old_contents: import uos
  import network
  from flashbdev import bdev
  
  def wifi():
      import ubinascii
      ap_if = network.WLAN(network.AP_IF)
      ap_if.config(essid=b"MicroPython %s" % ubinascii.hexlify(ap_if.mac()[-3:]))
  
  def check_bootsec():
      buf = bytearray(bdev.SEC_SIZE)
      bdev.readblocks(0, buf)
      empty = True
      for b in buf:
          if b != 0xff:
              empty = False
              break
      if empty:
          return True
      fs_corrupted()
  
  def fs_corrupted():
      import time
      while 1:
          print("""\
  FAT filesystem appears to be corrupted. If you had important data there, you
  may want to make a flash snapshot to try to recover it. Otherwise, perform
  factory reprogramming of MicroPython firmware (completely erase flash, followed
  by firmware programming).
  """)
          time.sleep(3)
  
new_contents: import uos
  import network
  from flashbdev import bdev
  
  def wifi():
      import ubinascii
      ap_if = network.WLAN(network.AP_IF)
      essid = b"MicroPython %s" % ubinascii.hexlify(ap_if.mac()[-3:])
      ap_if.config(essid=essid, authmode=network.AUTH_WPA_WPA2_PSK, password=b"micropythoN")
  
  def check_bootsec():
      buf = bytearray(bdev.SEC_SIZE)
      bdev.readblocks(0, buf)
      empty = True
      for b in buf:
          if b != 0xff:
              empty = False
              break
      if empty:
          return True
      fs_corrupted()
  
  def fs_corrupted():
      import time
      while 1:
          print("""\
  FAT filesystem appears to be corrupted. If you had important data there, you
  may want to make a flash snapshot to try to recover it. Otherwise, perform
  factory reprogramming of MicroPython firmware (completely erase flash, followed
  by firmware programming).
  """)
          time.sleep(3)
  
subject: Set WPA/WPA2 AP mode with a predefined password.