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 $?"' ERR
  11
  12 [[ $EUID == 0 ]] || exec sudo "$BASH_SOURCE" "$@"
  13
  14 reboot=true
  15 while [[ $1 == -* ]]; do
  16     case $1 in
  17         -d) set -x; shift ;;
  18         -r) reboot=false; shift ;;
  19         --) break ;;
  20     esac
  21 done
  22
  23
  24 distro=$1
  25
  26 ###### end command line parsing #####
  27
  28 if [[ ! $distro ]]; then
  29     echo "available distros:"
  30     btrfs subvolume list /boot | sed -rn 's/^.*boot_(.*)/\1/p'
  31     exit 0
  32 fi
  33
  34 if ! btrfs subvolume list /boot | grep "_$distro$" &>/dev/null; then
  35     echo "$0: error: _$distro$ not found in btrfs subvolume list /boot:"
  36     btrfs subvolume list /boot
  37     exit 1
  38 fi
  39
  40 e() { echo "$@"; "$@"; }
  41
  42 boot_dev=$(mount | sed -rn "s#^(\S+) on /boot .*#\1#p")
  43
  44 mount_point=$(mktemp -d)
  45
  46 e mount -o subvol=boot_$distro $boot_dev $mount_point
  47
  48 boot_disk=${boot_dev%%[0-9]*}
  49
  50 # arch doesn't have $mount_point/grub/device.map, accoring to the grub manual,
  51 # it just generates one if the file doesn't exist.
  52 # https://www.gnu.org/software/grub/manual/html_node/Device-map.html
  53 e grub-bios-setup -d $mount_point/grub/i386-pc -s -m $mount_point/grub/device.map $boot_disk
  54
  55 e umount $mount_point
  56 e rmdir $mount_point
  57
  58 if $reboot; then
  59     reboot now
  60 fi