board/ip860/flash.c - filogic/uboot - Gitiles

 /*
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * 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 program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * 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., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 #include <common.h>
 #include <mpc8xx.h>

 flash_info_t	flash_info[CFG_MAX_FLASH_BANKS]; /* info for FLASH chips	*/

 #if defined(CONFIG_ENV_IS_IN_FLASH)
 # ifndef  CFG_ENV_ADDR
 #  define CFG_ENV_ADDR	(CFG_FLASH_BASE + CFG_ENV_OFFSET)
 # endif
 # ifndef  CFG_ENV_SIZE
 #  define CFG_ENV_SIZE	CFG_ENV_SECT_SIZE
 # endif
 # ifndef  CFG_ENV_SECT_SIZE
 #  define CFG_ENV_SECT_SIZE  CFG_ENV_SIZE
 # endif
 #endif

 /*-----------------------------------------------------------------------
  * Functions
  */
 static ulong flash_get_size (vu_long *addr, flash_info_t *info);
 static int write_word (flash_info_t *info, ulong dest, ulong data);
 static void flash_get_offsets (ulong base, flash_info_t *info);

 /*-----------------------------------------------------------------------
  */

 unsigned long flash_init (void)
 {
 	volatile immap_t	*immap  = (immap_t *)CFG_IMMR;
 	volatile memctl8xx_t	*memctl = &immap->im_memctl;
 	volatile ip860_bcsr_t	*bcsr   = (ip860_bcsr_t *)BCSR_BASE;
 	unsigned long size;
 	int i;

 	/* Init: enable write,
 	 * or we cannot even write flash commands
 	 */
 	bcsr->bd_ctrl |= BD_CTRL_FLWE;

 	for (i=0; i<CFG_MAX_FLASH_BANKS; ++i) {
 		flash_info[i].flash_id = FLASH_UNKNOWN;
 	}

 	/* Static FLASH Bank configuration here - FIXME XXX */

 	size = flash_get_size((vu_long *)FLASH_BASE, &flash_info[0]);

 	if (flash_info[0].flash_id == FLASH_UNKNOWN) {
 		printf ("## Unknown FLASH on Bank 0 - Size = 0x%08lx = %ld MB\n",
 			size, size<<20);
 	}

 	/* Remap FLASH according to real size */
 	memctl->memc_or1 = CFG_OR_TIMING_FLASH | (-size & 0xFFFF8000);
 	memctl->memc_br1 = (CFG_FLASH_BASE & BR_BA_MSK) |
 				(memctl->memc_br1 & ~(BR_BA_MSK));

 	/* Re-do sizing to get full correct info */
 	size = flash_get_size((vu_long *)CFG_FLASH_BASE, &flash_info[0]);

 	flash_get_offsets (CFG_FLASH_BASE, &flash_info[0]);

 	flash_info[0].size = size;

 #if CFG_MONITOR_BASE >= CFG_FLASH_BASE
 	/* monitor protection ON by default */
 	flash_protect(FLAG_PROTECT_SET,
 		      CFG_MONITOR_BASE,
 		      CFG_MONITOR_BASE+monitor_flash_len-1,
 		      &flash_info[0]);
 #endif

 #ifdef	CONFIG_ENV_IS_IN_FLASH
 	/* ENV protection ON by default */
 	flash_protect(FLAG_PROTECT_SET,
 		      CFG_ENV_ADDR,
 		      CFG_ENV_ADDR+CFG_ENV_SECT_SIZE-1,
 		      &flash_info[0]);
 #endif
 	return (size);
 }

 /*-----------------------------------------------------------------------
  */
 static void flash_get_offsets (ulong base, flash_info_t *info)
 {
 	int i;

 	/* all possible flash types
 	 * (28F016SV, 28F160S3, 28F320S3)
 	 * have the same erase block size: 64 kB per chip,
 	 * of 128 kB per bank
 	 */

 	/* set up sector start address table */
 	for (i = 0; i < info->sector_count; i++) {
 		info->start[i] = base;
 		base += 0x00020000;
 	}
 }

