while (pSpi->pRxBdBase->statusMode & SPI_TRANS_RX_BD_EMPTY)
     {
       /* Busy-wait. */
       ;
     }
 
   /* De-assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) |= 0x00001;
 
   /* Copy EEPROM data into given string. */
   bcopyBytes(&eeprom_data[3], string, strLen);
   return(OK);
 }	/* end of sysNvRamGet */
 
 
 /******************************************************************************
 *
 * sysNvRamSet - write to non-volatile RAM
 *
 * This routine copies a specified string into non-volatile RAM.
 *
 * RETURNS: OK, or ERROR if access is outside the non-volatile RAM range.
 *
 * SEE ALSO: sysNvRamGet(), sysHwSpiInit()
 */
 
 STATUS	sysNvRamSet(
                     char*	string,
                     int		strLen,
                     int		offset)
 {
   /* (Note - given offset is not used by this routine.) */
 
   UCHAR	dataChar;
   USHORT	int_offset = 0;
   SPI_DEV*	pSpi;
 
   pSpi = &spiDev;
 
   if (pSpi->init != TRUE)
       return(ERROR);
 
   offset += NV_BOOT_OFFSET;   /* boot line begins at <offset> = 0 */
   
   if ((offset < 0)
       || (strLen < 0)
       || ((offset + strLen) > SPI_SERIAL_EEPROM_SZ))
     return (ERROR);
 
   int_offset = offset;
 
   while (strLen)
     {
       sysNvRamWriteEnable();
       dataChar = (UCHAR) *string++;
       sysNvRamWriteByte(dataChar, int_offset++);
       strLen--;
     }
 
   return(OK);
 }	/* end of sysNvRamSet */
 
 
 /******************************************************************************
 *
 * sysNvRamWriteEnable - enable writing to NVRAM
 *
 * This routine enables writing to NVRAM
 *
 * RETURNS: none
 *
 * NOMANUAL
 */
 
 LOCAL void	sysNvRamWriteEnable(
                                 void)
 {
   SPI_DEV*	pSpi;
 
 
   pSpi = &spiDev;
 
   /* Wait for EEPROM to become ready. */
   while (sysNvRamGetStatus() == ERROR)
     {
       /* Busy-wait. */
       ;
     }
 
   /* Assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) &= 0x3FFFE;
 
   /* Wait for transmit to finish (first). */
   while (pSpi->pTxBdBase->statusMode & SPI_TRANS_TX_BD_READY)
     {
       /* Busy-wait. */
       ;
     }
 
   /* Disable SPI (serial port interface). */
   *MPC860_SPMODE(pSpi->regBase) = DisSPI;
 
   /* Set up for "write enable latch (enable write operations)". */
   *eep_wt_ptr = 6;
 
   /* Set up transmit buffer descriptor. */
   pSpi->pTxBdBase->dataPointer = eep_wt_ptr;
   pSpi->pTxBdBase->dataLength = 1;
   pSpi->pTxBdBase->statusMode = ( SPI_TRANS_TX_BD_READY |
                                   SPI_TRANS_TX_BD_WRAP  |
                                   SPI_TRANS_TX_BD_LAST );
 
   /* Set SPI read value. */
   pSpi->pPram->mrblr = 1;
 
   /* Set up receive buffer descriptor. */
   pSpi->pRxBdBase->dataPointer = eep_wt_ptr + 16;
   pSpi->pRxBdBase->statusMode = ( SPI_TRANS_RX_BD_EMPTY |
                                   SPI_TRANS_RX_BD_WRAP );
 
   /* Assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) &= 0x3FFFE;
 
   /* Enable SPI. */
   *MPC860_SPMODE(pSpi->regBase) = EnSPI;
 
   /* Start transfer. */
   *MPC860_SPCOM(pSpi->regBase) = SPI_STR;
 
   /* Wait for reading to finish. */
   while (pSpi->pRxBdBase->statusMode & 0x8000)
     {
       /* Busy-wait. */
       ;
     }
 
   /* De-assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) |= 0x00001;
 
   return;
 }	/* end of sysNvRamWriteEnable */
 
 
 /******************************************************************************
 *
 * sysNvRamWriteByte - write a byte to NVRAM
 *
 * This routine writes one byte to NVRAM
 *
 * RETURNS: none
 *
 * NOMANUAL
 */
 
 LOCAL void	sysNvRamWriteByte(
                               UCHAR		data,
                               USHORT		eep_addr)
 {
   SPI_DEV*	pSpi;
 
 
   pSpi = &spiDev;
 
   /* Wait for EEPROM to become ready. */
   while (sysNvRamGetStatus() == ERROR)
     {
       /* Busy-wait. */
       ;
     }
 
   /* Wait for transmit to finish (first). */
   while (pSpi->pTxBdBase->statusMode & SPI_TRANS_TX_BD_READY)
     {
       /* Busy-wait. */
       ;
     }
 
   /* Disable SPI (serial port interface). */
   *MPC860_SPMODE(pSpi->regBase) = DisSPI;
 
 
   /* Set up for "write data to memory array beginning at selected addr". */
   *eep_wt_ptr = 2;
 
   /* Write the given character into the proper write buffer location. */
   *(eep_wt_ptr + 3) = data;
 
   *(USHORT*) (eep_wt_ptr + 1) = eep_addr;
 
   /* Set up transmit buffer descriptor. */
   pSpi->pTxBdBase->dataPointer = eep_wt_ptr;
   pSpi->pTxBdBase->dataLength = 4;
   pSpi->pTxBdBase->statusMode =  ( SPI_TRANS_TX_BD_READY |
                                    SPI_TRANS_TX_BD_WRAP  |
                                    SPI_TRANS_TX_BD_LAST );
 
