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+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Original source:
+ * Copyright (c) 2003 by Joergen Ibsen / Jibz
+ *
+ * Rockbox adaptation:
+ * Copyright (c) 2010 by Marcin Bukat
+ *
+ * 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.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/*
+ * CRC32 checksum
+ *
+ * Copyright (c) 1998-2003 by Joergen Ibsen / Jibz
+ * All Rights Reserved
+ *
+ * http://www.ibsensoftware.com/
+ *
+ * This software is provided 'as-is', without any express
+ * or implied warranty. In no event will the authors be
+ * held liable for any damages arising from the use of
+ * this software.
+ *
+ * Permission is granted to anyone to use this software
+ * for any purpose, including commercial applications,
+ * and to alter it and redistribute it freely, subject to
+ * the following restrictions:
+ *
+ * 1. The origin of this software must not be
+ * misrepresented; you must not claim that you
+ * wrote the original software. If you use this
+ * software in a product, an acknowledgment in
+ * the product documentation would be appreciated
+ * but is not required.
+ *
+ * 2. Altered source versions must be plainly marked
+ * as such, and must not be misrepresented as
+ * being the original software.
+ *
+ * 3. This notice may not be removed or altered from
+ * any source distribution.
+ */
+
+/*
+ * CRC32 algorithm taken from the zlib source, which is
+ * Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
+ */
+
+#include "tinf.h"
+
+static const unsigned int tinf_crc32tab[16] = {
+ 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 0x76dc4190,
+ 0x6b6b51f4, 0x4db26158, 0x5005713c, 0xedb88320, 0xf00f9344,
+ 0xd6d6a3e8, 0xcb61b38c, 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278,
+ 0xbdbdf21c
+};
+
+unsigned int tinf_crc32(const void *data, unsigned int length)
+{
+ const unsigned char *buf = (const unsigned char *)data;
+ unsigned int crc = 0xffffffff;
+ unsigned int i;
+
+ if (length == 0) return 0;
+
+ for (i = 0; i < length; ++i)
+ {
+ crc ^= buf[i];
+ crc = tinf_crc32tab[crc & 0x0f] ^ (crc >> 4);
+ crc = tinf_crc32tab[crc & 0x0f] ^ (crc >> 4);
+ }
+
+ return crc ^ 0xffffffff;
+}