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
  19 set -eE -o pipefail
  20 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  21
  22 [[ $EUID == 0 ]] || exec sudo "$BASH_SOURCE" "$@"
  23
  24 usage() {
  25     cat <<EOF
  26 Usage: ${0##*/} [OPTIONS] DISTRO_NAME
  27 Set grub to boot into a different distro, and reboot unless -r
  28
  29 With no argument, print available distros
  30 DISTRO_NAME is based on the partition names in /boot.
  31 For example debianjessie for the partitionn boot_debianjessie.
  32
  33 -r         Do not reboot.
  34 -d         Enable debug output.
  35 -h|--help  Print help and exit.
  36
  37 Note: Uses GNU getopt options parsing style
  38 EOF
  39     exit $1
  40 }
  41
  42
  43 grub_extn=4
  44
  45 ###### begin command line parsing #####
  46 reboot=true
  47 temp=$(getopt -l help hdr "$@") || usage 1
  48 eval set -- "$temp"
  49 while true; do
  50     case $1 in
  51         -d) set -x; shift ;;
  52         -r) reboot=false; shift ;;
  53         -h|--help) usage ;;
  54         --) shift; break ;;
  55         *) echo "$0: Internal error!" ; exit 1 ;;
  56     esac
  57 done
  58
  59
  60 distro=$1
  61
  62 if [[ ! $distro ]]; then
  63     echo "available distros:"
  64     cur=$(btrfs subvol show /boot| sed -rn 's/^.*Name:\s*(\S*).*/\1/p')
  65     btrfs subvolume list /boot | awk '{print $9}' | sed "s/$cur/$cur (current)/"
  66     exit 0
  67 fi
  68
  69 ###### end command line parsing #####
  70
  71
  72 #### begin initial error checking #####
  73
  74 if ! btrfs subvolume list /boot | grep "_$distro$" &>/dev/null; then
  75     echo "$0: error: _$distro$ not found in btrfs subvolume list /boot:"
  76     btrfs subvolume list /boot
  77     exit 1
  78 fi
  79
  80 #### end initial error checking #####
  81
  82 e() { echo "$@"; "$@"; }
  83
  84 boot_dev=$(mount | sed -rn "s#^(\S+) on /boot .*#\1#p")
  85
  86 mount_point=$(mktemp -d)
  87
  88 e mount -o subvol=boot_$distro $boot_dev $mount_point
  89
  90 boot_disk=${boot_dev%%[0-9]*}
  91
  92 # arch doesn't have $mount_point/grub/device.map, accoring to the grub manual,
  93 # it just generates one if the file doesn't exist.
  94 # https://www.gnu.org/software/grub/manual/html_node/Device-map.html
  95 e grub-bios-setup -d $mount_point/grub/i386-pc -s -m $mount_point/grub/device.map $boot_disk
  96
  97 # todo, mount_point needs subvolid=0
  98
  99 e umount $mount_point
 100
 101 e mount $boot_disk$grub_extn $mount_point
 102 e grub-editenv $mount_point/grubenv set last_boot=/boot_$distro
 103 e grub-editenv $mount_point/grubenv set did_fai_check=true
 104 e umount $mount_point
 105 e rmdir $mount_point
 106
 107 if $reboot; then
 108     touch /tmp/keyscript-off
 109     reboot now
 110 fi