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42 lines
657 B
C
42 lines
657 B
C
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static __attribute__((used)) char* rcsid = "$CVSHeader$";
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/*
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*
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* (c) 2004 Laurent Vivier <LaurentVivier@wanadoo.fr>
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*
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*/
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#include "libemile.h"
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#ifdef USE_16BIT_CHECKSUM
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int emile_checksum(unsigned char *addr, unsigned short length)
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{
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int j;
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unsigned short sum = 0;
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for (j = 0; j < length; j++)
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{
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sum += addr[j];
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sum = (sum << 1) | (sum >> 15);
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}
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if (sum == 0)
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sum = 0xFFFF;
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return sum;
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}
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#else
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unsigned short emile_checksum(unsigned char *addr, unsigned int length)
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{
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unsigned int sum = 0;
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unsigned int i;
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for (i = 0; i < length; i++)
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{
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sum += addr[i];
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sum <<= 1;
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sum |= (sum & 0x00010000) ? 1 : 0;
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}
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return sum;
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}
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#endif
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