sysnvram.c

Vxworks的bsp软件开发包(基于wrPpmc74xx)

/* sysNvRam.c - NVRAM driver */

/* Copyright 1984-2002 Wind River Systems, Inc. */

/*
modification history
--------------------
01b,15dec01,g_h  Fixe bug in sysNvRamGet that cause the VTS to fail
01a,22jun01,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.

INCLUDES: amd29LV800TMem.h
*/

#include "vxWorks.h"
#include "config.h"
#include "memLib.h"
#include "stdlib.h"
#include "amd29LV800TMem.h"
#include "amd29LV800TMem.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.
*
* INTERNAL
* 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.
*
* INTERNAL
* 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 */
    amd29LV800TEraseSector ((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 */
    amd29LV800TWrite ((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;
    }