cmd_mem.c

/*
 * (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
 */

/*
 * Memory Functions
 *
 * Copied from FADS ROM, Dan Malek (dmalek@jlc.net)
 */

#include <common.h>
#include <command.h>
#ifdef CONFIG_HAS_DATAFLASH
#include <dataflash.h>
#endif
#include <watchdog.h>
#include <asm/io.h>
#include <linux/compiler.h>

DECLARE_GLOBAL_DATA_PTR;

static int mod_mem(cmd_tbl_t *, int, int, int, char * const []);

/* Display values from last command.
 * Memory modify remembered values are different from display memory.
 */
static uint	dp_last_addr, dp_last_size;
static uint	dp_last_length = 0x40;
static uint	mm_last_addr, mm_last_size;

static	ulong	base_address = 0;

/* Memory Display
 *
 * Syntax:
 *	md{.b, .w, .l} {addr} {len}
 */
#define DISP_LINE_LEN	16
static int do_mem_md(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong	addr, length;
#if defined(CONFIG_HAS_DATAFLASH)
	ulong	nbytes, linebytes;
#endif
	int	size;
	int rc = 0;

	/* We use the last specified parameters, unless new ones are
	 * entered.
	 */
	addr = dp_last_addr;
	size = dp_last_size;
	length = dp_last_length;

	if (argc < 2)
		return CMD_RET_USAGE;

	if ((flag & CMD_FLAG_REPEAT) == 0) {
		/* New command specified.  Check for a size specification.
		 * Defaults to long if no or incorrect specification.
		 */
		if ((size = cmd_get_data_size(argv[0], 4)) < 0)
			return 1;

		/* Address is specified since argc > 1
		*/
		addr = simple_strtoul(argv[1], NULL, 16);
		addr += base_address;

		/* If another parameter, it is the length to display.
		 * Length is the number of objects, not number of bytes.
		 */
		if (argc > 2)
			length = simple_strtoul(argv[2], NULL, 16);
	}

#if defined(CONFIG_HAS_DATAFLASH)
	/* Print the lines.
	 *
	 * We buffer all read data, so we can make sure data is read only
	 * once, and all accesses are with the specified bus width.
	 */
	nbytes = length * size;
	do {
		char	linebuf[DISP_LINE_LEN];
		void* p;
		linebytes = (nbytes>DISP_LINE_LEN)?DISP_LINE_LEN:nbytes;

		rc = read_dataflash(addr, (linebytes/size)*size, linebuf);
		p = (rc == DATAFLASH_OK) ? linebuf : (void*)addr;
		print_buffer(addr, p, size, linebytes/size, DISP_LINE_LEN/size);

		nbytes -= linebytes;
		addr += linebytes;
		if (ctrlc()) {
			rc = 1;
			break;
		}
	} while (nbytes > 0);
#else

# if defined(CONFIG_BLACKFIN)
	/* See if we're trying to display L1 inst */
	if (addr_bfin_on_chip_mem(addr)) {
		char linebuf[DISP_LINE_LEN];
		ulong linebytes, nbytes = length * size;
		do {
			linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;
			memcpy(linebuf, (void *)addr, linebytes);
			print_buffer(addr, linebuf, size, linebytes/size, DISP_LINE_LEN/size);

			nbytes -= linebytes;
			addr += linebytes;
			if (ctrlc()) {
				rc = 1;
				break;
			}
		} while (nbytes > 0);
	} else
# endif

	{
		ulong bytes = size * length;
		const void *buf = map_sysmem(addr, bytes);

		/* Print the lines. */
		print_buffer(addr, buf, size, length, DISP_LINE_LEN / size);
		addr += bytes;
		unmap_sysmem(buf);
	}
#endif

	dp_last_addr = addr;
	dp_last_length = length;
	dp_last_size = size;
	return (rc);
}

static int do_mem_mm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	return mod_mem (cmdtp, 1, flag, argc, argv);
}
static int do_mem_nm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	return mod_mem (cmdtp, 0, flag, argc, argv);
}

static int do_mem_mw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong	addr, writeval, count;
	int	size;
	void *buf;
	ulong bytes;

	if ((argc < 3) || (argc > 4))
		return CMD_RET_USAGE;

	/* Check for size specification.
	*/
	if ((size = cmd_get_data_size(argv[0], 4)) < 1)
		return 1;

	/* Address is specified since argc > 1
	*/
	addr = simple_strtoul(argv[1], NULL, 16);
	addr += base_address;

	/* Get the value to write.
	*/
	writeval = simple_strtoul(argv[2], NULL, 16);

	/* Count ? */
	if (argc == 4) {
		count = simple_strtoul(argv[3], NULL, 16);
	} else {
		count = 1;
	}

	bytes = size * count;
	buf = map_sysmem(addr, bytes);
	while (count-- > 0) {
		if (size == 4)
			*((ulong *)buf) = (ulong)writeval;
		else if (size == 2)
			*((ushort *)buf) = (ushort)writeval;
		else
			*((u_char *)buf) = (u_char)writeval;
		buf += size;
	}
	unmap_sysmem(buf);
	return 0;
}