   /* Set SPI read value. */
   pSpi->pPram->mrblr = 4;
 
   /* Set up receive buffer descriptor. */
   pSpi->pRxBdBase->dataPointer = eep_wt_ptr + 32;
   pSpi->pRxBdBase->statusMode = ( SPI_TRANS_RX_BD_WRAP  |
                                   SPI_TRANS_RX_BD_EMPTY );
   /* Assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) &= 0x3FFFE;
 
   /* Enable SPI. */
   *MPC860_SPMODE(pSpi->regBase) = EnSPI;
 
   /* Start transfer. */
   *MPC860_SPCOM(pSpi->regBase) = SPI_STR;
 
   /* Wait for reading to finish. */
   while (pSpi->pRxBdBase->statusMode & SPI_TRANS_RX_BD_EMPTY)
     {
       /* Busy-wait. */
       ;
     }
 
   /* De-assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) |= 0x00001;
 
   return;
 }	/* end of sysNvRamWriteByte */
 
 
 /******************************************************************************
 *
 * sysNvRamGetStatus - get the status of NVRAM
 *
 * This routine gets the status of the NVRAM
 *
 * RETURNS: OK or ERROR
 *
 * NOMANUAL
 */
 
 LOCAL STATUS	sysNvRamGetStatus(
                                   void)
 {
   SPI_DEV*	pSpi;
 
 
   pSpi = &spiDev;
 
   /* Wait for transmit to finish (first). */
   while (pSpi->pTxBdBase->statusMode & SPI_TRANS_TX_BD_READY)
     {
       /* Busy-wait. */
       ;
     }
 
   /* Assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) &= 0x3FFFE;
 
   /* Disable SPI (serial port interface). */
   *MPC860_SPMODE(pSpi->regBase) = DisSPI;
 
   /* Set up for "read status register". */
   *eep_wt_ptr = 5;
 
   /* Set up transmit buffer descriptor. */
   pSpi->pTxBdBase->dataPointer = eep_wt_ptr;
   pSpi->pTxBdBase->dataLength = 2;
   pSpi->pTxBdBase->statusMode = ( SPI_TRANS_TX_BD_READY |
                                   SPI_TRANS_TX_BD_WRAP  |
                                   SPI_TRANS_TX_BD_LAST );
 
   /* Set SPI read value. */
   pSpi->pPram->mrblr = 2;
 
   /* Set up receive buffer descriptor. */
   pSpi->pRxBdBase->dataPointer = eep_wt_ptr + 16;
   pSpi->pRxBdBase->statusMode = ( SPI_TRANS_RX_BD_WRAP  |
                                   SPI_TRANS_RX_BD_EMPTY );
 
   /* Enable SPI. */
   *MPC860_SPMODE(pSpi->regBase) = EnSPI;
 
   /* Start transfer. */
   *MPC860_SPCOM(pSpi->regBase) = SPI_STR;
 
   /* Wait for reading to finish. */
   while (pSpi->pRxBdBase->statusMode & SPI_TRANS_RX_BD_EMPTY)
     {
       ;
     }
 
   /* De-assert EEPROM chip select (CS). */
   *PBDAT(pSpi->regBase) |= 0x00001;
 
   if (*(eep_wt_ptr + 17) & 1)
     {
       return(ERROR);
     }
   else
     {
       return(OK);
     }
 }	/* end of sysNvRamGetStatus */
 
 
 
 /* NV-RAM test. */
 UCHAR	read_from_EEPROM[(SPI_SERIAL_EEPROM_SZ + SPI_SERIAL_CMD_SEQ_SZ)];
 UCHAR	write_to_EEPROM[(SPI_SERIAL_EEPROM_SZ + SPI_SERIAL_CMD_SEQ_SZ)];
 void	nvram_test(int seed,int offset )
 {
   STATUS	status;
   int		i;
 
 
   printf("About to init SPI.\n");
   sysHwSpiInit();
   printf("About to read contents of entire EEPROM.\n");
   status = sysNvRamGet(&read_from_EEPROM[0], SPI_SERIAL_EEPROM_SZ, 0);
   printf("Status of sysNvRamGet is %d.\n", status);
   printf("Contents of EEPROM are: \n");
   for (i = 0; i < 64; i++)
     {
       printf("\n%x %x %x %x",
              *((UINT*) &read_from_EEPROM[i * 16]),
              *((UINT*) &read_from_EEPROM[(i * 16) + 4]),
              *((UINT*) &read_from_EEPROM[(i * 16) + 8]),
              *((UINT*) &read_from_EEPROM[(i * 16) + 12]));
     }
   for (i = 0; i < SPI_SERIAL_EEPROM_SZ; i++)
     {
       write_to_EEPROM[i] = (unsigned char)0;
     }
   printf("About to write contents of entire EEPROM.\n");
 	status = sysNvRamSet(&write_to_EEPROM[0], SPI_SERIAL_EEPROM_SZ - offset,
 							offset);
   printf("Status of sysNvRamSet is %d.\n", status);
   printf("About to read contents of entire EEPROM.\n");
   status = sysNvRamGet(&read_from_EEPROM[0], SPI_SERIAL_EEPROM_SZ, 0);
 
 	for (i = 0; i < SPI_SERIAL_EEPROM_SZ; i++)
 		{
 		if (read_from_EEPROM[i] != write_to_EEPROM[i])
 			{
 			printf("\n%d: 0x%02x != 0x%02x ", i, read_from_EEPROM[i],
 					write_to_EEPROM[i]);
 			}
 		}
   printf("\nDONE");
     
   return;
 }
 
 
 /* end of sysSpiNvRam.c */