#! /bin/sh
# This function checks for the presence of a real filesystem and loop-images on the target
# $1 = folder of rootfs, $2 = runlevel (defaults to 5)
check_target() {
	# Check if there is a /sbin/init or /sbin/init.sysvinit on the card
	if test -x $1/sbin/init -o -x $1/$REAL_INIT
	then
		real_fs_found=1
	else
		echo -e "Note: No INIT [$REAL_INIT] found on target"
	fi
	
	# Check for loop-images
	if (ls $1/$IMAGE_PATH/*rootfs.bin) >/dev/null 2>&1
	then
		image_found=1
	else
		echo "Note: No boot-images found in [$1/$IMAGE_PATH]"
	fi
	
	# Check if we have both, a real fs and boot-images. If so, ask the user what to boot
	if test "$real_fs_found" = 1 -a "$image_found" = 1
	then
		echo -e "\nI have found a real filesystem and boot-images on the target"
		echo -e "What do you want to boot?\n"
		
		echo -e "\t[1] The real filesystem"
		echo -e "\t[2] A loop-image"
		echo ""
		
		while test -z "$ans"
		do
			echo -n "Your choice: "
			read junk < /dev/tty1
			
			if test "$junk" = 1 -o "$junk" = 2
			then
				ans="$junk"
			fi
		done
		
		case "$ans" in
		1)	pivot_realfs "$1" "$2">/dev/tty0;;
		2)	pivot_image "$1" "$2">/dev/tty0;;
		esac
				
		exit 0
	fi

	# Boot a real filesystem	
	test "$real_fs_found" = 1 && pivot_realfs "$1" >/dev/tty0
	
	# Boot a loop-image
	test "$image_found" = 1 && pivot_image "$1" >/dev/tty0
		
	if test "$real_fs_found" != 1 -a "$image_found" != 1
	then
		die "Nothing to do!"
	fi
}

# This function pivot_root's into a real filesystem calling $newrootfs/sbin/init
# $1 = The new rootfs
pivot_realfs() {
	test -z "$2" && RL="5" || RL="$2"
	mkdir -p $1/media/ROM || die "mkdir -p $1/media/ROM failed"

	mount -o remount,ro /

	echo -n "Pivoting root..."
	if (/sbin/pivot_root $1 $1/media/ROM) 
	then
		echo "Success"

		# Interestingly, this doesn't work with the "real" mount
		# Without this command, /dev would be mounted under /media/ROM/dev after pivoting root
		/bin/busybox mount -o move /media/ROM/dev /dev

		cd /

		# Boot init.sysvinit if it is available or use /sbin/init instead
		if test -x $REAL_INIT
		then
			echo "Calling INIT [$REAL_INIT $RL]"
			exec /usr/sbin/chroot . $REAL_INIT $RL >/dev/tty0 2>&1			
		else
			echo "Calling INIT [/sbin/init $RL]"			
			exec /usr/sbin/chroot . /sbin/init $RL >/dev/tty0 2>&1			
		fi
	else
		echo "FAILED"
		die "* * * pivot_root failed! * * *" 
	fi
}

# This function loop-mounts an image-file and pivot_root's into it
# $1: The new rootfs
pivot_image() {
	test -z "$2" && RL="5" || RL="$2"
	cd $1/$IMAGE_PATH

	# Check for rootfs images on the card
	if test "`ls *rootfs.bin | wc -l | tr -d " "`" -gt 1
	then
		echo -e "\n\nPlease select a rootfs:\n"

		# Show all available images
		x=0
		for file in `ls *rootfs.bin`
		do
			let x=$x+1
			echo -e "\t\t[$x] $file"
		done

		echo ""			

		IMAGE_NAME=""
		while test -z "$IMAGE_NAME"
		do
			echo -en "Please choose one of the above: "
			read junk < /dev/tty1

			x=0
			for file in `ls *rootfs.bin`
			do
				let x=$x+1
				if test "$x" = "$junk"
				then
					IMAGE_NAME="$file"						
				fi
			done	
		done
	else
		IMAGE_NAME="`ls *rootfs.bin`"		
		test -z "$IMAGE_NAME" && die "No rootfs found (*rootfs.bin) in $1/$IMAGE_PATH"
	fi

	echo "Using [$IMAGE_NAME]"

	mkdir -p /media/image || die "mkdir -p /media/image failed"

	echo "Setting up loopback (/dev/loop0) for $IMAGE_NAME"
	losetup /dev/loop0 $1/$IMAGE_PATH/$IMAGE_NAME || die "losetup /dev/loop0 $1/$IMAGE_PATH/$IMAGE_NAME failed!"
	check_fs /dev/loop0 $IMAGE_TYPE

	echo -e "\n* * * Booting rootfs image * * *\n"


