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         True if order adjusted, False otherwise
 108     """
 109     first_refind_number = i = -1
 110     changed_order = False
 111     found_first_refind = ""
 112     show_multiple_warning = True
 113     for entry in boot_order:
 114         i += 1
 115         if label.lower() in boot_entries[entry].lower():
 116             if found_first_refind:
 117                 if show_multiple_warning:
 118                     print("Found multiple {} entries! The earliest in the boot order will be made".format(label))
 119                     print("the default, but this may not be what you want. Manually checking with")
 120                     print("efibootmgr is advisable!\n")
 121                     show_multiple_warning = False
 122             else:
 123                 found_first_refind = entry
 124                 first_refind_number = i
 125     if first_refind_number == -1:
 126         if add_unordered_entry(boot_entries, boot_order, label):
 127             changed_order = True
 128         else:
 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     elif first_refind_number == 0:
 133         print("{} is already the first entry".format(label))
 134     elif first_refind_number > 0:
 135         del boot_order[first_refind_number]
 136         boot_order.insert(0, found_first_refind)
 137         changed_order = True
 138
 139         print("{} is not the first boot entry; adjusting....".format(label))
 140     return changed_order
 141
 142
 143 def save_changes(boot_order):
 144     """Save an altered boot_order.
 145
 146     :param boot_order:
 147         List of boot numbers as strings, in boot order
 148     :returns:
 149         True if there were no problems, False otherwise
 150     """
 151     order_string = ",".join(boot_order)
 152     command = "efibootmgr -o {}".format(order_string)
 153     print("Setting a boot order of {}".format(order_string))
 154     try:
 155         Popen(shlex.split(command), stdout=PIPE).communicate()[0]
 156     except:
 157         print("An error occurred setting the new boot order!")
 158
 159
 160 def main():
 161     """Set rEFInd as the default boot option."""
 162     description = "Sets rEFInd as the default EFI boot option"
 163     parser = ArgumentParser(description=description)
 164     parser.add_argument("-L", "--label",
 165                         default="rEFInd",
 166                         help=("The label used to identify rEFInd (default=rEFInd)"))
 167     args = parser.parse_args()
 168
 169     if sys.platform != "linux":
 170         print("This program is useful only under Linux; exiting!")
 171         return(1)
 172     if shutil.which("efibootmgr") is None:
 173         print("The efibootmgr utility is not installed; exiting!")
 174         return(1)
 175     if not os.geteuid() == 0:
 176         print("This program must be run as root (or via sudo); exiting!")
 177         return(1)
 178
 179     problems = False
 180     retval = 0
 181     boot_entries, boot_order = discover_data()
 182     if boot_entries == {}:
 183         problems = True
 184         print("No EFI boot entries are available. This may indicate a firmware problem.")
 185     if boot_order == []:
 186         problems = True
 187         print("The EFI BootOrder variable is not available. This may indicate a firmware")
 188         print("problem.")
 189     if (not problems and
 190             set_refind_first(boot_entries, boot_order, args.label)):
 191         save_changes(boot_order)
 192     else:
 193         if problems:
 194             retval = 1
 195         print("No changes saved.")
 196     return(retval)
 197
 198 if __name__ == '__main__':
 199     sys.exit(main())