code.delx.au - refind/blob - refind-mkdefault

   1 #!/usr/bin/env python3
   2
   3 """
   4 Set rEFInd as the default boot loader, using Linux's efibootmgr tool.
   5
   6 Copyright (c) 2016 Roderick W. Smith
   7
   8 Authors:
   9   Roderick W. Smith <rodsmith@rodsbooks.com>
  10
  11 This program is free software: you can redistribute it and/or modify
  12 it under the terms of the GNU General Public License version 3, or
  13 (at your option) any later version, as published by the Free Software
  14 Foundation.
  15
  16 This program is distributed in the hope that it will be useful,
  17 but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 GNU General Public License for more details.
  20
  21 You should have received a copy of the GNU General Public License
  22 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 """
  24
  25 import os
  26 import shutil
  27 import sys
  28
  29 from subprocess import Popen, PIPE
  30 from argparse import ArgumentParser
  31
  32
  33 def discover_data():
  34     """Extract boot entry and boot order information.
  35
  36     :returns:
  37         boot_entries, boot_order
  38     """
  39     command = "efibootmgr -v"
  40     bootinfo_bytes = (Popen(command, stdout=PIPE, shell=True)
  41                       .communicate()[0])
  42     bootinfo = (bootinfo_bytes.decode(encoding="utf-8", errors="ignore")
  43                 .splitlines())
  44     boot_entries = {}
  45     boot_order = []
  46     if len(bootinfo) > 1:
  47         for s in bootinfo:
  48             if "BootOrder" in s:
  49                 try:
  50                     boot_order = s.split(":")[1].replace(" ", "").split(",")
  51                 except IndexError:
  52                     pass
  53             else:
  54                 # On Boot#### lines, #### is characters 4-8....
  55                 hex_value = s[4:8]
  56                 # ....and the description starts at character 10
  57                 name = s[10:]
  58                 try:
  59                     # In normal efibootmgr output, only Boot#### entries
  60                     # have characters 4-8 that can be interpreted as
  61                     # hex values, so this will harmlessly error out on all
  62                     # but Boot#### entries....
  63                     int(hex_value, 16)
  64                     boot_entries[hex_value] = name
  65                 except ValueError:
  66                     pass
  67     return boot_entries, boot_order
  68
  69
  70 def add_unordered_entry(boot_entries, boot_order, label):
  71     """Find a rEFInd boot_entry and add it to the boot_order list.
  72
  73     Run if the boot_order list includes no rEFInd entry, in the
  74     hopes of finding an existing rEFInd boot_entry that can be
  75     used.
  76     :param boot_entries:
  77         Dictionary of boot entries, with string (hex-encoded number) as
  78         key and description as value
  79     :param boot_order:
  80         List of boot numbers as strings, in boot order
  81     :param label:
  82         String used to identify rEFInd entry in efibootmgr output
  83     :returns:
  84         True if an entry was added, False otherwise
  85     """
  86     added = False
  87     for boot_num, description in boot_entries.items():
  88         if label.lower() in description.lower():
  89             print("Adding Boot{} from boot options list.".format(boot_num))
  90             boot_order.insert(0, boot_num)
  91             added = True
  92     return added
  93
  94
  95 def set_refind_first(boot_entries, boot_order, label):
  96     """Adjust boot_order so that rEFInd is first.
  97
  98     :param boot_entries:
  99         Dictionary of boot entries, with string (hex-encoded number) as
 100         key and description as value
 101     :param boot_order:
 102         List of boot numbers as strings, in boot order
 103     :param label:
 104         String used to identify rEFInd entry in efibootmgr output
 105     :returns:
 106         True if order adjusted, False otherwise
 107     """
 108     first_refind_number = i = -1
 109     changed_order = False
 110     found_first_refind = ""
 111     show_multiple_warning = True
 112     for entry in boot_order:
 113         i += 1
 114         if label.lower() in boot_entries[entry].lower():
 115             if found_first_refind:
 116                 if show_multiple_warning:
 117                     print("Found multiple {} entries! The earliest in the boot order will be made".format(label))
 118                     print("the default, but this may not be what you want. Manually checking with")
 119                     print("efibootmgr is advisable!\n")
 120                     show_multiple_warning = False
 121             else:
 122                 found_first_refind = entry
 123                 first_refind_number = i
 124     if first_refind_number == -1:
 125         if add_unordered_entry(boot_entries, boot_order, label):
 126             changed_order = True
 127         else:
 128             print("{} was not found in the boot options list!".format(label))
 129             print("You should create a {} entry with efibootmgr or by re-installing".format(label))
 130             print("(with refind-install, for example)")
 131     elif first_refind_number == 0:
 132         print("{} is already the first entry".format(label))
 133     elif first_refind_number > 0:
 134         del boot_order[first_refind_number]
 135         boot_order.insert(0, found_first_refind)
 136         changed_order = True
 137
 138         print("{} is not the first boot entry; adjusting....".format(label))
 139     return changed_order
 140
 141
 142 def save_changes(boot_order):
 143     """Save an altered boot_order.
 144
 145     :returns:
 146         True if there were no problems, False otherwise
 147     """
 148     order_string = ",".join(boot_order)
 149     command = "efibootmgr -o {}".format(order_string)
 150     print("Setting a boot order of {}".format(order_string))
 151     try:
 152         Popen(command, stdout=PIPE, shell=True).communicate()[0]
 153     except:
 154         print("An error occurred setting the new boot order!")
 155
 156
 157 def main():
 158     """Set rEFInd as the default boot option."""
 159     description = "Sets rEFInd as the default EFI boot option"
 160     parser = ArgumentParser(description=description)
 161     parser.add_argument("-L", "--label",
 162                         default="rEFInd",
 163                         help=("The label used to identify rEFInd"))
 164     args = parser.parse_args()
 165
 166     if sys.platform != "linux":
 167         print("This program is useful only under Linux; exiting!")
 168         return(1)
 169     if shutil.which("efibootmgr") is None:
 170         print("The efibootmgr utility is not installed; exiting!")
 171         return(1)
 172     if not os.geteuid() == 0:
 173         print("You must be root to run this program")
 174         return(1)
 175
 176     problems = False
 177     retval = 0
 178     boot_entries, boot_order = discover_data()
 179     if boot_entries == {}:
 180         problems = True
 181         print("No EFI boot entries available. This may indicate a firmware problem.")
 182     if boot_order == []:
 183         problems = True
 184         print("The EFI BootOrder variable is not available. This may indicate a firmware")
 185         print("problem.")
 186     if (boot_entries != {} and boot_order != [] and
 187             set_refind_first(boot_entries, boot_order, args.label)):
 188         save_changes(boot_order)
 189     else:
 190         if problems:
 191             retval = 1
 192         print("No changes saved.")
 193     return(retval)
 194
 195 if __name__ == '__main__':
 196     sys.exit(main())