1 files changed, 93 insertions, 0 deletions

diff --git a/firmware/common/crc32-mi4.c b/firmware/common/crc32-mi4.c
new file mode 100644
index 0000000000..8956364f10
--- /dev/null
+++ b/firmware/common/crc32-mi4.c
@@ -0,0 +1,93 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id: crc32.c 10464 2006-08-05 20:19:10Z miipekk $
+ *
+ * Copyright (C) 2007 Barry Wardell
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/*
+ * We can't use the CRC32 implementation in the firmware library as it uses a
+ * different polynomial. The polynomial needed is 0xEDB88320L
+ *
+ * CRC32 implementation taken from:
+ *
+ * efone - Distributed internet phone system.
+ *
+ * (c) 1999,2000 Krzysztof Dabrowski
+ * (c) 1999,2000 ElysiuM deeZine
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+/* based on implementation by Finn Yannick Jacobs */
+
+
+
+/* crc_tab[] -- this crcTable is being build by chksum_crc32GenTab().
+ *      so make sure, you call it before using the other
+ *      functions!
+ */
+static unsigned int crc_tab[256];
+
+/* chksum_crc() -- to a given block, this one calculates the
+ *              crc32-checksum until the length is
+ *              reached. the crc32-checksum will be
+ *              the result.
+ */
+unsigned int chksum_crc32 (unsigned char *block, unsigned int length)
+{
+   register unsigned long crc;
+   unsigned long i;
+
+   crc = 0;
+   for (i = 0; i < length; i++)
+   {
+      crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_tab[(crc ^ *block++) & 0xFF];
+   }
+   return (crc);
+}
+
+/* chksum_crc32gentab() --      to a global crc_tab[256], this one will
+ *              calculate the crcTable for crc32-checksums.
+ *              it is generated to the polynom [..]
+ */
+
+void chksum_crc32gentab (void)
+{
+   unsigned long crc, poly;
+   int i, j;
+
+   poly = 0xEDB88320L;
+   for (i = 0; i < 256; i++)
+   {
+      crc = i;
+      for (j = 8; j > 0; j--)
+      {
+     if (crc & 1)
+     {
+        crc = (crc >> 1) ^ poly;
+     }
+     else
+     {
+        crc >>= 1;
+     }
+      }
+      crc_tab[i] = crc;
+   }
+}