iankelling.org Git - automated-distro-installer/blob - chboot

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3
   4 # This program is free software; you can redistribute it and/or
   5 # modify it under the terms of the GNU General Public License
   6 # as published by the Free Software Foundation; either version 2
   7 # of the License, or (at your option) any later version.
   8
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17
  18 # Set grub to boot into a different distro, and reboot unless -r
  19 # $0 [DISTRO_NAME]
  20 # with no argument, print available distros
  21
  22 # DISTRO_NAME is based on the partition names in /boot. eg boot_debianjessie
  23
  24 set -eE -o pipefail
  25 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  26
  27 [[ $EUID == 0 ]] || exec sudo "$BASH_SOURCE" "$@"
  28
  29
  30 ###### begin command line parsing #####
  31 reboot=true
  32 while [[ $1 == -* ]]; do
  33     case $1 in
  34         -d) set -x; shift ;;
  35         -r) reboot=false; shift ;;
  36         --) break ;;
  37     esac
  38 done
  39
  40
  41 distro=$1
  42
  43 if [[ ! $distro ]]; then
  44     echo "available distros:"
  45     btrfs subvolume list /boot | sed -rn 's/^.*boot_(.*)/\1/p'
  46     exit 0
  47 fi
  48
  49 ###### end command line parsing #####
  50
  51
  52 #### begin initial error checking #####
  53
  54 if ! btrfs subvolume list /boot | grep "_$distro$" &>/dev/null; then
  55     echo "$0: error: _$distro$ not found in btrfs subvolume list /boot:"
  56     btrfs subvolume list /boot
  57     exit 1
  58 fi
  59
  60 #### end initial error checking #####
  61
  62 e() { echo "$@"; "$@"; }
  63
  64 boot_dev=$(mount | sed -rn "s#^(\S+) on /boot .*#\1#p")
  65
  66 mount_point=$(mktemp -d)
  67
  68 e mount -o subvol=boot_$distro $boot_dev $mount_point
  69
  70 boot_disk=${boot_dev%%[0-9]*}
  71
  72 # arch doesn't have $mount_point/grub/device.map, accoring to the grub manual,
  73 # it just generates one if the file doesn't exist.
  74 # https://www.gnu.org/software/grub/manual/html_node/Device-map.html
  75 e grub-bios-setup -d $mount_point/grub/i386-pc -s -m $mount_point/grub/device.map $boot_disk
  76
  77 e umount $mount_point
  78 e rmdir $mount_point
  79
  80 if $reboot; then
  81     touch /tmp/keyscript-off
  82     reboot now
  83 fi