 /*-----------------------------------------------------------------------
  */
 void flash_print_info  (flash_info_t *info)
 {
 	int i;

 	if (info->flash_id == FLASH_UNKNOWN) {
 		printf ("missing or unknown FLASH type\n");
 		return;
 	}

 	switch (info->flash_id & FLASH_VENDMASK) {
 	case FLASH_MAN_INTEL:	printf ("Intel ");		break;
 	default:		printf ("Unknown Vendor ");	break;
 	}

 	switch (info->flash_id & FLASH_TYPEMASK) {
 	case FLASH_28F016SV:	printf ("28F016SV (16 Mbit, 32 x 64k)\n");
 				break;
 	case FLASH_28F160S3:	printf ("28F160S3 (16 Mbit, 32 x 512K)\n");
 				break;
 	case FLASH_28F320S3:	printf ("28F320S3 (32 Mbit, 64 x 512K)\n");
 				break;
 	default:		printf ("Unknown Chip Type\n");
 				break;
 	}

 	printf ("  Size: %ld MB in %d Sectors\n",
 		info->size >> 20, info->sector_count);

 	printf ("  Sector Start Addresses:");
 	for (i=0; i<info->sector_count; ++i) {
 		if ((i % 5) == 0)
 			printf ("\n   ");
 		printf (" %08lX%s",
 			info->start[i],
 			info->protect[i] ? " (RO)" : "     "
 		);
 	}
 	printf ("\n");
 	return;
 }

 /*-----------------------------------------------------------------------
  */


 /*-----------------------------------------------------------------------
  */

 /*
  * The following code cannot be run from FLASH!
  */

 static ulong flash_get_size (vu_long *addr, flash_info_t *info)
 {
 	short i;
 	ulong value;
 	ulong base = (ulong)addr;

 	/* Write "Intelligent Identifier" command: read Manufacturer ID */
 	*addr = 0x90909090;

 	value = addr[0];
 	switch (value) {
 	case (MT_MANUFACT & 0x00FF00FF):	/* MT or => Intel */
 	case (INTEL_ALT_MANU & 0x00FF00FF):
 		info->flash_id = FLASH_MAN_INTEL;
 		break;
 	default:
 		info->flash_id = FLASH_UNKNOWN;
 		info->sector_count = 0;
 		info->size = 0;
 		return (0);			/* no or unknown flash	*/
 	}

 	value = addr[1];			/* device ID		*/

 	switch (value) {
 	case (INTEL_ID_28F016S):
 		info->flash_id += FLASH_28F016SV;
 		info->sector_count = 32;
 		info->size = 0x00400000;
 		break;				/* => 2x2 MB		*/

 	case (INTEL_ID_28F160S3):
 		info->flash_id += FLASH_28F160S3;
 		info->sector_count = 32;
 		info->size = 0x00400000;
 		break;				/* => 2x2 MB		*/

 	case (INTEL_ID_28F320S3):
 		info->flash_id += FLASH_28F320S3;
 		info->sector_count = 64;
 		info->size = 0x00800000;
 		break;				/* => 2x4 MB		*/

 	default:
 		info->flash_id = FLASH_UNKNOWN;
 		return (0);			/* => no or unknown flash */

 	}

 	/* set up sector start address table */
 	for (i = 0; i < info->sector_count; i++) {
 		info->start[i] = base + (i * 0x00020000);
 		/* don't know how to check sector protection */
 		info->protect[i] = 0;
 	}

 	/*
 	 * Prevent writes to uninitialized FLASH.
 	 */
 	if (info->flash_id != FLASH_UNKNOWN) {
 		addr = (vu_long *)info->start[0];

 		*addr = 0xFFFFFF;	/* reset bank to read array mode */
 	}

 	return (info->size);
 }


 /*-----------------------------------------------------------------------
  */

 int	flash_erase (flash_info_t *info, int s_first, int s_last)
 {
 	int flag, prot, sect;
 	ulong start, now, last;

 	if ((s_first < 0) || (s_first > s_last)) {
 		if (info->flash_id == FLASH_UNKNOWN) {
 			printf ("- missing\n");
 		} else {
 			printf ("- no sectors to erase\n");
 		}
 		return 1;
 	}

 	if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_INTEL) {
 		printf ("Can't erase unknown flash type %08lx - aborted\n",
 			info->flash_id);
 		return 1;
 	}

 	prot = 0;
 	for (sect=s_first; sect<=s_last; ++sect) {
 		if (info->protect[sect]) {
 			prot++;
 		}
 	}

 	if (prot) {
 		printf ("- Warning: %d protected sectors will not be erased!\n",
 			prot);
 	} else {
 		printf ("\n");
 	}

 	start = get_timer (0);
 	last  = start;

