docs: def wrap_stub(elf_file):
      """ Wrap an ELF file into a stub 'dict' """
      print('Wrapping ELF file %s...' % elf_file)
      e = esptool.ELFFile(elf_file)
  
      text_section = e.get_section('.text')
      try:
          data_section = e.get_section('.data')
      except ValueError:
          data_section = None
      stub = {
           'text': text_section.data,
           'text_start': text_section.addr,
           'entry': e.entrypoint,
          }
      if data_section is not None:
          stub['data'] = data_section.data
          stub['data_start'] = data_section.addr
  
      # Pad text with NOPs to mod 4.
      if len(stub['text']) % 4 != 0:
          stub['text'] += (4 - (len(stub['text']) % 4)) * '\0'
  
      print('Stub text: %d @ 0x%08x, data: %d @ 0x%08x, entry @ 0x%x' % (
          len(stub['text']), stub['text_start'],
          len(stub.get('data', '')), stub.get('data_start', 0),
          stub['entry']), file=sys.stderr)
      return stub