userspace/rootfs_override: save date over restarts

--add running all /etc/init.d/K* scripts before restart
--add /etc/init.d/K90time_save.sh script to save current date
--set saved date in case date cannot be received from ntp
--update developer manual

Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

doc/wrs-developer-manual.in

@@ -1623,7 +1623,7 @@ allows to make some sense of the overall area.  The structure
 is filled by library functions and accessed by shared memory users.
 You can see how it is used in @t{tools/wrs_dump_shmem.c}.
 
-The following functions are defined. Pleae look in the source code
+The following functions are defined. Please look in the source code
 for details about how they are used:
 
 @table @code
@@ -1798,6 +1798,22 @@ We may also consider to use one of the kernel's mechanisms for persistent
 storage of information across reboots, to recover panic messages
 after a reboot.
 
+@c ==========================================================================
+@node Time keeping over restarts
+@section Time keeping over restarts
+
+At normal restart, current time is saved in @t{/update/saved_date}.
+Later, at boot switch tries to retrieve correct time from ntp server
+if configured in dot-config.
+If no correct date can be retrieved via ntp, switch tries to set date stored in
+@t{/update/saved_date}. Please note that at crash, power down or
+reset by reset button no date information is saved. After such restart switch
+will set date to last gentle reboot or to 1st of January 1970 if there were no
+gentle restarts before.
+
+Date set from file @t{/update/saved_date} is never correct, but is based on
+best effort principle.
+
 @c ==========================================================================
 @node SDB and Hardware Information
 @section SDB and Hardware Information

userspace/rootfs_override/etc/init.d/K90time_save.sh

+#!/bin/sh
+
+echo "Saving time "`date +%Y.%m.%d-%H:%M:%S`
+date +%Y.%m.%d-%H:%M:%S > /update/saved_date

userspace/rootfs_override/etc/init.d/S70wr_date

@@ -4,18 +4,32 @@
 /wr/bin/wr_date get > /dev/null
 
 F=/wr/etc/wr_date.conf
-# if there is no config file, do nothing else.
-test -f $F || exit 0
 
-# pick the first server, if any
-S=$(grep 'ntpserver' $F | sed 's/ntpserver//' | head -n 1)
+date_set=0
+# check whether there is config file
+if [ -f $F ]; then
+	# pick the first server, if any
+	S=$(grep 'ntpserver' $F | sed 's/ntpserver//' | head -n 1)
+	# check whether server found
+	if [ -n "$S" ]; then
 
-# if none, exit
-test -z "$S" && exit 0
-
-# pick busybox ntpd explicitly, to avoid real ntpd instances
-echo "Setting host time using ntpd"
-busybox ntpd -n -q -p $S
-
-echo "Setting WR time from host time"
-/wr/bin/wr_date set host
+		# pick busybox ntpd explicitly, to avoid real ntpd instances
+		echo "Setting host time using ntpd"
+		busybox ntpd -n -q -p $S
+		if [ $? == 0 ]; then
+			# successful
+			echo "Date set from $S"
+			date_set=1
+			echo "Setting WR time from host time"
+			/wr/bin/wr_date set host
+		fi
+	fi
+fi
+# if ntp failed, try to restore date saved before last reboot
+if [ $date_set = 0 ] && [ -f /update/update_date ]; then
+	#date is not accurate but no better idea.
+	echo "Restore saved time"
+	date -s `cat /update/update_date`
+	echo "Setting WR time from host time"
+	/wr/bin/wr_date set host
+fi

userspace/rootfs_override/etc/init.d/rcK

+#!/bin/sh
+if [ -n "$WRS_VERBOSE" ]; then
+    set -x;
+    SH_X="sh -x"
+fi
+
+# Stop all init scripts in /etc/init.d
+# executing them in numerical order.
+#
+
+for i in /etc/init.d/K??* ;do
+
+     # Ignore dangling symlinks (if any).
+     [ ! -f "$i" ] && continue
+
+     case "$i" in
+	*.sh)
+	    # Source shell script for speed.
+	    (
+		trap - INT QUIT TSTP
+		set stop
+		. $i
+	    )
+	    ;;
+	*)
+	    # No sh extension, so fork subprocess.
+	    eval $SH_X $i stop
+	    ;;
+    esac
+done
+

userspace/rootfs_override/etc/inittab

@@ -29,5 +29,7 @@ ttyGS0::respawn:/bin/ash --login
 ttyS0::respawn:/bin/ash --login
 
 # Stuff to do before rebooting
+# run all /etc/init.d/K* scripts
+null::shutdown:/etc/init.d/rcK -a -r
 null::shutdown:/bin/umount -a -r