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 shlex
  27 import shutil
  28 import sys
  29
  30 from subprocess import Popen, PIPE
  31 from argparse import ArgumentParser
  32
  33
  34 def discover_data():
  35     """Extract boot entry and boot order information.
  36
  37     :returns:
  38         boot_entries, boot_order
  39     """
  40     command = "efibootmgr -v"
  41     bootinfo_bytes = (Popen(shlex.split(command), stdout=PIPE)
  42                       .communicate()[0])
  43     bootinfo = (bootinfo_bytes.decode(encoding="utf-8", errors="ignore")
  44                 .splitlines())
  45     boot_entries = {}
  46     boot_order = []
  47     if len(bootinfo) > 1:
  48         for s in bootinfo:
  49             if "BootOrder" in s:
  50                 try:
  51                     boot_order = s.split(":")[1].replace(" ", "").split(",")
  52                 except IndexError:
  53                     pass
  54             else:
  55                 # On Boot#### lines, #### is characters 4-8....
  56                 hex_value = s[4:8]
  57                 # ....and the description starts at character 10
  58                 name = s[10:]
  59                 try:
  60                     # In normal efibootmgr output, only Boot#### entries
  61                     # have characters 4-8 that can be interpreted as
  62                     # hex values, so this will harmlessly error out on all
  63                     # but Boot#### entries....
  64                     int(hex_value, 16)
  65                     boot_entries[hex_value] = name
  66                 except ValueError:
  67                     pass
  68     return boot_entries, boot_order
  69
  70
  71 def add_unordered_entry(boot_entries, boot_order, label):
  72     """Find a rEFInd boot_entry and add it to the boot_order list.
  73
  74     Run if the boot_order list includes no rEFInd entry, in the
  75     hopes of finding an existing rEFInd boot_entry that can be
  76     used.
  77     :param boot_entries:
  78         Dictionary of boot entries, with string (hex-encoded number) as
  79         key and description as value
  80     :param boot_order:
  81         List of boot numbers as strings, in boot order
  82     :param label:
  83         String used to identify rEFInd entry in efibootmgr output
  84     :returns:
  85         True if an entry was added, False otherwise
  86     """
  87     added = False
  88     for boot_num, description in boot_entries.items():
  89         if label.lower() in description.lower():
  90             print("Adding Boot{} from boot options list.".format(boot_num))
  91             boot_order.insert(0, boot_num)
  92             added = True
  93     return added
  94
  95
  96 def set_refind_first(boot_entries, boot_order, label):
  97     """Adjust boot_order so that rEFInd is first.
  98
  99     :param boot_entries:
 100         Dictionary of boot entries, with string (hex-encoded number) as
 101         key and description as value
 102     :param boot_order:
 103         List of boot numbers as strings, in boot order
 104     :param label:
 105         String used to identify rEFInd entry in efibootmgr output
 106     :returns:
 107         * -1 if order already OK
 108         * 0 if order adjusted
 109         * 3 if label was not found in available entries
 110     """
 111     first_refind_number = i = -1
 112     retval = 0
 113     found_first_refind = ""
 114     show_multiple_warning = True
 115     for entry in boot_order:
 116         i += 1
 117         if label.lower() in boot_entries[entry].lower():
 118             if found_first_refind:
 119                 if show_multiple_warning:
 120                     print("Found multiple {} entries! The earliest in the boot order will be made".format(label))
 121                     print("the default, but this may not be what you want. Manually checking with")
 122                     print("efibootmgr is advisable!\n")
 123                     show_multiple_warning = False
 124             else:
 125                 found_first_refind = entry
 126                 first_refind_number = i
 127     if first_refind_number == -1:
 128         if not add_unordered_entry(boot_entries, boot_order, label):
 129             print("{} was not found in the boot options list!".format(label))
 130             print("You should create a {} entry with efibootmgr or by re-installing".format(label))
 131             print("(with refind-install, for example)")
 132             retval = 3
 133     elif first_refind_number == 0:
 134         print("{} is already the first entry".format(label))
 135         retval = -1
 136     elif first_refind_number > 0:
 137         del boot_order[first_refind_number]
 138         boot_order.insert(0, found_first_refind)
 139
 140         print("{} is not the first boot entry; adjusting....".format(label))
 141     return retval
 142
 143
 144 def save_changes(boot_order):
 145     """Save an altered boot_order.
 146
 147     :param boot_order:
 148         List of boot numbers as strings, in boot order
 149     :returns:
 150         0 if there were no problems, 1 otherwise
 151     """
 152     retval = 0
 153     order_string = ",".join(boot_order)
 154     command = "efibootmgr -o {}".format(order_string)
 155     print("Setting a boot order of {}".format(order_string))
 156     try:
 157         Popen(shlex.split(command), stdout=PIPE).communicate()[0]
 158     except:
 159         print("An error occurred setting the new boot order!")
 160         retval = 1
 161     return retval
 162
 163
 164 def main():
 165     """Set rEFInd as the default boot option."""
 166     description = "Sets rEFInd as the default EFI boot option"
 167     parser = ArgumentParser(description=description)
 168     parser.add_argument("-L", "--label",
 169                         default="rEFInd",
 170                         help=("The label used to identify rEFInd (default=rEFInd)"))
 171     args = parser.parse_args()
 172
 173     if sys.platform != "linux":
 174         print("This program is useful only under Linux; exiting!")
 175         return(4)
 176     if shutil.which("efibootmgr") is None:
 177         print("The efibootmgr utility is not installed; exiting!")
 178         return(4)
 179     if not os.geteuid() == 0:
 180         print("This program must be run as root (or via sudo); exiting!")
 181         return(4)
 182
 183     retval = 0
 184     boot_entries, boot_order = discover_data()
 185     if boot_entries == {}:
 186         print("No EFI boot entries are available. This may indicate a firmware problem.")
 187         retval = 2
 188     if boot_order == []:
 189         print("The EFI BootOrder variable is not available. This may indicate a firmware")
 190         print("problem.")
 191     if (retval == 0):
 192         changed = set_refind_first(boot_entries, boot_order, args.label)
 193         if (changed == 0):
 194             retval = save_changes(boot_order)
 195         else:
 196             print("No changes saved.")
 197             if changed > 0:
 198                 retval = changed
 199     else:
 200         print("No changes saved.")
 201     return(retval)
 202
 203 if __name__ == '__main__':
 204     sys.exit(main())