| /* |
| * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved. |
| * |
| * This software may be freely used, copied, modified, and distributed |
| * provided that the above copyright notice is preserved in all copies of the |
| * software. |
| */ |
| |
| /* -*-C-*- |
| * |
| * $Revision$ |
| * $Date$ |
| * |
| * |
| * crc.h - describes some "standard" CRC calculation routines. |
| */ |
| #ifndef angel_crc_h |
| #define angel_crc_h |
| |
| /* |
| * manifests |
| */ |
| |
| /* |
| * When using "crc32" or "crc16" these initial CRC values must be given to |
| * the respective function the first time it is called. The function can |
| * then be called with the return value from the last call of the function |
| * to generate a running CRC over multiple data blocks. |
| * When the last data block has been processed using the "crc32" algorithm |
| * the CRC value should be inverted to produce the final CRC value: |
| * e.g. CRC = ~CRC |
| */ |
| |
| #define startCRC32 (0xFFFFFFFF) /* CRC initialised to all 1s */ |
| #define startCRC16 (0x0000) /* CRC initialised to all 0s */ |
| |
| /* |
| * For the CRC-32 residual to be calculated correctly requires that the CRC |
| * value is in memory little-endian due to the byte read, bit-ordering |
| * nature of the algorithm. |
| */ |
| #define CRC32residual (0xDEBB20E3) /* good CRC-32 residual */ |
| |
| |
| /**********************************************************************/ |
| |
| /* |
| * exported functions |
| */ |
| |
| /* |
| * Function: crc32 |
| * Purpose: Provides a table driven implementation of the IEEE-802.3 |
| * 32-bit CRC algorithm for byte data. |
| * |
| * Params: |
| * Input: address pointer to the byte data |
| * size number of bytes of data to be processed |
| * crc initial CRC value to be used (can be the output |
| * from a previous call to this function). |
| * Returns: |
| * OK: 32-bit CRC value for the specified data |
| */ |
| extern unsigned int crc32(unsigned char *address, unsigned int size, |
| unsigned int crc); |
| |
| /**********************************************************************/ |
| |
| /* |
| * |
| * Function: crc16 |
| * Purpose: Generates a table driven 16-bit CRC-CCITT for byte data |
| * |
| * Params: |
| * Input: address pointer to the byte data |
| * size number of bytes of data to be processed |
| * crc initial CRC value to be used (can be the output |
| * from a previous call to this function). |
| * |
| * Returns: |
| * OK: 16-bit CRC value for the specified data |
| */ |
| extern unsigned short crc16(unsigned char *address, unsigned int size, |
| unsigned short crc); |
| |
| /**********************************************************************/ |
| |
| #endif /* !defined(angel_crc_h) */ |
| |
| /* EOF crc.h */ |