 	/* Start erase on unprotected sectors */
 	for (sect = s_first; sect<=s_last; sect++) {
 		if (info->protect[sect] == 0) {	/* not protected */
 			vu_long *addr = (vu_long *)(info->start[sect]);

 			/* Disable interrupts which might cause a timeout here */
 			flag = disable_interrupts();

 			/* Single Block Erase Command */
 			*addr = 0x20202020;
 			/* Confirm */
 			*addr = 0xD0D0D0D0;
 			/* Resume Command, as per errata update */
 			*addr = 0xD0D0D0D0;

 			/* re-enable interrupts if necessary */
 			if (flag)
 				enable_interrupts();

 			/* wait at least 80us - let's wait 1 ms */
 			udelay (1000);

 			while ((*addr & 0x00800080) != 0x00800080) {
 				if ((now=get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
 					printf ("Timeout\n");
 					*addr = 0xFFFFFFFF;	/* reset bank */
 					return 1;
 				}
 				/* show that we're waiting */
 				if ((now - last) > 1000) {	/* every second */
 					putc ('.');
 					last = now;
 				}
 			}

 			/* reset to read mode */
 			*addr = 0xFFFFFFFF;
 		}
 	}

 	printf (" done\n");
 	return 0;
 }

 /*-----------------------------------------------------------------------
  * Copy memory to flash, returns:
  * 0 - OK
  * 1 - write timeout
  * 2 - Flash not erased
  */

 int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
 {
 	ulong cp, wp, data;
 	int i, l, rc;

 	wp = (addr & ~3);	/* get lower word aligned address */

 	/*
 	 * handle unaligned start bytes
 	 */
 	if ((l = addr - wp) != 0) {
 		data = 0;
 		for (i=0, cp=wp; i<l; ++i, ++cp) {
 			data = (data << 8) | (*(uchar *)cp);
 		}
 		for (; i<4 && cnt>0; ++i) {
 			data = (data << 8) | *src++;
 			--cnt;
 			++cp;
 		}
 		for (; cnt==0 && i<4; ++i, ++cp) {
 			data = (data << 8) | (*(uchar *)cp);
 		}

 		if ((rc = write_word(info, wp, data)) != 0) {
 			return (rc);
 		}
 		wp += 4;
 	}

 	/*
 	 * handle word aligned part
 	 */
 	while (cnt >= 4) {
 		data = 0;
 		for (i=0; i<4; ++i) {
 			data = (data << 8) | *src++;
 		}
 		if ((rc = write_word(info, wp, data)) != 0) {
 			return (rc);
 		}
 		wp  += 4;
 		cnt -= 4;
 	}

 	if (cnt == 0) {
 		return (0);
 	}

 	/*
 	 * handle unaligned tail bytes
 	 */
 	data = 0;
 	for (i=0, cp=wp; i<4 && cnt>0; ++i, ++cp) {
 		data = (data << 8) | *src++;
 		--cnt;
 	}
 	for (; i<4; ++i, ++cp) {
 		data = (data << 8) | (*(uchar *)cp);
 	}

 	return (write_word(info, wp, data));
 }

 /*-----------------------------------------------------------------------
  * Write a word to Flash, returns:
  * 0 - OK
  * 1 - write timeout
  * 2 - Flash not erased
  */
 static int write_word (flash_info_t *info, ulong dest, ulong data)
 {
 	vu_long *addr = (vu_long *)dest;
 	ulong start, csr;
 	int flag;

 	/* Check if Flash is (sufficiently) erased */
 	if ((*addr & data) != data) {
 		return (2);
 	}
 	/* Disable interrupts which might cause a timeout here */
 	flag = disable_interrupts();

 	/* Write Command */
 	*addr = 0x10101010;

 	/* Write Data */
 	*addr = data;

 	/* re-enable interrupts if necessary */
 	if (flag)
 		enable_interrupts();

