yastfli

#!/usr/bin/env bash
# SPDX-License-Identifier: GPL-3.0-or-later
# Copyright (C) 2024-2025, Manuel Fombuena <mfombuena@innovara.co.uk>
#
# yastfli -  Yet Another Script To Flash LiveOS ISOs
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#

export PATH=/sbin:/usr/sbin:$PATH

### HELP STARTS ###
usage() {
  echo "
 SYNTAX

 (sudo) yastfli [options] --iso <path> --target <device>

 OPTIONS

 --directory|-d
   Use a directory overlay instead of an image file.
   It can't be used with fat32. Size option would be ignored.
   Default is false.

 --filesystem|-f [ext4|fat32]
   Filesystem of the data partition.
   Default is ext4.

 --iso|-i
   Path to Live ISO file.

 --label|-l
   Label of the data partition.
   Default is LIVE.

 --no-overlay|-n
   Don't create an overlay.
   Default is false.

 --preserve|-p
   Don't format EFI and data partitions.
   Delete EFI, images and LiveOS folders instead. Deletes overlay.
   Default is false.

 --size-mb|-s
   Size in MB of the overlay file.
   It can't be more than 4095 for fat32 data partitions.
   Default is 512.

 --target|-t
   Target device e.g. /dev/sda.

 --help|-h
   This help.
 "
  exit 1
}
### HELP ENDS ###

### root CHECK STARTS ###
if [[ $(id -u) -ne 0 ]]; then
   echo "ERROR: yastfli must be run as root"
   exit 1
fi
### root CHECK ENDS ###

### VARIABLE INITIALIZATION STARTS ###
datafs='ext4'
dirovl=false
iso=''
label='LIVE'
nofmt=false
noovl=false
size=512
tgt=''
green='\033[0;32m'
nc='\033[0m' # no color
### VARIABLE INITIALIZATION ENDS ###

### ARGUMENT PROCESSING STARTS ###
while true ; do
  case $1 in
    --help|-h)
      usage
      ;;
    --directory|-d)
      dirovl=true
      shift 0
      ;;
    --filesystem|-f)
      datafs="${2}"
      shift
      ;;
    --iso|-i)
      iso="${2}"
      shift
      ;;
    --label|-l)
      label="${2}"
      shift
      ;;
    --no-overlay|-n)
      noovl=true
      shift 0
      ;;
    --preserve|-p)
      nofmt=true
      shift 0
      ;;
    --size-mb|-s)
      size="${2}"
      shift
      ;;
    --target|-t)
      tgt="${2}"
      shift
      ;;
    --*|-*)
      echo "ERROR: invalid syntax. Use -h for help"
      exit 1
      ;;
    *)
      break
  esac
  shift
done
### ARGUMENT PROCESSING ENDS ###

