Merge devel code into the trunk.

[tinyos-2.x.git] / support / sdk / java / net / tinyos / util / Crc.java

diff --git a/support/sdk/java/net/tinyos/util/Crc.java b/support/sdk/java/net/tinyos/util/Crc.java
new file mode 100644 (file)
index 0000000..f9b5fc4
--- /dev/null
+++ b/support/sdk/java/net/tinyos/util/Crc.java
@@ -0,0 +1,78 @@
+// $Id$
+
+/*                                                                     tab:4
+ * "Copyright (c) 2000-2003 The Regents of the University  of California.  
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without written agreement is
+ * hereby granted, provided that the above copyright notice, the following
+ * two paragraphs and the author appear in all copies of this software.
+ * 
+ * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
+ * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
+ * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
+ *
+ * Copyright (c) 2002-2003 Intel Corporation
+ * All rights reserved.
+ *
+ * This file is distributed under the terms in the attached INTEL-LICENSE     
+ * file. If you do not find these files, copies can be found by writing to
+ * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300, Berkeley, CA, 
+ * 94704.  Attention:  Intel License Inquiry.
+ */
+package net.tinyos.util;
+
+public class Crc {
+    public static int calcByte(int crc, int b) {
+      crc = crc ^ (int)b << 8;
+
+      for (int i = 0; i < 8; i++) {
+       if ((crc & 0x8000) == 0x8000)
+         crc = crc << 1 ^ 0x1021;
+       else
+         crc = crc << 1;
+      }
+
+      return crc & 0xffff;
+    }
+
+    public static int calc(byte[] packet, int index, int count) {
+       int crc = 0;
+       int i;
+
+       while (count > 0) {
+           crc = calcByte(crc, packet[index++]);
+           count--;
+       }
+       return crc;
+    }
+
+    public static int calc(byte[] packet, int count) {
+       return calc(packet, 0, count);
+    }
+
+    public static void set(byte[] packet) {
+        int crc = Crc.calc(packet, packet.length - 2);
+
+        packet[packet.length - 2] = (byte) (crc & 0xFF);
+        packet[packet.length - 1] = (byte) ((crc >> 8) & 0xFF);
+    }
+
+    public static void main(String[] args) {
+       byte[] ia = new byte[args.length];
+
+       for (int i = 0; i < args.length; i++)
+           try {
+               ia[i] = Integer.decode(args[i]).byteValue();
+           } catch (NumberFormatException e) { }
+       System.out.println(Integer.toHexString(calc(ia, ia.length)));
+    }
+}