1 files changed, 96 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/i386/force386/timer/timer.c b/c/src/lib/libbsp/i386/force386/timer/timer.c
new file mode 100644
index 0000000000..1896e15a23
--- /dev/null
+++ b/c/src/lib/libbsp/i386/force386/timer/timer.c
@@ -0,0 +1,96 @@
+/*  Timer_init()
+ *
+ *  This routine initializes the timer on the FORCE CPU-386 board.
+ *
+ *  Input parameters:  NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  NOTE: This routine will not work if the optimizer is enabled
+ *        for some compilers.  The multiple writes to the Z8036
+ *        may be optimized away.
+ *
+ *        It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+
+#include <rtems.h>
+#include <bsp.h>
+
+int Ttimer_val;
+rtems_boolean Timer_driver_Find_average_overhead;
+
+rtems_isr timerisr();
+
+void Timer_initialize()
+{
+
+  (void) set_vector( timerisr, 0x38, 0 );   /* install ISR */
+
+  Ttimer_val = 0;                           /* clear timer ISR count */
+
+  outport_byte( IERA, 0x40 );               /* disable interrupt */
+  outport_byte( TBCR, 0x40 );               /* stop the timer */
+  outport_byte( TBDR, 250 );                /* 250 units */
+
+  outport_byte( TBCR, 0x11 );               /* reset it, delay mode, 4X */
+#if 0
+  outport_byte( TBCR, 0x13 );               /* reset it, delay mode, 16X */
+#endif
+
+  outport_byte( IERA, 0x41 );               /* enable interrupt */
+
+}
+
+#define AVG_OVERHEAD      3  /* It typically takes 3.0 microseconds */
+                             /* (3 ticks) to start/stop the timer. */
+#define LEAST_VALID       4  /* Don't trust a value lower than this */
+
+int Read_timer()
+{
+  register rtems_unsigned32 clicks;
+  register rtems_unsigned32 total;
+
+  outport_byte( TBCR, 0x00 );        /* stop the timer */
+
+  inport_byte( TBDR, clicks );
+
+  total = Ttimer_val + 250 - clicks;
+
+  outport_byte( TBCR, 0x00 );  /* initial value */
+  outport_byte( IERA, 0x40 );  /* disable interrupt */
+
+  /* ??? Is "do not restore old vector" causing problems? */
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in one microsecond units */
+
+  else {
+    if ( total < LEAST_VALID )
+      return 0;            /* below timer resolution */
+    return (total - AVG_OVERHEAD);
+  }
+}
+
+rtems_status_code Empty_function( void )
+{
+  return RTEMS_SUCCESSFUL;
+}
+
+void Set_find_average_overhead(
+  rtems_boolean find_flag
+)
+{
+  Timer_driver_Find_average_overhead = find_flag;
+}