eeprom.c

avr上的RTOS

/*
 * Copyright (C) 2000-2004 by ETH Zurich
 *
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 * modification, are permitted provided that the following conditions
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 *
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 *    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 of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ETH ZURICH 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 ETH ZURICH
 *  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
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 */


/* 
 * unix_eeprom.c - avr eeprom functions for unix emulation
 *
 * 2004.08.05 Matthias Ringwald <[e-mail]>
 *
 */

/**
\brief Provides the avr eeprom api. It uses the file 'btnode_eerpom.bin' to store
 its content.
*/

/* avoid stdio nut wrapper */
#define NO_STDIO_NUT_WRAPPER

#include <stdio.h>

// eeprom image
static FILE *eepromFile = 0;

// asserts eepromFile open and positions read/write pointer
void unix_eeprom_acces(const void *addr)
{
    if (eepromFile == 0) {
        // create file if it doenst exist
        eepromFile = fopen("eeprom.bin", "a");
        if (eepromFile)
            fclose(eepromFile);
        // open file for read & write
        eepromFile = fopen("eeprom.bin", "r+");
        if (eepromFile == 0) {
            printf("ERROR: Open 'eeprom.bin' failed\n\r");
        }
    }
    if (eepromFile) {
        fseek(eepromFile, (long) addr, SEEK_SET);
    }
}

 /** \ingroup unix_eeprom
    write a byte \c val to EEPROM address \c addr */
void eeprom_write_byte(unsigned char *addr, unsigned char val)
{
    unix_eeprom_acces(addr);
    fwrite(&val, 1, 1, eepromFile);
    fflush(eepromFile);
}

/** \ingroup unix_eeprom
    read a block of \c n bytes from EEPROM address \c addr to
    \c buf */
void eeprom_read_block(void *buf, const void *addr, size_t n)
{
    u_short count;
    unix_eeprom_acces(addr);
    count = fread(buf, 1, n, eepromFile);

    // fill missing values
    while (count < n) {
        ((u_char *) buf)[count++] = 0xff;
    }
}

/** \ingroup unix_eeprom
    read one byte from EEPROM address \c addr */
u_char eeprom_read_byte(const unsigned char *addr)
{
    u_char result;
    u_short count;
    unix_eeprom_acces(addr);
    count = fread(&result, 1, 1, eepromFile);
    if (count != 1)
        return -1;
    return result;
}

/** \ingroup unix_eeprom
    read one 16-bit word (little endian) from EEPROM address \c addr */
u_short eeprom_read_word(const unsigned short *addr)
{
    u_short result;
    u_short count;
    unix_eeprom_acces(addr);
    count = fread(&result, 1, 2, eepromFile);
    if (count != 2)
        return -1;
    return result;
}