function build_platform(width, depth)
  for i=0, width-1 do
    for j=0, depth-1 do
      turtle.placeDown()
      turtle.forward()
    end
    for j=0, depth-1 do
      turtle.back()
    end
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
  end
  turtle.turnLeft()
  for i=0, width-1 do
    turtle.forward()
  end
end

build_platform(8, 8)