### ARGUMENT HANDLING STARTS ###
[[ "${tgt}" = *?[0-9] ]] && tgtp1="${tgt}"p1 || tgtp1="${tgt}"1 # e.g. /dev/mmcblk0p1 || /dev/sda1
[[ "${tgt}" = *?[0-9] ]] && tgtp2="${tgt}"p2 || tgtp2="${tgt}"2 # e.g. /dev/mmcblk0p2 || /dev/sda2
[[ -n "${tgt}" && -n $(parted -s "${tgtp1}" print 2>/dev/null | grep fat32) ]] && tgtp1fs="fat32"
[[ -n "${tgt}" && -n $(parted -s "${tgtp2}" print 2>/dev/null | grep ext4) ]] && tgtp2fs="ext4"
[[ -n "${tgt}" && -n $(parted -s "${tgtp2}" print 2>/dev/null | grep fat32) ]] && tgtp2fs="fat32"
if [[ -z "${iso}" || -z "${tgt}" ]]; then
  echo "ERROR: invalid syntax. You need at least -i <iso> -t <device>"
  exit 1
elif ! [[ -f "${iso}" ]]; then
  echo "ERROR: ISO file "${iso}" doesn't exist"
  exit 1
elif ! [[ -b "${tgt}" ]]; then
  echo "ERROR: "${tgt}" not present"
  exit 1
elif [[ "${datafs}" != "ext4" && "${datafs}" != "fat32" ]]; then
  echo "ERROR: invalid data partition filesystem "${datafs}". It can only be ext4 or fat32"
  exit 1
elif [[ ${nofmt} == true && \
  (( "${tgtp1fs}" != "fat32" ) || ("${tgtp2fs}" != "ext4" && "${tgtp2fs}" != "fat32" )) ]]; then 
  echo "ERROR: preserve mode can't be used with this device. Was yastfli used to create the Live OS?"
  exit 1
elif [[ ( "${datafs}" == "fat32" || "${tgtp2fs}" == "fat32" ) && \
           ${dirovl} == true && ${noovl} == false ]]; then
  echo "ERROR: directory overlay can't be used with fat32 on "${tgtp2}""
  exit 1
fi
if [[ ${nofmt} == true ]]; then
  echo "INFO:  filesystem on "${tgtp2}" is "${tgtp2fs}"."
  datafs="${tgtp2fs}"
fi
if [[ "${datafs}" == "fat32" && ${size} -gt 4095 && ${noovl} == false ]]; then
  echo "INFO:  fat32 can't hold an overlay of "${size}"M. Reduced to 4095M"
  size=4095
elif [[ ${noovl} == true ]]; then
  echo "INFO:  overlay set no. Any overlay options will be ignored"
fi
### ARGUMENT HANDLING ENDS ###

### DEVICE PREP STARTS ###
ls "${tgt}"* | xargs -n1 umount -l >/dev/null 2>&1
isoloop=$(losetup -Pf "${iso}" --show)
isodata=$(mktemp -d)
mount "${isoloop}" "${isodata}" >/dev/null 2>&1
### DEVICE PREP ENDS ###

### EFI PARTITION STARTS ###
if [[ ${nofmt} != true ]]; then # format on normal mode
  echo -e "${green}[1/7]${nc}  formatting EFI partition"
  parted -s "${tgt}" mklabel gpt
  parted -s "${tgt}" mkpart '"EFI System Partition"' fat32 1MiB 257MiB
  parted -s "${tgt}" set 1 esp on
  mkfs.fat -n ESP -F32 "${tgtp1}" &> /dev/null
  fsck.fat -aVw "${tgtp1}" &> /dev/null
fi
espmnt=$(mktemp -d)
mount "${tgtp1}" "${espmnt}"
if [[ ${nofmt} == true ]]; then # delete folders on preserve mode
  echo -e "${green}[1/7]${nc}  preserving EFI partition. Deleting EFI and images folders"
  rm -fr "${espmnt}"/{"EFI","images"}
  sync -f "${espmnt}"/
fi
echo -e "${green}[2/7]${nc}  copying data to EFI partition"
rsync -a --progress "${isodata}"/{"EFI","images"} "${espmnt}"/
echo "INFO:  syncing filesystem writes to disk. Please wait"
sync -f "${espmnt}"/
### EFI PARTITION ENDS ###

### DATA PARTITION STARTS ###
if [[ ${nofmt} != true ]]; then # format on normal mode
  echo -e "${green}[3/7]${nc}  formatting "${label}" partition"
  parted -s "${tgt}" mkpart '"Main Data Partition"' "${datafs}" 257MiB 100%
  case "${datafs}" in
    ext4)
      mkfs.ext4 -F -L "${label}" -O ^64bit -j "${tgtp2}" &> /dev/null
      tune2fs -c0 -i0 -ouser_xattr,acl "${tgtp2}" &> /dev/null
      e2fsck -yf "${tgtp2}" &> /dev/null
      ;;
    fat32)
      mkfs.fat -n "${label}" -F32 "${tgtp2}" &> /dev/null
      fsck.fat -aVw "${tgtp2}" &> /dev/null
      ;;
    *)
      echo "ERROR: invalid "${label}" file system "${datafs}". It can only be ext4 or fat32"
      exit 1
      ;;
  esac
fi
datamnt=$(mktemp -d)
mount "${tgtp2}" "${datamnt}"
if [[ ${nofmt} == true ]]; then # delete folders on preserve mode
  echo -e "${green}[3/7]${nc}  preserving "${label}" partition. Deleting LiveOS folder"
  rm -fr "${datamnt}"/LiveOS
  sync -f "${datamnt}"/
fi
echo -e "${green}[4/7]${nc}  copying data to "${label}" partition"
rsync -a --progress --exclude={"EFI","images","boot"} "${isodata}/" "${datamnt}"
echo "INFO:  syncing filesystem writes to disk. This may take a while..."
sync -f "${datamnt}"/
### DATA PARTITION ENDS ###

