diff --git a/include/crc8.h b/include/crc8.h index df8434972c5..568d1deaa6f 100644 --- a/include/crc8.h +++ b/include/crc8.h @@ -59,7 +59,8 @@ extern "C" * Name: crc8part * * Description: - * Continue CRC calculation on a part of the buffer. + * Continue CRC calculation on a part of the buffer using the polynomial + * x^8+x^6+x^3+x^2+1 (Koopman, et al. "0xA6" poly). * ****************************************************************************/ @@ -76,6 +77,17 @@ uint8_t crc8part(FAR const uint8_t *src, size_t len, uint8_t crc8val); uint8_t crc8(FAR const uint8_t *src, size_t len); +/**************************************************************************** + * Name: crc8ccitt + * + * Description: + * Return an 8-bit CRC of the contents of the 'src' buffer, length 'len' + * using the polynomial x^8+x^2+x^1+1 (aka "0x07" poly). + * + ****************************************************************************/ + +uint8_t crc8ccitt(FAR const uint8_t *src, size_t len); + #undef EXTERN #ifdef __cplusplus } diff --git a/libs/libc/misc/Make.defs b/libs/libc/misc/Make.defs index 5195beea38c..a72ef15a814 100644 --- a/libs/libc/misc/Make.defs +++ b/libs/libc/misc/Make.defs @@ -1,7 +1,8 @@ ############################################################################ # libs/libc/misc/Make.defs # -# Copyright (C) 2011-2012, 2014, 2016 Gregory Nutt. All rights reserved. +# Copyright (C) 2011-2012, 2014, 2016, 2018 Gregory Nutt. All rights +# reserved. # Author: Gregory Nutt # # Redistribution and use in source and binary forms, with or without @@ -83,7 +84,7 @@ endif # CONFIG_NFILE_DESCRIPTORS > 0 # Add the miscellaneous C files to the build -CSRCS += lib_crc64.c lib_crc32.c lib_crc16.c lib_crc8.c +CSRCS += lib_crc64.c lib_crc32.c lib_crc16.c lib_crc8.c lib_crc8ccitt.c CSRCS += lib_dumpbuffer.c lib_match.c ifeq ($(CONFIG_DEBUG_FEATURES),y) diff --git a/libs/libc/misc/lib_crc8.c b/libs/libc/misc/lib_crc8.c index afa75d8c11d..8eeb0e162e4 100644 --- a/libs/libc/misc/lib_crc8.c +++ b/libs/libc/misc/lib_crc8.c @@ -1,4 +1,4 @@ -/************************************************************************************************ +/**************************************************************************** * libs/libc/misc/lib_crc8.c * * This file is a part of NuttX: @@ -35,21 +35,21 @@ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * - ************************************************************************************************/ + ****************************************************************************/ -/************************************************************************************************ +/**************************************************************************** * Included Files - ************************************************************************************************/ + ****************************************************************************/ #include #include #include -/************************************************************************************************ +/**************************************************************************** * Private Data - ************************************************************************************************/ + ****************************************************************************/ -/************************************************************************************************ +/**************************************************************************** * CRC8 table generated with: * * #define POLY 0xB2 // ((uint8_t) 0x14D) ^ 0xFF @@ -70,7 +70,7 @@ * } * } * - ************************************************************************************************/ + ****************************************************************************/ static const uint8_t crc8_tab[256] = { @@ -108,17 +108,17 @@ static const uint8_t crc8_tab[256] = 0xaf, 0x91, 0xd3, 0xed, 0x57, 0x69, 0x2b, 0x15 }; -/************************************************************************************************ +/**************************************************************************** * Public Functions - ************************************************************************************************/ + ****************************************************************************/ -/************************************************************************************************ +/**************************************************************************** * Name: crc8part * * Description: * Continue CRC calculation on a part of the buffer. * - ************************************************************************************************/ + ****************************************************************************/ uint8_t crc8part(FAR const uint8_t *src, size_t len, uint8_t crc8val) { @@ -133,14 +133,15 @@ uint8_t crc8part(FAR const uint8_t *src, size_t len, uint8_t crc8val) return crc8val ^ 0xff; } -/************************************************************************************************ +/**************************************************************************** * Name: crc8 * * Description: - * Return a 8-bit CRC of the contents of the 'src' buffer, length 'len' using a CRC with - * the polynomial x^8+x^6+x^3+x^2+1 (Koopman, et al. "0xA6" polynomial). + * Return a 8-bit CRC of the contents of the 'src' buffer, length 'len' + * using a CRC with the polynomial x^8+x^6+x^3+x^2+1 (Koopman, et al. + * "0xA6" polynomial). * - ************************************************************************************************/ + ****************************************************************************/ uint8_t crc8(FAR const uint8_t *src, size_t len) { diff --git a/libs/libc/misc/lib_crc8ccitt.c b/libs/libc/misc/lib_crc8ccitt.c new file mode 100644 index 00000000000..0b7e62957f7 --- /dev/null +++ b/libs/libc/misc/lib_crc8ccitt.c @@ -0,0 +1,113 @@ +/*************************************************************************** + * libs/libc/misc/lib_crc8ccitt.c + * + * Public domain implementation: https://3dbrew.org/wiki/CRC-8-CCITT + * + * Copyright (C) 2018 Alan Carvalho de Assis. All rights reserved. + * Author: Alan Carvalho de Assis + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USe, DATa, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARe, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ***************************************************************************/ + +/*************************************************************************** + * Included Files + ***************************************************************************/ + +#include +#include +#include + +/*************************************************************************** + * Private Data + ***************************************************************************/ + +static const uint8_t crc8_tab[256] = +{ + 0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15, + 0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d, + 0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65, + 0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d, + 0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5, + 0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd, + 0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85, + 0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd, + 0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2, + 0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea, + 0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2, + 0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a, + 0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32, + 0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a, + 0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42, + 0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a, + 0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c, + 0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4, + 0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec, + 0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4, + 0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c, + 0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44, + 0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c, + 0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34, + 0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b, + 0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63, + 0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b, + 0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13, + 0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb, + 0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83, + 0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb, + 0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3 +}; + +/*************************************************************************** + * Public Functions + ***************************************************************************/ + +/*************************************************************************** + * Name: crc8ccitt + * + * Description: + * Return a 8-bit CRC of the contents of the 'src' buffer, length 'len + * using a CRC with the polynomial x^8+x^2+x^1+1 ("0x07" polynomial). + * + ***************************************************************************/ + +uint8_t crc8ccitt(FAR const uint8_t *src, size_t len) +{ + uint8_t val = 0; + + uint8_t *pos = (uint8_t *) src; + uint8_t *end = pos + len; + + while (pos < end) + { + val = crc8_tab[val ^ *pos]; + pos++; + } + + return val; +}