	# Busybox's "mount" doesn't seem to like "-o loop" for some reason
	# It works on collie and b0rks on poodle.
	if [ "$IMAGE_TYPE" = "" ]; then
		IMAGE_TYPE="auto"
	fi
	# If mount fails it has the tendency to spew out a _lot_ of error messages.
	# We direct the output to /dev/null so the user can see which step actually failed.
	mount -t $IMAGE_TYPE /dev/loop0 /media/image >/dev/null 2>&1 || die "mount -t $IMAGE_TYPE  /dev/loop0 /media/image failed!"

	mkdir -p /media/image/media/ROM || die "mkdir -p /media/image/media/ROM failed"

	echo -n "Pivoting root..."
	if (/sbin/pivot_root /media/image /media/image/media/ROM) 
	then
		echo "Success"

		cd /

		/bin/busybox mount -o move /media/ROM$1 $1
		/bin/busybox mount -o move /media/ROM/dev /dev
		/bin/busybox mount -o move /media/ROM/proc /proc >/dev/null 2>&1

		echo "Calling INIT"
		exec /usr/sbin/chroot . /sbin/init $RL >/dev/tty0 2>&1
	else
		echo "FAILED"
		die "* * * pivot_root failed! * * *" 
	fi


}

# This functions configures the master password for altboot if none is set
set_password() {
	mount -o remount,rw /
	if test -z "$MASTER_PASSWORD"
	then
		echo -e "\nAltboot is a boot-manager which allows to boot from SD,\nCF and NFS"
		echo -e "\nFor security reasons altboot requires a password\nto boot into init=/bin/sh."
		echo -e "${C_RED}This is *not* your root password!\nIt is used by altboot alone!${C_RESET}\n"
		#echo -e "${C_BLUE}\nNote:\tThe password will be echoed to the screen\n\tand it will be asked twice for confirmation.${C_RESET}"
		#echo -e "\nPlease enter a new master password:\n"

		while true
		do
			echo -en "\nNew password: "

			stty -echo
			read junk1 < /dev/tty0
			stty echo

			if ! test -z "$junk1"
			then
				echo -en "\nRepeat: "
				
				stty -echo
				read junk2  < /dev/tty0
				stty echo
				echo ""
				
				if test "$junk1" = "$junk2"
				then
					crypt_pw="`echo "$junk1" | md5sum | awk '{print $1}'`"
					
					if test -e /etc/altboot.cfg
					then
						sed "/^MASTER_PASSWORD/s/\(.*\=\).*/\1\"$crypt_pw\"/" /etc/altboot.cfg > /etc/altboot.cfg_
						mv /etc/altboot.cfg_ /etc/altboot.cfg
						MASTER_PASSWORD="$crypt_pw"
						echo "Password changed."
					else
						echo "/etc/altboot.cfg is missing, no password saved"
					fi
					
					break
				else
					echo -e "Passwords didn't match, try again\n"
				fi
			fi	
		done
	fi
	
}

# This function asks for altboots master password. It only returns if the correct password was supplied
verify_master_pw() {
	if ! test -z "$MASTER_PASSWORD"
	then
		auth_timeout="3"

		echo "Please enter your altboot master password"

		cnt=0
		while true
		do
			let cnt=$cnt+$auth_timeout
			echo -n "Password: "
			read junk < /dev/tty0

			if test "`echo "$junk" | md5sum | awk '{print $1}'`" = "$MASTER_PASSWORD"
			then
				break
			else
				echo "[`echo "$junk" | md5sum | awk '{print $1}'`]"
				echo "[$MASTER_PASSWORD]"
				echo "Wrong password, sleeping $cnt seconds..."
				sleep $cnt

#				if test "$cnt" -gt 10
#				then
#					break
#				fi
			fi
		done
	fi
}


check_fs() {
	if [ "$FSCK_IMAGES" = "yes" ]
	then
                FSCK=""
		if [ "$2" = "" ]; then
			FSTYPE="ext2"
		else
			FSTYPE="$2"
		fi
		case "$FSTYPE" in
		ext2 | ext3)
	        	if [ -e /sbin/fsck.ext3 ]; then
		       		FSCK="/sbin/fsck.ext3"
			elif [ -e /sbin/e3fsck ]; then
		       		FSCK="/sbin/e3fsck"
			elif [ -e /sbin/fsck.ext2 ]; then
		       		FSCK="/sbin/fsck.ext2"
			elif [ -e /sbin/e2fsck ]; then
		       		FSCK="/sbin/e2fsck"
			fi
			FSCK="$FSCK -p"
		;;
		vfat)
		    if [ -e /sbin/dosfsck ]; then
			FSCK="/sbin/dosfsck -a"
		    fi
		;;
		esac
		if [ "$FSCK" = "" ]; then
		        echo "Could not find fsck for $FSTYPE!"
		else
			echo "Checking file system on $1"
			$FSCK $1 || sleep 2
		fi
	fi
}