Added new software bundle 'mll_utils'. Currently it contains a disk nuke utility/script which securely wipes partitions/disks.

src/.config

@@ -148,10 +148,11 @@ COPY_SOURCE_ISO=true
 # dropbear   - SSH server and client.
 # java       - installs Oracle's JRE or JDK. Manual preparations are required.
 # felix      - Apache Felix OSGi framework.
+# mll_utils  - set of executable utilities (mll-*).
 #
 # Refer to the README file for more information.
 #
-#OVERLAY_BUNDLES=glibc_full,links,dropbear,java,felix
+#OVERLAY_BUNDLES=glibc_full,links,dropbear,java,felix,mll_utils
 
 # This property enables the standard penguin boot logo in the upper left corner
 # of the screen. The property is used in 'xx_build_kernel.sh'. The default value

src/overlay_mll_utils.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+time sh overlay_mll_utils_01_prepare.sh
+time sh overlay_mll_utils_02_disk_erase.sh
+time sh overlay_mll_utils_03_install.sh
+

src/overlay_mll_utils_01_prepare.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+SRC_DIR=$(pwd)
+
+echo "Preparing the Minimal Linux Live utilities folder. This may take a while..."
+rm -rf work/overlay/mll_utils
+mkdir -p work/overlay/mll_utils/sbin
+
+echo "Miminal Linux Live utilities folder has been prepared."
+
+cd $SRC_DIR
+

src/overlay_mll_utils_02_disk_erase.sh

@@ -0,0 +1,80 @@
+#!/bin/sh
+
+SRC_DIR=$(pwd)
+
+if [ ! -d "$SRC_DIR/work/overlay/mll_utils" ] ; then
+  echo "The directory $SRC_DIR/work/overlay/mll_utils does not exist. Cannot continue."
+  exit 1
+fi
+
+cd work/overlay/mll_utils
+
+# 'mll-disk-erase' BEGIN
+
+# This script erases disks in secure way by overwriting all sectors with random
+# data. Data recovery is impossible even for NSA and CIA.
+cat << CEOF > sbin/mll-disk-erase
+#!/bin/sh
+
+PRINT_HELP=false
+
+if [ "\$1" = "" -o "\$1" = "-h" -o "\$1" = "--help" ] ; then
+  PRINT_HELP=true
+fi
+
+# Put more business logic here (if needed).
+
+if [ "\$PRINT_HELP" = "true" ] ; then
+  cat << DEOF
+  This utility wipes disk partitions or entire disks in secure way by
+  overwriting all sectors with random data. Use the '-h' or '--help' option
+  to print again this information. Requires root permissions.
+
+  Usage: mll-disk-erase DEVICE [loops]
+
+  DEVICE    The device which will be wiped. Specify only the name, e.g. 'sda'.
+            The utility will automatically convert this to '/dev/sda' and will
+            exit with warning message if the actual device does not exist.
+
+  loops     How many times to wipe the specified partition or disk. The default
+            value is 1. Use higher value for multiple wipes in order to ensure
+            that no one can recover your data.
+
+  mll-disk-erase sdb 8
+
+  The above example wipes '/dev/sdb' 8 times in row.
+DEOF
+  
+  exit 0
+fi
+
+if [ ! "$(id -u)" = "0" ] ; then
+  echo "You need root permissions. Use '-h' or '--help' for more information."
+  exit 1
+fi
+
+if [ ! -e /dev/\$1 ] ; then
+  echo "Device '/dev/\$1' does not exist. Use '-h' or '--help' for more information."
+  exit 1
+fi
+
+NUM_LOOPS=1
+
+if [ ! "\$2" = "" ] ; then
+  NUM_LOOPS=\$2
+fi
+
+for n in \$(seq \$NUM_LOOPS) ; do
+  dd if=/dev/urandom of=/dev/\$1 bs=1024b conv=notrunc
+done 
+
+CEOF
+
+chmod +rx sbin/mll-disk-erase
+
+# 'mll-disk-erase' END
+
+echo "Utility script 'mll-disk-erase' has been generated."
+
+cd $SRC_DIR
+

src/overlay_mll_utils_03_install.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+SRC_DIR=$(pwd)
+
+if [ ! -d "$SRC_DIR/work/overlay/mll_utils" ] ; then
+  echo "The directory $SRC_DIR/work/overlay/mll_utils does not exist. Cannot continue."
+  exit 1
+fi
+
+# Copy all generated files to the source overlay folder.
+cp -r $SRC_DIR/work/overlay/mll_utils/* \
+  $SRC_DIR/work/src/minimal_overlay
+
+echo "All utilities have been installed."
+
+cd $SRC_DIR
+