 	/* data polling for D7 */
 	start = get_timer (0);
 	flag  = 0;
 	while (((csr = *addr) & 0x00800080) != 0x00800080) {
 		if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
 			flag = 1;
 			break;
 		}
 	}
 	if (csr & 0x00400040) {
 printf ("CSR indicates write error (%08lx) at %08lx\n", csr, (ulong)addr);
 		flag = 1;
 	}

 	/* Clear Status Registers Command */
 	*addr = 0x50505050;
 	/* Reset to read array mode */
 	*addr = 0xFFFFFFFF;

 	return (flag);
 }

 /*-----------------------------------------------------------------------
  */
	/*
	* (C) Copyright 2000
	* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* 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 program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* 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., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	#include <common.h>
	#include <mpc8xx.h>

	flash_info_t flash_info[CFG_MAX_FLASH_BANKS]; /* info for FLASH chips */

	#if defined(CONFIG_ENV_IS_IN_FLASH)
	# ifndef CFG_ENV_ADDR
	# define CFG_ENV_ADDR (CFG_FLASH_BASE + CFG_ENV_OFFSET)
	# endif
	# ifndef CFG_ENV_SIZE
	# define CFG_ENV_SIZE CFG_ENV_SECT_SIZE
	# endif
	# ifndef CFG_ENV_SECT_SIZE
	# define CFG_ENV_SECT_SIZE CFG_ENV_SIZE
	# endif
	#endif

	/*-----------------------------------------------------------------------
	* Functions
	*/
	static ulong flash_get_size (vu_long addr, flash_info_t info);
	static int write_word (flash_info_t *info, ulong dest, ulong data);
	static void flash_get_offsets (ulong base, flash_info_t *info);

	/*-----------------------------------------------------------------------
	*/

	unsigned long flash_init (void)
	{
	volatile immap_t immap = (immap_t )CFG_IMMR;
	volatile memctl8xx_t *memctl = &immap->im_memctl;
	volatile ip860_bcsr_t bcsr = (ip860_bcsr_t )BCSR_BASE;
	unsigned long size;
	int i;

	/* Init: enable write,
	* or we cannot even write flash commands
	*/
	bcsr->bd_ctrl \|= BD_CTRL_FLWE;

	for (i=0; i<CFG_MAX_FLASH_BANKS; ++i) {
	flash_info[i].flash_id = FLASH_UNKNOWN;
	}

	/* Static FLASH Bank configuration here - FIXME XXX */

	size = flash_get_size((vu_long *)FLASH_BASE, &flash_info[0]);

	if (flash_info[0].flash_id == FLASH_UNKNOWN) {
	printf ("## Unknown FLASH on Bank 0 - Size = 0x%08lx = %ld MB\n",
	size, size<<20);
	}

	/* Remap FLASH according to real size */
	memctl->memc_or1 = CFG_OR_TIMING_FLASH \| (-size & 0xFFFF8000);
	memctl->memc_br1 = (CFG_FLASH_BASE & BR_BA_MSK) \|
	(memctl->memc_br1 & ~(BR_BA_MSK));

	/* Re-do sizing to get full correct info */
	size = flash_get_size((vu_long *)CFG_FLASH_BASE, &flash_info[0]);

	flash_get_offsets (CFG_FLASH_BASE, &flash_info[0]);

	flash_info[0].size = size;

	#if CFG_MONITOR_BASE >= CFG_FLASH_BASE
	/* monitor protection ON by default */
	flash_protect(FLAG_PROTECT_SET,
	CFG_MONITOR_BASE,
	CFG_MONITOR_BASE+monitor_flash_len-1,
	&flash_info[0]);
	#endif

	#ifdef CONFIG_ENV_IS_IN_FLASH
	/* ENV protection ON by default */
	flash_protect(FLAG_PROTECT_SET,
	CFG_ENV_ADDR,
	CFG_ENV_ADDR+CFG_ENV_SECT_SIZE-1,
	&flash_info[0]);
	#endif
	return (size);
	}

	/*-----------------------------------------------------------------------
	*/
	static void flash_get_offsets (ulong base, flash_info_t *info)
	{
	int i;

	/* all possible flash types
	* (28F016SV, 28F160S3, 28F320S3)
	* have the same erase block size: 64 kB per chip,
	* of 128 kB per bank
	*/

