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

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