### OVERLAY STARTS ###
tgtuuid=($(lsblk -no UUID "${tgtp2}" || :)) # out of if statement because it's always needed
if [[ ${noovl} != true ]]; then # create on normal mode
  tgtlabel=($(lsblk -no LABEL "${tgtp2}" || :))
  tgtfile=overlay-"${tgtlabel}"-"${tgtuuid}"
  ovlpath="${datamnt}"/LiveOS/"${tgtfile}"
  echo -e "${green}[5/7]${nc}  initializing persistent overlay LiveOS/"${tgtfile}" on "${tgtp2}""
  if [[ ${dirovl} == true && "${datafs}" == "ext4" ]]; then
    mkdir -m 0755 --context=system_u:object_r:root_t:s0 $datamnt/LiveOS/overlayfs $datamnt/LiveOS/ovlwork
  else
    truncate -s 0 "${ovlpath}"
    [[ "${datafs}" == "fat32" ]] && \
      echo "INFO:  allocating disk space for overlay file. This may take a while"
    fallocate -x -l ${size}M "${ovlpath}"
    [[ "${datafs}" == "fat32" ]] && \
      echo "INFO:  syncing filesystem writes to disk"
    sync -f "${ovlpath}"
    mkfs.ext4 -F -L OVERLAY -O ^64bit -j -E nodiscard "${ovlpath}" &> /dev/null
    tune2fs -c0 -i0 -ouser_xattr,acl "${ovlpath}" &> /dev/null
    e2fsck -yf "${ovlpath}" &> /dev/null
    ovl=$(mktemp -d)
    mount "${ovlpath}" "${ovl}"
    mkdir -m 0755 --context=system_u:object_r:root_t:s0 $ovl/overlayfs $ovl/ovlwork
    umount $ovl
    chmod 0600 "${ovlpath}" &> /dev/null || :
  fi
else
  echo -e "${green}[5/7]${nc}  skipping persistent overlay initialization"
fi
### OVERLAY ENDS ###

### GRUB STARTS ###
echo -e "${green}[6/7]${nc}  updating EFI/BOOT/grub.cfg on "${tgtp1}""
isolabel=($(lsblk -no LABEL "${isoloop}" || :))
sed -i -r "s/root=live:CDLABEL="${isolabel}"/root=live:UUID="${tgtuuid}"/" "${espmnt}"/EFI/BOOT/grub.cfg
sed -i -r "s/set default=\"1\"/set default=\"0\"/" "${espmnt}"/EFI/BOOT/grub.cfg
if [[ ${noovl} != true ]]; then # update on normal mode
  if [[ ${dirovl} == true && "${datafs}" == "ext4" ]]; then
    sed -i -r "s/rd\.live\.image|liveimg/& rd.live.overlay=UUID="${tgtuuid}":\/LiveOS\/overlayfs rd.live.overlay.overlayfs/" "${espmnt}"/EFI/BOOT/grub.cfg
  else
    sed -i -r "s/rd\.live\.image|liveimg/& rd.live.overlay=UUID="${tgtuuid}" rd.live.overlay.overlayfs/" "${espmnt}"/EFI/BOOT/grub.cfg
  fi
fi
### GRUB ENDS ###

### CLEAN UP STARTS ###
echo -e "${green}[7/7]${nc}  cleaning up"
umount "${isoloop}"
losetup -d "${isoloop}"
umount "${espmnt}"
umount "${datamnt}"
eject "${tgt}"
udisksctl power-off -b "${tgt}"
echo "INFO:  finished. You can unplug your device now"
### CLEAN UP ENDS ###