--Autopoweroff, virtual disks & dmesg

1. Fixes issue [#145](https://github.com/PartialVolume/shredos.x86_64/discussions/145)

2. Now creates /dev/loop0 & /dev/loop1 if user specifies those drives in grub.cfg

3. dmesg.txt now written to USB flash drive.

board/shredos/fsoverlay/usr/bin/archive_log.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 #
-# This script will archive the nwipe log file to a FAT32 formatted partition.
-# If there is more than one FAT32 drive this script will always archive
-# to the first drive found.
+# This script will archive the nwipe log file/s and dmesg.txt file to a
+# FAT32 formatted partition. If there is more than one FAT32 drive this
+# script will always archive to the first drive found.
 #
 # Written by PartialVolume, a component of ShredOS - the disk eraser.
 
@@ -43,11 +43,19 @@ if [ $status != 0 ] && [ $status != 32 ]; then
 else
     printf "archive_log.sh: FAT32 partition $drive is now mounted to $archive_drive_directory\n"
 
+    # Copy the dmesg.txt file over to the FAT32 partition
+    dmesg > dmesg.txt
+    cp /dmesg.txt "$archive_drive_directory/"
+    if [ $? != 0 ]; then
+	printf "archive_log.sh: Unable to copy the dmesg.txt file to the root of $drive:/\n"
+    else
+	printf "archive_log.sh: Sucessfully copied dmesg.txt to $drive:/\n" 
+    fi
+
     # Copy the nwipe log files over to the FAT32 partition
     cp /nwipe_log* "$archive_drive_directory/"
     if [ $? != 0 ]; then
         printf "archive_log.sh: Unable to copy the nwipe log files to the root of $drive:/\n"
-        exit_code=4
     else
         printf "archive_log.sh: Successfully copied the nwipe logs to $drive:/\n"
 

board/shredos/fsoverlay/usr/bin/nwipe_launcher

@@ -1,9 +1,15 @@
 #!/bin/sh
 
 # trap the ctrl+c signal
+#
 trap "echo" INT
 
+# archive dmesg.txt and nwipe logs prior to launching nwipe. This is done just
+# in case there are any display issues and we want to take a look at the dmesg data.
+/usr/bin/archive_log.sh
+
 # initialise
+#
 country_code=""
 nwipe_options_string=""
 lftp_command_line=""
@@ -11,6 +17,7 @@ lftp_command_line=""
 echo "[`date`] lftp log" > lftp.log
 
 # read the kernel command line for the loadkeys label for setting the correct keyboard layout
+#
 country_code=$(kernel_cmdline_extractor loadkeys)
 if [ $? == 0 ]
 then
@@ -21,15 +28,65 @@ then
 fi
 
 # read the kernel command line for nwipe options
+#
 nwipe_options_string=$(kernel_cmdline_extractor nwipe_options)
 if [ $? == 0 ]
 then
+	# set some flags
 	nwipe_options_flag=1
+
+	# Remove the --autopoweroff string if present from the nwipe options.
+	# We do this because we don't want nwipe itself to power down the system.
+	# ShredOS will handle the auto power down once the logs and dmesg output
+	# have been transferred to the USB flash drive after the wipe completes.
+	# One feature of nwipes autopoweroff is that it does not require the user
+	# to press a key to exit. So that nwipe doesn't pause waiting for the
+	# user to press a key which is nwipes default behaviour, we replace
+	# --autopoweroff with --nowait.
+
+	case "$nwipe_options_string" in
+	*--autopoweroff*) autopoweroff=1 ;;
+	*               ) autopoweroff=0 ;;
+	esac
+	
+	if [ $autopoweroff == 1 ]
+	then
+		echo $nwipe_options_string > nwipe_options.txt
+		sed -i 's/--autopoweroff/--nowait/g' nwipe_options.txt
+		nwipe_options_string=`cat nwipe_options.txt`
+	fi
+
+	# In addition, check whether user has specified a /dev/loop0 or /dev/loop1
+	# device and if yes, create 1Mbyte loop devices. These are used for testing.
+
+	case "$nwipe_options_string" in
+	*/dev/loop0*) createloop0=1 ;;
+	*           ) createloop0=0 ;;
+	esac
+
+	if [ $createloop0 == 1 ]
+	then
+		truncate -s 1M loopback0.img
+		losetup -fP loopback0.img
+	fi
+
+	case "$nwipe_options_string" in
+	*/dev/loop0*) createloop1=1 ;;
+	*           ) createloop1=0 ;;
+	esac
+
+	if [ $createloop1 == 1 ]
+	then
+		truncate -s 1M loopback1.img
+		losetup -fP loopback1.img
+	fi
+
 else
 	nwipe_options_flag=0	
 fi
 
 # run nwipe with a time stamped log file
+#
 while true
 do
 if [ $nwipe_options_flag == 0 ]
@@ -41,6 +98,7 @@ fi
 
 # read the kernel command line for a lftp command
 # example lftp command "open 192.168.1.60; user joe joe's_password; cd data; mput nwipe_*.txt
+#
 lftp_command_line=$(kernel_cmdline_extractor lftp)
 if [ $? == 0 ]
 then
@@ -63,6 +121,13 @@ fi
 
 /usr/bin/archive_log.sh
 
+# If the user specified --autopoweroff as a nwipe option then shutdown now 
+#
+if [ $autopoweroff == 1 ]
+then
+	init 0
+fi
+
 printf ""
 printf "Paused, press a key to restart nwipe."
 read -rsn1 input