code: function fillStub(matrix) {
      var N = matrix.length;
      for (var i = 0; i < 8; i++) {
          if (i != 6) {
              matrix[8][i] = matrix[i][8] = 0x80;
          }
          matrix[8][N - 1 - i] = 0x80;
          matrix[N - 1 - i][8] = 0x80;
      }
      matrix[8][8] = 0x80;
      matrix[N - 8][8] = 0x81;
  
      if (N < 45) return;
  
      for (var i = N - 11; i < N - 8; i++) {
          for (var j = 0; j < 6; j++) {
              matrix[i][j] = matrix[j][i] = 0x80;
          }
      }
  }
docs: {{{1 Fill reserved areas with zeroes