docs: def spinn5_local_eth_coord(x, y, w, h, root_x=0, root_y=0):
      """Get the coordinates of a chip's local ethernet connected chip.
  
      Returns the coordinates of the ethernet connected chip on the same board as
      the supplied chip.
  
      .. note::
          This function assumes the system is constructed from SpiNN-5 boards
  
      .. warning::
  
          In general, applications should interrogate the machine to determine
          which Ethernet connected chip is considered 'local' to a particular
          SpiNNaker chip, e.g. using
          :py:class:`rig.machine_control.MachineController.get_system_info`::
  
              >> from rig.machine_control import MachineController
              >> mc = MachineController("my-machine")
              >> si = mc.get_system_info()
              >> print(si[(3, 2)].local_ethernet_chip)
              (0, 0)
  
          :py:func:`.spinn5_local_eth_coord` will always produce the coordinates
          of the Ethernet-connected SpiNNaker chip on the same SpiNN-5 board as
          the supplied chip. In future versions of the low-level system software,
          some other method of choosing local Ethernet connected chips may be
          used.
  
      Parameters
      ----------
      x, y : int
          Chip whose coordinates are of interest.
      w, h : int
          Width and height of the system in chips.
      root_x, root_y : int
          The coordinates of the root chip (i.e. the chip used to boot the
          machine), e.g. from
          :py:attr:`rig.machine_control.MachineController.root_chip`.
      """
      dx, dy = SPINN5_ETH_OFFSET[(y - root_y) % 12][(x - root_x) % 12]
      return ((x + int(dx)) % w), ((y + int(dy)) % h)