	/* set up sector start address table */
	for (i = 0; i < info->sector_count; i++) {
	info->start[i] = base;
	base += 0x00020000;
	}
	}

	/*-----------------------------------------------------------------------
	*/
	void flash_print_info (flash_info_t *info)
	{
	int i;

	if (info->flash_id == FLASH_UNKNOWN) {
	printf ("missing or unknown FLASH type\n");
	return;
	}

	switch (info->flash_id & FLASH_VENDMASK) {
	case FLASH_MAN_INTEL: printf ("Intel "); break;
	default: printf ("Unknown Vendor "); break;
	}

	switch (info->flash_id & FLASH_TYPEMASK) {
	case FLASH_28F016SV: printf ("28F016SV (16 Mbit, 32 x 64k)\n");
	break;
	case FLASH_28F160S3: printf ("28F160S3 (16 Mbit, 32 x 512K)\n");
	break;
	case FLASH_28F320S3: printf ("28F320S3 (32 Mbit, 64 x 512K)\n");
	break;
	default: printf ("Unknown Chip Type\n");
	break;
	}

	printf (" Size: %ld MB in %d Sectors\n",
	info->size >> 20, info->sector_count);

	printf (" Sector Start Addresses:");
	for (i=0; i<info->sector_count; ++i) {
	if ((i % 5) == 0)
	printf ("\n ");
	printf (" %08lX%s",
	info->start[i],
	info->protect[i] ? " (RO)" : " "
	);
	}
	printf ("\n");
	return;
	}

	/*-----------------------------------------------------------------------
	*/


	/*-----------------------------------------------------------------------
	*/

	/*
	* The following code cannot be run from FLASH!
	*/

	static ulong flash_get_size (vu_long addr, flash_info_t info)
	{
	short i;
	ulong value;
	ulong base = (ulong)addr;

	/* Write "Intelligent Identifier" command: read Manufacturer ID */
	*addr = 0x90909090;

	value = addr[0];
	switch (value) {
	case (MT_MANUFACT & 0x00FF00FF): /* MT or => Intel */
	case (INTEL_ALT_MANU & 0x00FF00FF):
	info->flash_id = FLASH_MAN_INTEL;
	break;
	default:
	info->flash_id = FLASH_UNKNOWN;
	info->sector_count = 0;
	info->size = 0;
	return (0); /* no or unknown flash */
	}

	value = addr[1]; /* device ID */

	switch (value) {
	case (INTEL_ID_28F016S):
	info->flash_id += FLASH_28F016SV;
	info->sector_count = 32;
	info->size = 0x00400000;
	break; /* => 2x2 MB */

	case (INTEL_ID_28F160S3):
	info->flash_id += FLASH_28F160S3;
	info->sector_count = 32;
	info->size = 0x00400000;
	break; /* => 2x2 MB */

	case (INTEL_ID_28F320S3):
	info->flash_id += FLASH_28F320S3;
	info->sector_count = 64;
	info->size = 0x00800000;
	break; /* => 2x4 MB */

	default:
	info->flash_id = FLASH_UNKNOWN;
	return (0); /* => no or unknown flash */

	}

	/* set up sector start address table */
	for (i = 0; i < info->sector_count; i++) {
	info->start[i] = base + (i * 0x00020000);
	/* don't know how to check sector protection */
	info->protect[i] = 0;
	}

	/*
	* Prevent writes to uninitialized FLASH.
	*/
	if (info->flash_id != FLASH_UNKNOWN) {
	addr = (vu_long *)info->start[0];

	addr = 0xFFFFFF; / reset bank to read array mode */
	}

	return (info->size);
	}


	/*-----------------------------------------------------------------------
	*/

	int flash_erase (flash_info_t *info, int s_first, int s_last)
	{
	int flag, prot, sect;
	ulong start, now, last;

	if ((s_first < 0) \|\| (s_first > s_last)) {
	if (info->flash_id == FLASH_UNKNOWN) {
	printf ("- missing\n");
	} else {
	printf ("- no sectors to erase\n");
	}
	return 1;
	}

	if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_INTEL) {
	printf ("Can't erase unknown flash type %08lx - aborted\n",
	info->flash_id);
	return 1;
	}

	prot = 0;
	for (sect=s_first; sect<=s_last; ++sect) {
	if (info->protect[sect]) {
	prot++;
	}
	}

	if (prot) {
	printf ("- Warning: %d protected sectors will not be erased!\n",
	prot);
	} else {
	printf ("\n");
	}

	start = get_timer (0);
	last = start;

