
          log.error('ami_name must be specified to register an image.')
          return False
  
      block_device_mapping = kwargs.get('block_device_mapping', None)
      if not block_device_mapping:
          if 'snapshot_id' not in kwargs:
              log.error('snapshot_id or block_device_mapping must be specified to register an image.')
              return False
          if 'root_device_name' not in kwargs:
              log.error('root_device_name or block_device_mapping must be specified to register an image.')
              return False
          block_device_mapping = [{
              'DeviceName': kwargs['root_device_name'],
              'Ebs': {
                  'VolumeType': kwargs.get('volume_type', 'gp2'),
                  'SnapshotId': kwargs['snapshot_id'],
               }
          }]
  
      if not isinstance(block_device_mapping, list):
          block_device_mapping = [block_device_mapping]
  
      params = {'Action': 'RegisterImage',
                'Name': kwargs['ami_name']}
  
      params.update(_param_from_config('BlockDeviceMapping', block_device_mapping))
  
      if 'root_device_name' in kwargs:
          params['RootDeviceName'] = kwargs['root_device_name']
  
      if 'description' in kwargs:
          params['Description'] = kwargs['description']
  
      if 'virtualization_type' in kwargs:
          params['VirtualizationType'] = kwargs['virtualization_type']
  
      if 'architecture' in kwargs:
          params['Architecture'] = kwargs['architecture']
  
      log.debug(params)
  
      data = aws.query(params,
                       return_url=True,
                       return_root=True,
                       location=get_location(),
                       provider=get_provider(),
                       opts=__opts__,
                       sigver='4')
  
      r_data = {}
      for d in data[0]:
          for k, v in d.items():
              r_data[k] = v
  
      return r_data