incubator-nuttx/include/nuttx/mtd/hamming.h

140 lines
5.0 KiB
C

/****************************************************************************
* include/nuttx/mtd/hamming.h
*
* Copyright (c) 2011, Atmel Corporation
*
* 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 names NuttX nor Atmel 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_MTD_HAMMING_H
#define __INCLUDE_NUTTX_MTD_HAMMING_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* These are the possible errors when trying to verify a block of data
* encoded using a Hamming code:
*
* HAMMING_SUCCESS - Block verified without errors
* HAMMING_ERROR_SINGLEBIT - A single bit was incorrect but has been
* recovered
* HAMMING_ERROR_ECC - The original code has been corrupted
* HAMMING_ERROR_MULTIPLEBITS - Multiple bits are incorrect in the data
* and they cannot be corrected
*/
#define HAMMING_SUCCESS 0
#define HAMMING_ERROR_SINGLEBIT 1
#define HAMMING_ERROR_ECC 2
#define HAMMING_ERROR_MULTIPLEBITS 3
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#ifndef __ASSEMBLY__
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: hamming_compute256x
*
* Description:
* Computes 3-bytes hamming codes for a data block whose size is multiple
* of 256 bytes. Each 256 bytes block gets its own code.
*
* Input Parameters:
* data - Data to compute code for
* size - Data size in bytes
* code - Codes buffer
*
* Returned Value:
* None
*
****************************************************************************/
void hamming_compute256x(FAR const uint8_t *data,
size_t size,
FAR uint8_t *code);
/****************************************************************************
* Name: hamming_verify256x
*
* Description:
* Verifies 3-bytes hamming codes for a data block whose size is multiple
* of 256 bytes. Each 256-bytes block is verified with its own code.
*
* Input Parameters:
* data - Data buffer to verify
* size - Size of the data in bytes
* code - Original codes
*
* Returned Value:
* Return 0 if the data is correct, HAMMING_ERROR_SINGLEBIT if one or more
* block(s) have had a single bit corrected, or either HAMMING_ERROR_ECC
* or HAMMING_ERROR_MULTIPLEBITS.
*
****************************************************************************/
int hamming_verify256x(FAR uint8_t *data,
size_t size,
FAR const uint8_t *code);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __ASSEMBLY__ */
#endif /* __INCLUDE_NUTTX_MTD_HAMMING_H */