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

   1 #!/bin/bash
   2
   3 # Set grub to boot into a different distro, and reboot unless -r
   4 # $0 [DISTRO_NAME]
   5 # with no argument, print available distros
   6
   7 # DISTRO_NAME is based on the partition names in /boot. eg boot_debianjessie
   8
   9 set -eE -o pipefail
  10 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  11
  12 [[ $EUID == 0 ]] || exec sudo "$BASH_SOURCE" "$@"
  13
  14
  15 ###### begin command line parsing #####
  16 reboot=true
  17 while [[ $1 == -* ]]; do
  18     case $1 in
  19         -d) set -x; shift ;;
  20         -r) reboot=false; shift ;;
  21         --) break ;;
  22     esac
  23 done
  24
  25
  26 distro=$1
  27
  28 if [[ ! $distro ]]; then
  29     echo "available distros:"
  30     btrfs subvolume list /boot | sed -rn 's/^.*boot_(.*)/\1/p'
  31     exit 0
  32 fi
  33
  34 ###### end command line parsing #####
  35
  36
  37 #### begin initial error checking #####
  38
  39 if ! btrfs subvolume list /boot | grep "_$distro$" &>/dev/null; then
  40     echo "$0: error: _$distro$ not found in btrfs subvolume list /boot:"
  41     btrfs subvolume list /boot
  42     exit 1
  43 fi
  44
  45 #### end initial error checking #####
  46
  47 e() { echo "$@"; "$@"; }
  48
  49 boot_dev=$(mount | sed -rn "s#^(\S+) on /boot .*#\1#p")
  50
  51 mount_point=$(mktemp -d)
  52
  53 e mount -o subvol=boot_$distro $boot_dev $mount_point
  54
  55 boot_disk=${boot_dev%%[0-9]*}
  56
  57 # arch doesn't have $mount_point/grub/device.map, accoring to the grub manual,
  58 # it just generates one if the file doesn't exist.
  59 # https://www.gnu.org/software/grub/manual/html_node/Device-map.html
  60 e grub-bios-setup -d $mount_point/grub/i386-pc -s -m $mount_point/grub/device.map $boot_disk
  61
  62 e umount $mount_point
  63 e rmdir $mount_point
  64
  65 if $reboot; then
  66     touch /tmp/keyscript-off
  67     reboot now
  68 fi