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27 lines
710 B
C
27 lines
710 B
C
#include "crc16.h"
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#define CRC16_TABVAL \
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0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401, \
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0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400
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// see: https://github.com/TASVideos/desmume/blob/master/desmume/src/bios.cpp#L1070tions
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u16 crc16_quick(const void* src, u32 len) {
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const u16 tabval[] = { CRC16_TABVAL };
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u16* data = (u16*) src;
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u16 crc = 0xFFFF;
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for (len >>= 1; len; len--) {
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u16 curr = *(data++);
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for (u32 i = 0; i < 4; i++) {
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u16 tval = tabval[crc&0xF];
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crc >>= 4;
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crc ^= tval;
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tval = tabval[(curr >> (4*i))&0xF];
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crc ^= tval;
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}
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}
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return crc;
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}
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