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authorJay Monkman <jtm@smoothsmoothie.com>2005-02-25 05:18:07 +0000
committerJay Monkman <jtm@smoothsmoothie.com>2005-02-25 05:18:07 +0000
commit7cde240ce85e3f5ffd69e970e36dd722a87c02c5 (patch)
treebf10fa3feefe87805981929c5a05a6a66c86567b /c/src/lib/libbsp/mips/csb350/timer/timer.c
parent2005-02-24 Jay Monkman (diff)
downloadrtems-7cde240ce85e3f5ffd69e970e36dd722a87c02c5.tar.bz2
2005-02-24 Jay Monkman <jtm@lopingdog.com>
* acinclude.m4: Added csb350 to list of BSPs. * csb350/Makefile.am, csb350/README, csb350/bsp_specs, csb350/configure.ac, csb350/times, csb350/clock/clockdrv.c, csb350/console/console-io.c, csb350/include/bsp.h, csb350/include/tm27.h, csb350/network/network.c, csb350/start/regs.S, csb350/start/start.S, csb350/startup/bspclean.c, csb350/startup/bspstart.c, csb350/startup/linkcmds, csb350/timer/timer.c: New BSP.
Diffstat (limited to 'c/src/lib/libbsp/mips/csb350/timer/timer.c')
-rw-r--r--c/src/lib/libbsp/mips/csb350/timer/timer.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/mips/csb350/timer/timer.c b/c/src/lib/libbsp/mips/csb350/timer/timer.c
new file mode 100644
index 0000000000..7dd684db1a
--- /dev/null
+++ b/c/src/lib/libbsp/mips/csb350/timer/timer.c
@@ -0,0 +1,63 @@
+/*
+ * This file implements a benchmark timer using the count/compare
+ * CP0 registers.
+ *
+ * Copyright (c) 2005 by Cogent Computer Systems
+ * Written by Jay Monkman <jtm@lopingdog.com>
+ *
+ * The license and distribution terms for this file may be
+ * found in found in the file LICENSE in this distribution or at
+ * http://www.OARcorp.com/rtems/license.html.
+ *
+ * $Id$
+ */
+
+#include <assert.h>
+
+#include <bsp.h>
+
+rtems_boolean Timer_driver_Find_average_overhead;
+unsigned32 tstart;
+
+void Timer_initialize()
+{
+ asm volatile ("mfc0 %0, $9\n" : "=r" (tstart));
+ /* tick time in picooseconds */
+}
+
+#define AVG_OVERHEAD 0 /* It typically takes N instructions */
+ /* to start/stop the timer. */
+#define LEAST_VALID 1 /* Don't trust a value lower than this */
+ /* tx39 simulator can count instructions. :) */
+
+int Read_timer()
+{
+ unsigned32 total;
+ unsigned32 cnt;
+
+ asm volatile ("mfc0 %0, $9\n" : "=r" (cnt));
+
+ total = cnt - tstart;
+ total = (total * 1000) / 396; /* convert to nanoseconds */
+
+
+ if ( Timer_driver_Find_average_overhead == 1 )
+ return total; /* in one microsecond units */
+
+ 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;
+}