Updated the hard disk image generation tool to generate proper folder/sparse overlay structure.

src/11_generate_iso.sh

@@ -119,5 +119,12 @@ isohybrid ../minimal_linux_live.iso 2>/dev/null || true
 # Copy the ISO image to the root project folder.
 cp ../minimal_linux_live.iso ../../
 
+if [ "$(id -u)" = "0" ] ; then
+  # Apply ownership back to original owner for all affected files.
+  chown $(logname) ../../minimal_linux_live.iso
+  chown $(logname) ../../work/minimal_linux_live.iso
+  chown -R $(logname) .  
+fi
+
 cd ../..
 

src/generate_hdd.sh

@@ -2,6 +2,114 @@
 
 # Create sparse file of 20MB which can be used by QEMU.
 
+if [ "$1" = "" ] ; then
+  rm -f hdd.img
+  truncate -s 20M hdd.img
+elif [ "$1" = "-f" -o "$1" = "-folder" ] ; then
+  if [ ! "$(id -u)" = "0" ] ; then
+    echo "Using option '-f' (or '-folder') requires root permissions."
+    exit 1
+  fi
+  
+  echo "Create new hard disk image file with 20MB size."
   rm -f hdd.img
   truncate -s 20M hdd.img
   
+  LOOP_DEVICE=$(losetup -f)
+  
+  echo "Attach hard disk image file to loop device."
+  losetup $LOOP_DEVICE hdd.img
+  
+  echo "Format hard disk image file with Ext2 filesystem."
+  mkfs.ext2 $LOOP_DEVICE
+  
+  echo "Mount hard disk image file to temporary folder."
+  mkdir folder
+  mount hdd.img folder
+  
+  echo "Create overlay structure."
+  mkdir -p folder/minimal/rootfs
+  mkdir -p folder/minimal/work
+  
+  echo "Create sample text file."
+  echo "This file is on external hard disk." > folder/minimal/rootfs/overlay.txt 
+
+  echo "Unmount hard disk image file."
+  umount folder
+  rm -rf folder
+  
+  echo "Detach hard disk image file from loop device."
+  losetup -d $LOOP_DEVICE
+  
+  echo "Apply original ownership to hard disk image file."
+  chown $(logname) hdd.img
+elif [ "$1" = "-s" -o "$1" = "-sparse" ] ; then
+  if [ ! "$(id -u)" = "0" ] ; then
+    echo "Using option '-s' (or '-sparse') requires root permissions."
+    exit 1
+  fi
+  
+  echo "Create new hard disk image file with 20MB size."
+  rm -f hdd.img
+  truncate -s 20M hdd.img
+  
+  LOOP_DEVICE_HDD=$(losetup -f)
+  
+  echo "Attach hard disk image file to loop device."
+  losetup $LOOP_DEVICE_HDD hdd.img
+  
+  echo "Format hard disk image file with FAT filesystem."
+  mkfs.vfat $LOOP_DEVICE_HDD
+  
+  echo "Mount hard disk image file to temporary folder."
+  mkdir sparse
+  mount hdd.img sparse
+  
+  echo "Create new overlay image file with 1MB size."
+  rm -f sparse/minimal.img
+  truncate -s 1M sparse/minimal.img
+
+  LOOP_DEVICE_OVL=$(losetup -f)
+  echo "Attach overlay image file to loop device."
+  losetup $LOOP_DEVICE_OVL sparse/minimal.img
+
+  echo "Format overlay image file with Ext2 filesystem."
+  mkfs.ext2 $LOOP_DEVICE_OVL
+
+  echo "Mount overlay image file to temporary folder."
+  mkdir ovl
+  mount sparse/minimal.img ovl
+  
+  echo "Create overlay structure."
+  mkdir -p ovl/rootfs
+  mkdir -p ovl/work
+  
+  echo "Create sample text file."
+  echo "This file is on external hard disk." > ovl/rootfs/overlay.txt
+
+  echo "Apply root ownership to overlay content."
+  chown -R root:root ovl
+
+  echo "Unmount overlay image file."
+  umount ovl
+  sleep 1
+  rm -rf ovl
+
+  echo "Detach overlay image file from loop device."
+  losetup -d $LOOP_DEVICE_OVL
+  sleep 1
+
+  echo "Unmount hard disk image file."
+  umount sparse  
+  sleep 1
+  rm -rf sparse
+  
+  echo "Detach hard disk image file from loop device."
+  losetup -d $LOOP_DEVICE_HDD
+  sleep 1
+  
+  echo "Apply original ownership to hard disk image file."
+  chown $(logname) hdd.img
+else
+  echo "Option '$1' is not recognized. Valid options are '-f' and '-s'."
+fi