nvramtofloppy.c

Vxworks下的C例子程序

/* nvRamToFloppy.c - non-volatile RAM mapping to floppy for boot line storage */

/* Copyright 1996 RST Software Industries, Ltd, Israel */

/*
modification history
--------------------
01a,25dec96,vlad@rst  created.
*/

/*
DESCRIPTION
This library simulates NVRAM on a floppy disk for boot line
storage only. This library is intended for PC-x86 targets, that
are not accompany with NVRAM or flash memory and obtain bootrom
image from floppy disk.
*/

#ifndef __NVRAM_TO_FLOPPY__
#define __NVRAM_TO_FLOPPY__

/* includes */
 
#include <vxWorks.h>
#include "drv/mem/memDev.h"

/* defines */

/* globals */
/* device names to search for */
char *	nvBlDevNames[] = {"/fd0"/* default name */ , "A:"};
int	nvBlDevNameInd = (-1);

/******************************************************************************
* nvFloppyDevInit - to init DOSFS on the floppy device.
*
* RETURNS OK.
*/

LOCAL STATUS nvFloppyDevInit()
    {
    int	fd;
    BLK_DEV *pBootDev;

    if( nvBlDevNameInd != (-1) )
	return OK;
    for( nvBlDevNameInd = 0; nvBlDevNameInd < NELEMENTS( nvBlDevNames );
	 nvBlDevNameInd ++ )
    	{
    	fd = open( nvBlDevNames[ nvBlDevNameInd ], O_RDONLY, 0 );
    	if( fd != ERROR )
    	    goto ret;
    	}

    nvBlDevNameInd = (-1);

    /* create floppy device */
    fdDrv (FD_INT_VEC, FD_INT_LVL);     /* initialize floppy disk driver */
    if ((pBootDev = fdDevCreate (0, 0, 0, 0)) == NULL)
        {
        printErr ("fdDevCreate failed.\n");
        return (ERROR);
        }

    dosFsInit (NUM_DOSFS_FILES);        /* initialize DOS-FS */

    if (dosFsDevInit ( nvBlDevNames[ 0 ], pBootDev, NULL) == NULL)
        {
        printErr ("dosFsDevInit failed.\n");
        return (ERROR);
        }
    fd = open( nvBlDevNames[ 0 ], O_RDONLY, 0 );
    if( fd == ERROR )
        { 
        printErr ("floppy device %s create error\n", nvBlDevNames[ 0 ] ); 
        return (ERROR); 
        } 
    printErr("Floppy device %s created\n", nvBlDevNames[ 0 ] );

    nvBlDevNameInd = 0;

ret:
    close( fd );
    return OK;
    }

/*******************************************************************************
*
* sysNvRamSet - write boot linre onto floppy disk
*
* This routine copies a specified string into bootline file on the floppy
* disk.
*
* RETURNS: OK, or ERROR if access is outside the non-volatile RAM range.
*
* SEE ALSO: sysNvRamGet()
*/

STATUS sysNvRamSet
    (
    char *string,     /* string to be copied into non-volatile RAM */
    int strLen,       /* maximum number of bytes to copy           */
    int offset        /* byte offset into non-volatile RAM         */
    )
    {
    int fd;
    char	name[ 20 ] = {EOS};

    printErr("Storing boot line to file. Please wait...\n");

    if( nvFloppyDevInit() == ERROR )
    	return ERROR;

    sprintf(name,"%s/bootline.dat", nvBlDevNames[ nvBlDevNameInd ] );
    fd = creat( name, O_WRONLY );
    if( fd == ERROR )
    	{
    	printErr("Error creating file to store boot line on floppy disk\n");
    	return ERROR;
    	}
    if( write(fd, string, strLen ) < strLen )
        {
        printErr("Error storing boot line on floppy disk\n");
        return ERROR;
        }
    close( fd ); 
    return OK;
    }

/*******************************************************************************
* sysNvRamGet - get boot line from floppy disk.
*
* This routine copies the contents of bootline file into a specified
* string.  The string will be terminated with an EOS.
*
* RETURNS: OK, or ERROR if access is outside the non-volatile RAM range.
*
* SEE ALSO: sysNvRamSet()
*/

STATUS sysNvRamGet
    (
    char *string,     /* string to be copied into non-volatile RAM */
    int strLen,       /* maximum number of bytes to copy           */
    int offset        /* byte offset into non-volatile RAM         */
    )
    {
    int fd;
    char        name[ 20 ] = {EOS};

    printErr("Reading boot line\n");

    if( nvFloppyDevInit() == ERROR )
        return ERROR;

    sprintf(name,"%s/bootline.dat", nvBlDevNames[ nvBlDevNameInd ] );
    fd = open( name, O_RDONLY, 0 );
    if( fd == ERROR )
        {
        printErr("Error: boot line file %s not found\n", name );
        return ERROR;
        }
    if( read(fd, string, strLen ) == ERROR )
        {
        printErr("Error reading boot line from floppy disk\n");
        return ERROR;
        }
    string [strLen] = EOS;
    close( fd );
    return OK;
    }

#endif /* __NVRAM_TO_FLOPPY__ */