sysnvram.c

WINDRIVER SBC405 BSP

/* sysNvRam.c - NVRAM driver */

/* Copyright 1984-2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01b,15dec01,g_h  Fixe bug in sysNvRamGet that cause the VTS to fail
01a,03jul01,g_h  created.
*/

/*
DESCRIPTION
This library contains routines to manipulate NvRAM on Flash memory.

The macros NV_RAM_ADRS and NV_RAM_SIZE must be defined to indicate the
address and size of the Flash memory.
*/

#include "vxWorks.h"
#include "config.h"
#include "memLib.h"
#include "stdlib.h"
#include "i28F640J3Mem.h"
#include "i28F640J3Mem.c"

/***********************************************************************    
*
* sysNvRamGet - get the contents of non-volatile RAM
*
* This routine copies the contents of non-volatile memory into a specified
* string.  The string will be terminated with an EOS.
*
* NOTE: The board has no NVRAM, so we've implemented some pseudo-NVRAM
*       in the flash.
*
* RETURNS: OK or ERROR
*
* SEE ALSO: sysNvRamSet()
*/

STATUS sysNvRamGet
    (
    char * string, /* where to copy flash memory      */
    int	   strLen, /* maximum number of bytes to copy */
    int	   offset  /* byte offset into flash memory   */
    )
    {
    char * pNvRam;
    char * pString;
    int	   i;

    offset += NV_BOOT_OFFSET;   /* boot line begins at <offset> = 0 */

    /* Check that the string is entirely within the NVRAM */

    if ((offset < 0) || (strLen < 0) || ((offset + strLen) > NV_RAM_SIZE))
        return ERROR;       

    pNvRam  = (char *)(NV_RAM_ADRS + offset);
    pString =  (char *)string;

    for (i = 0; i < strLen; i++)
        *pString++ = *pNvRam++;

    *pString = EOS; /* force EOS onto nvram string */

    /* 
     * It seems that the generic boot-line code expects this function to check
     * the contents and report any errors. The default boot line is only used if
     * this function returns ERROR. So, we return ERROR if the NvRam block contine
     * only 0xFF character (= erased flash).
     */

    for (pNvRam = (char*)NV_RAM_ADRS; pNvRam < (char*)(NV_RAM_ADRS + NV_RAM_SIZE); pNvRam++)
        {
        if (*pNvRam != 0xFF)
           return (OK);
        }

    return (ERROR);
}

/***********************************************************************
*
* sysNvRamSet - write data to non-volatile RAM
*
* This routine copies the provided string to the non-volatile memory.
*
* NOTE: The board has no NVRAM, so we've implemented some pseudo-NVRAM
*       in the flash. The "NVRAM" is a small region at the very top of 
*       flash memory, and can thus be read using normal memory accesses. 
*       However, to write the data we have to read the entire top sector, 
*       modify its contents, erase the top sector, and then reprogram it.
*
* RETURNS: OK or ERROR
*
* SEE ALSO: sysNvRamGet()
*/

STATUS sysNvRamSet
    (
    char * string, /* string to be copied into flash memory */
    int	   strLen, /* maximum number of bytes to copy       */
    int	   offset  /* byte offset into flash memory         */
    )
    {
    UINT32   blockOffs;
    char   * pBlock;
    char   * pTmpBuf;

    offset += NV_BOOT_OFFSET;   /* boot line begins at <offset> = 0 */

    /* Check that the string will fit entirely into the NVRAM */

    if ((offset < 0) || (strLen < 0) || ((offset + strLen) > NV_RAM_SIZE))
        return ERROR;

    /* see if contents are actually changing */

    if (bcmp ((char *) (NV_RAM_ADRS + offset), string, strLen) == 0)
	return OK;

    /* Allocate a temporary buffer for the operation */

    pTmpBuf = (char *)malloc (FLASH_SECTOR_SIZE);
    if ( pTmpBuf == NULL )
        return ERROR;

    pBlock = (UINT8 *)((UINT32)(NV_RAM_ADRS + offset) & ~(FLASH_SECTOR_SIZE-1));

    /* Copy current contents of flash (entire sector) to the buffer */

    memcpy (pTmpBuf,(void*)pBlock,FLASH_SECTOR_SIZE);

    /* Now erase the flash sector */

    i28F640J3EraseSector ((volatile UINT8 *)pBlock);

    blockOffs = (NV_RAM_ADRS + offset) & (FLASH_SECTOR_SIZE-1);

    /* Overwrite buffer contents with specified string */

    memcpy ((void*)(pTmpBuf + blockOffs),string,strLen);

    /* Now program the flash sector */
    i28F640J3Write ((volatile UINT8 *)pBlock, pTmpBuf, FLASH_SECTOR_SIZE);

    /* 
     * We could verify the programming here, but there's big trouble if
     * it didn't work, so we won't bother. 
     */
    free (pTmpBuf);
    return OK;
}