flash_amd.c

针对德州仪器DM270开发板的bootloader,其实现了内核的下载以及文件系统的下载

/*
 * File: flash_amd.c
 *
 * An implementation of a flash utility specific to the AMD chipset
 * (AM29L640D). This implementation, while vendor dependent, exposes
 * the vendor independent flash.h interface allowing it to plug generically
 * into the bootloader. Please see flash.h for more info.
 *
 * See Also
 *    flash.h
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS  PROVIDED  ``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   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT,  INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include "flash.h"
#include "types.h"
#include "util.h"
#include "io.h"
#include "memconfig.h"

#define NUM_CHIP_SECT 128
#define NUM_CHIPS 1
#define TOTAL_SECT (NUM_CHIPS*NUM_CHIP_SECT)

// 128 sectors per AMD Am29LV640D (8 MBytes total bytes)
static const int sect_sizes[NUM_CHIP_SECT] = {
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000,
  0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000, 0x10000
};

typedef struct {
  int start_addr;
  int end_addr;
} sect_info_t;

sect_info_t sect_info[TOTAL_SECT];

void WagTheDog(void)
{
  int i;

  for (i = 0; i < 100; i++);
}

void WaitForFlashEraseToStart( void )
{
    enum constants { _DQ3 = 0x08 };
    unsigned short * addr = (unsigned short *)BSPCONF_FLASH_BASE;
    
    while (1)
    {
	
	if (addr[0] & _DQ3)
	{
	    break;
	}
	
	// Operation could take a while
	WagTheDog();
    }

}

unsigned char IsFlashOperationSuccessful( unsigned short * flashAddress )
{
    enum constants { _DQ6 = 0x40, _DQ5 = 0x20 };
    
    volatile unsigned int toggleCheck;
    volatile unsigned int previousToggleCheck;
    
    previousToggleCheck = flashAddress[0];
    
    while (1)
    {
	
	toggleCheck = flashAddress[0];
	
	// Is the flash operation still going? (DQ6 toggling)
	if (!((previousToggleCheck & _DQ6) ^ (toggleCheck & _DQ6)))
	{
	    // If DQ6 isn't toggling the flash operation is complete
	    return 1;
	}
	else
	{
	    // If DQ6 is toggling the operation is not done yet
	    
	    // Has the flash operation timed out? (DQ5 == 1)
	    if (toggleCheck & _DQ5)
	    {
		// If DQ5 is set, the operation has timed out
		
		// Make one more check to see if the operation is complete
		previousToggleCheck = flashAddress[0];
		toggleCheck = flashAddress[0];
		
		if (!((previousToggleCheck & _DQ6) ^ (toggleCheck & _DQ6)))
		{
		    // If DQ6 isn't toggling the flash operation is complete
		    return 1;
		}
		else
		{
		    // If DQ6 is still toggling, an error has occured
		    return 0;
		}
	    }
	}
	
	previousToggleCheck = toggleCheck;
	
	// Operation could take a while
	WagTheDog( );
    }
    
    // Can't get here
    return 0;
}

/******************************
 Routine:
 Description: Returns the starting address for flash block
              containing block_address
******************************/

unsigned short *get_start_address(unsigned short *block_address)
{
  int i;
  for (i=0; i<TOTAL_SECT; i++) {
    if (((unsigned short *)sect_info[i].start_addr >= block_address) &&
        ((unsigned short *)sect_info[i].start_addr <= block_address)) {
      return((unsigned short *)sect_info[i].start_addr);
    }
  } 
  return(0);
}

/******************************
 Routine:
 Description: Returns the ending address for flash block
              containing block_address
******************************/

unsigned short *get_end_address(unsigned short *block_address)
{
  int i;
  for (i=0; i<TOTAL_SECT; i++) {
    if (((unsigned short *)sect_info[i].start_addr >= block_address) &&
        ((unsigned short *)sect_info[i].start_addr <= block_address)) {
      return((unsigned short *)sect_info[i].end_addr);
    }
  }
  return(0);
}

/******************************
 Routine:
 Description: returns true if the block has been erased
******************************/
static int verify_block_erased(unsigned short *block_addr, int print_err)
{
  volatile unsigned short *addr;
  int err=false;
  volatile unsigned short contents;
  unsigned short *start_addr;
  unsigned short *end_addr;

  start_addr=get_start_address(block_addr);
  end_addr=get_end_address(block_addr);

  for (addr=start_addr; addr<end_addr; addr++) {
    contents = *addr;
    if (contents != 0xFFFF) { 
      err=true;
      break;
    }
  }
  if (err && print_err) {
    util_printf("Error: address range %X - %X not erased: %X=%x\n", 
		start_addr, end_addr, addr, contents);
  }
    return(!err);
}

#ifdef BSPCONF_BTLDR_MEMMAP_DEBUG

/******************************
 Routine:
 Description:
******************************/
static void enable_read_mode()
{
  volatile unsigned short *addr;
  addr = (unsigned short *) BSPCONF_FLASH_BASE;
  *addr = 0xF0;
  io_delay(1);
}

/******************************
 Routine:
 Description: Returns true if flash
 part supports CFI
******************************/
static int cfi_supported(void)
{
  volatile unsigned short *addr;
  int i,j;
  int read_array[3];

  addr = (unsigned short *) BSPCONF_FLASH_BASE;
  enable_read_mode();
  addr[0x55] = 0x98; /* Enter read array mode */
  j=0;
  for ( i=0x10; i <= 0x12; i++)
  {
    read_array[j++] = addr[i];
  }
  enable_read_mode();
  return( ( read_array[0] == 'Q' ) &&
          ( read_array[1] == 'R' ) &&
          ( read_array[2] == 'Y' ) );
}

/******************************
 Routine:
 Description: returns true if device
 code read, false if chip doesn't support CFI
******************************/
int read_device_codes(unsigned long *Code)
{
  unsigned short regval;
  volatile unsigned short *addr;
  addr = (unsigned short *) BSPCONF_FLASH_BASE;

  if ( ! cfi_supported() )
  {
    *Code=0;
    return(0);
  }
  enable_read_mode();
  addr[0x555] = 0xAA;
  addr[0x2AA] = 0x55;
  addr[0x555] = 0x90;
  regval = addr[0]; // mfg code.
  *Code = (regval<<16);
  regval = addr[1]; // device code.
  *Code = *Code | regval;
  enable_read_mode();
  return(1);
}

/******************************
 Routine:
 Description: returns true if chip supports CFI.  array elements
 from CFI_START_ADDR to CFI_END_ADDR filled with CFI read array data.
 Returns false if chip doesn't support CFI.
******************************/
int read_cfi_array(unsigned short array[], int array_size)
{
  volatile unsigned short *addr;