1 files changed, 55 insertions, 0 deletions
diff --git a/time/set_system_time.c b/time/set_system_time.c
new file mode 100644
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--- /dev/null
+++ b/time/set_system_time.c
@@ -0,0 +1,55 @@
+/*
+ * (C)2012 Michael Duane Rice All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer. Redistributions in binary
+ * form must reproduce the above copyright notice, this list of conditions
+ * and the following disclaimer in the documentation and/or other materials
+ * provided with the distribution. Neither the name of the copyright holders
+ * nor the names of contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* $Id: set_system_time.c 2356 2013-04-21 16:20:01Z swfltek $ */
+
+/*
+ * Set the system time. The values passed are assumed to represent local
+ * standard time, such as would be obtained from the typical Real Time Clock
+ * integrated circuit. It is necessary for this to be atomic, as the value may be
+ * incremented at interrupt time.
+ */
+
+#include <time.h>
+extern volatile time_t __system_time;
+
+void
+set_system_time(time_t timestamp)
+{
+
+	asm             volatile(
+			                   "in __tmp_reg__, __SREG__" "\n\t"
+				                 "cli" "\n\t"
+				 ::
+	);
+	__system_time = timestamp;
+	asm             volatile(
+			                  "out __SREG__, __tmp_reg__" "\n\t"
+				 ::
+	);
+}