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
	if (info->protect[sect] == 0) { /* not protected */
	vu_long addr = (vu_long )(info->start[sect]);

	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	/* Single Block Erase Command */
	*addr = 0x20202020;
	/* Confirm */
	*addr = 0xD0D0D0D0;
	/* Resume Command, as per errata update */
	*addr = 0xD0D0D0D0;

	/* re-enable interrupts if necessary */
	if (flag)
	enable_interrupts();

	/* wait at least 80us - let's wait 1 ms */
	udelay (1000);

	while ((*addr & 0x00800080) != 0x00800080) {
	if ((now=get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
	printf ("Timeout\n");
	addr = 0xFFFFFFFF; / reset bank */
	return 1;
	}
	/* show that we're waiting */
	if ((now - last) > 1000) { /* every second */
	putc ('.');
	last = now;
	}
	}

	/* reset to read mode */
	*addr = 0xFFFFFFFF;
	}
	}

	printf (" done\n");
	return 0;
	}

	/*-----------------------------------------------------------------------
	* Copy memory to flash, returns:
	* 0 - OK
	* 1 - write timeout
	* 2 - Flash not erased
	*/

	int write_buff (flash_info_t info, uchar src, ulong addr, ulong cnt)
	{
	ulong cp, wp, data;
	int i, l, rc;

	wp = (addr & ~3); /* get lower word aligned address */

	/*
	* handle unaligned start bytes
	*/
	if ((l = addr - wp) != 0) {
	data = 0;
	for (i=0, cp=wp; i<l; ++i, ++cp) {
	data = (data << 8) \| ((uchar )cp);
	}
	for (; i<4 && cnt>0; ++i) {
	data = (data << 8) \| *src++;
	--cnt;
	++cp;
	}
	for (; cnt==0 && i<4; ++i, ++cp) {
	data = (data << 8) \| ((uchar )cp);
	}

	if ((rc = write_word(info, wp, data)) != 0) {
	return (rc);
	}
	wp += 4;
	}

	/*
	* handle word aligned part
	*/
	while (cnt >= 4) {
	data = 0;
	for (i=0; i<4; ++i) {
	data = (data << 8) \| *src++;
	}
	if ((rc = write_word(info, wp, data)) != 0) {
	return (rc);
	}
	wp += 4;
	cnt -= 4;
	}

	if (cnt == 0) {
	return (0);
	}

	/*
	* handle unaligned tail bytes
	*/
	data = 0;
	for (i=0, cp=wp; i<4 && cnt>0; ++i, ++cp) {
	data = (data << 8) \| *src++;
	--cnt;
	}
	for (; i<4; ++i, ++cp) {
	data = (data << 8) \| ((uchar )cp);
	}

	return (write_word(info, wp, data));
	}

	/*-----------------------------------------------------------------------
	* Write a word to Flash, returns:
	* 0 - OK
	* 1 - write timeout
	* 2 - Flash not erased
	*/
	static int write_word (flash_info_t *info, ulong dest, ulong data)
	{
	vu_long addr = (vu_long )dest;
	ulong start, csr;
	int flag;

	/* Check if Flash is (sufficiently) erased */
	if ((*addr & data) != data) {
	return (2);
	}
	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	/* Write Command */
	*addr = 0x10101010;

	/* Write Data */
	*addr = data;

	/* re-enable interrupts if necessary */
	if (flag)
	enable_interrupts();

	/* data polling for D7 */
	start = get_timer (0);
	flag = 0;
	while (((csr = *addr) & 0x00800080) != 0x00800080) {
	if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
	flag = 1;
	break;
	}
	}
	if (csr & 0x00400040) {
	printf ("CSR indicates write error (%08lx) at %08lx\n", csr, (ulong)addr);
	flag = 1;
	}

	/* Clear Status Registers Command */
	*addr = 0x50505050;
	/* Reset to read array mode */
	*addr = 0xFFFFFFFF;

	return (flag);
	}

	/*-----------------------------------------------------------------------
	*/