2011-03-03 Joel Sherrill <joel.sherrill@oarcorp.com>

	PR 1749/bsps
	* Makefile: Add new test program for wrapping clock tick.
	* nanosecond_tick_wrap/.cvsignore, nanosecond_tick_wrap/Makefile,
	nanosecond_tick_wrap/README, nanosecond_tick_wrap/init.c: New files.

6 files changed, 141 insertions, 1 deletions

diff --git a/misc/ChangeLog b/misc/ChangeLog
index 6a69f09..dae7338 100644
--- a/misc/ChangeLog
+++ b/misc/ChangeLog
@@ -1,3 +1,10 @@
+2011-03-03	Joel Sherrill <joel.sherrill@oarcorp.com>
+
+	PR 1749/bsps
+	* Makefile: Add new test program for wrapping clock tick.
+	* nanosecond_tick_wrap/.cvsignore, nanosecond_tick_wrap/Makefile,
+	nanosecond_tick_wrap/README, nanosecond_tick_wrap/init.c: New files.
+
 2010-05-05	Joel Sherrill <joel.sherrill@oarcorp.com>
 
 	* qemu_vfat/Makefile, qemu_vfat/README, qemu_vfat/init.c: Now includes
diff --git a/misc/Makefile b/misc/Makefile
index cbb25ea..d89656b 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -6,7 +6,7 @@ include $(RTEMS_MAKEFILE_PATH)/Makefile.inc
 include $(RTEMS_CUSTOM)
 include $(RTEMS_ROOT)/make/directory.cfg
 
-SUBDIRS=minimum bspcmdline extract_example
+SUBDIRS=minimum bspcmdline extract_example nanosecond_tick_wrap
 
 # If the POSIX API isn't enabled, we can't build these
 ifeq ($(RTEMS_HAS_POSIX_API),yes)
diff --git a/misc/nanosecond_tick_wrap/.cvsignore b/misc/nanosecond_tick_wrap/.cvsignore
new file mode 100644
index 0000000..fecf58a
--- /dev/null
+++ b/misc/nanosecond_tick_wrap/.cvsignore
@@ -0,0 +1 @@
+o-optimize
diff --git a/misc/nanosecond_tick_wrap/Makefile b/misc/nanosecond_tick_wrap/Makefile
new file mode 100644
index 0000000..40b3244
--- /dev/null
+++ b/misc/nanosecond_tick_wrap/Makefile
@@ -0,0 +1,27 @@
+#
+#  $Id$
+#
+
+#
+#  RTEMS_MAKEFILE_PATH is typically set in an environment variable
+#
+
+PGM=${ARCH}/nanoseconds_tick_wrap.exe
+
+# optional managers required
+MANAGERS=all
+
+# C source names
+CSRCS = init.c
+COBJS = $(CSRCS:%.c=${ARCH}/%.o)
+
+include $(RTEMS_MAKEFILE_PATH)/Makefile.inc
+include $(RTEMS_CUSTOM)
+include $(PROJECT_ROOT)/make/leaf.cfg
+
+OBJS= $(COBJS) $(CXXOBJS) $(ASOBJS)
+
+all:    ${ARCH} $(PGM)
+
+$(PGM): $(OBJS)
+	$(make-exe)
diff --git a/misc/nanosecond_tick_wrap/README b/misc/nanosecond_tick_wrap/README
new file mode 100644
index 0000000..390d507
--- /dev/null
+++ b/misc/nanosecond_tick_wrap/README
@@ -0,0 +1,32 @@
+#
+#  $Id$
+#
+
+PR 1748 [1] points out a general problem that many BSPs could have in their
+nanoseconds since last tick handler.  This problem occurs when:
+
++ We are in the middle of getting TOD or Update AND
++ Clock tick counter goes to 0 
+ 
+Then the nanoseconds since last tick handler needs to account for either
+a clock interrupt pending (if the counter resets) or the counter wrapping
+below 0.  The following illustrates the interrupt pending method:
+
+iuint32_t bsp_clock_nanoseconds_since_last_tick(void)
+{
+  uint32_t clicks;
+  uint32_t usecs;
+
+  clicks = HARDWARE_COUNTER;
+
+  usecs = TO_USECS(clicks);
+  if ( Is_interrupt_pending( CLOCK_VECTOR ) )
+    usecs += rtems_configuration_get_microseconds_per_tick();
+  return usecs * 1000;
+}
+
+
+References
+==========
+
+[1] https://www.rtems.org/bugzilla/show_bug.cgi?id=1748
diff --git a/misc/nanosecond_tick_wrap/init.c b/misc/nanosecond_tick_wrap/init.c
new file mode 100644
index 0000000..1740df2
--- /dev/null
+++ b/misc/nanosecond_tick_wrap/init.c
@@ -0,0 +1,73 @@
+/*
+ *  COPYRIGHT (c) 1989-2011.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+/* Based upon code in PR1748 */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <bsp.h>
+
+#define LOOPS 1000
+uint32_t           uptime_usec[LOOPS];
+struct timespec    uptime[LOOPS];
+
+rtems_task Init(
+  rtems_task_argument argument
+)
+{
+  int              i;
+  uint32_t         t0=0;
+
+  puts( "\n\n*** Nanosecond Clock Tick Wrap Test ***" );
+  for ( i=0; i<LOOPS; i++ ) {
+
+    rtems_clock_get_uptime( &uptime[i] );
+    uptime_usec[i] = ((uint32_t)uptime[i].tv_sec * 1000000) +
+                     ((uint32_t)uptime[i].tv_nsec / 1000);
+  }
+
+  for ( i=0; i<LOOPS; i++ ) {
+    unsigned t1, usec, msec, sec;
+
+    t1 = uptime_usec[i];
+    usec = t1 % 1000;
+    msec = (t1 / 1000) % 1000;
+    sec  = t1 / 1000000;
+
+    printf(
+      "TEST:rtems=%u.%09u   t=%u.%03u.%03u   dt=%u\n",
+      uptime[i].tv_sec, uptime[i].tv_nsec, sec, msec, usec, (t1-t0)
+    );
+    t0 = t1;
+  }
+
+  puts( "*** END OF Nanosecond Clock Tick Wrap Test ***" );
+  exit(0);
+}
+
+/**************** START OF CONFIGURATION INFORMATION ****************/
+
+#define CONFIGURE_INIT
+
+#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+
+#define CONFIGURE_MAXIMUM_TASKS         1
+#define CONFIGURE_MICROSECONDS_PER_TICK \
+        (RTEMS_MILLISECONDS_TO_MICROSECONDS(1) / 2)
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#include <rtems/confdefs.h>
+
+/****************  END OF CONFIGURATION INFORMATION  ****************/
+