#ifdef CONFIG_MX_CYCLIC
int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	int i;
	ulong count;

	if (argc < 4)
		return CMD_RET_USAGE;

	count = simple_strtoul(argv[3], NULL, 10);

	for (;;) {
		do_mem_md (NULL, 0, 3, argv);

		/* delay for <count> ms... */
		for (i=0; i<count; i++)
			udelay (1000);

		/* check for ctrl-c to abort... */
		if (ctrlc()) {
			puts("Abort\n");
			return 0;
		}
	}

	return 0;
}

int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	int i;
	ulong count;

	if (argc < 4)
		return CMD_RET_USAGE;

	count = simple_strtoul(argv[3], NULL, 10);

	for (;;) {
		do_mem_mw (NULL, 0, 3, argv);

		/* delay for <count> ms... */
		for (i=0; i<count; i++)
			udelay (1000);

		/* check for ctrl-c to abort... */
		if (ctrlc()) {
			puts("Abort\n");
			return 0;
		}
	}

	return 0;
}
#endif /* CONFIG_MX_CYCLIC */

static int do_mem_cmp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong	addr1, addr2, count, ngood, bytes;
	int	size;
	int     rcode = 0;
	const char *type;
	const void *buf1, *buf2, *base;

	if (argc != 4)
		return CMD_RET_USAGE;

	/* Check for size specification.
	*/
	if ((size = cmd_get_data_size(argv[0], 4)) < 0)
		return 1;
	type = size == 4 ? "word" : size == 2 ? "halfword" : "byte";

	addr1 = simple_strtoul(argv[1], NULL, 16);
	addr1 += base_address;

	addr2 = simple_strtoul(argv[2], NULL, 16);
	addr2 += base_address;

	count = simple_strtoul(argv[3], NULL, 16);

#ifdef CONFIG_HAS_DATAFLASH
	if (addr_dataflash(addr1) | addr_dataflash(addr2)){
		puts ("Comparison with DataFlash space not supported.\n\r");
		return 0;
	}
#endif

#ifdef CONFIG_BLACKFIN
	if (addr_bfin_on_chip_mem(addr1) || addr_bfin_on_chip_mem(addr2)) {
		puts ("Comparison with L1 instruction memory not supported.\n\r");
		return 0;
	}
#endif

	bytes = size * count;
	base = buf1 = map_sysmem(addr1, bytes);
	buf2 = map_sysmem(addr2, bytes);
	for (ngood = 0; ngood < count; ++ngood) {
		ulong word1, word2;
		if (size == 4) {
			word1 = *(ulong *)buf1;
			word2 = *(ulong *)buf2;
		} else if (size == 2) {
			word1 = *(ushort *)buf1;
			word2 = *(ushort *)buf2;
		} else {
			word1 = *(u_char *)buf1;
			word2 = *(u_char *)buf2;
		}
		if (word1 != word2) {
			ulong offset = buf1 - base;

			printf("%s at 0x%08lx (%#0*lx) != %s at 0x%08lx (%#0*lx)\n",
				type, (ulong)(addr1 + offset), size, word1,
				type, (ulong)(addr2 + offset), size, word2);
			rcode = 1;
			break;
		}

		buf1 += size;
		buf2 += size;

		/* reset watchdog from time to time */
		if ((ngood % (64 << 10)) == 0)
			WATCHDOG_RESET();
	}
	unmap_sysmem(buf1);
	unmap_sysmem(buf2);

	printf("Total of %ld %s(s) were the same\n", ngood, type);
	return rcode;
}

static int do_mem_cp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong	addr, dest, count, bytes;
	int	size;
	const void *src;
	void *buf;

	if (argc != 4)
		return CMD_RET_USAGE;

	/* Check for size specification.
	*/
	if ((size = cmd_get_data_size(argv[0], 4)) < 0)
		return 1;

	addr = simple_strtoul(argv[1], NULL, 16);
	addr += base_address;

	dest = simple_strtoul(argv[2], NULL, 16);
	dest += base_address;

	count = simple_strtoul(argv[3], NULL, 16);

	if (count == 0) {
		puts ("Zero length ???\n");
		return 1;
	}

#ifndef CONFIG_SYS_NO_FLASH
	/* check if we are copying to Flash */
	if ( (addr2info(dest) != NULL)
#ifdef CONFIG_HAS_DATAFLASH
	   && (!addr_dataflash(dest))
#endif
	   ) {
		int rc;

		puts ("Copy to Flash... ");

		rc = flash_write ((char *)addr, dest, count*size);
		if (rc != 0) {
			flash_perror (rc);
			return (1);
		}
		puts ("done\n");
		return 0;
	}
#endif

#ifdef CONFIG_HAS_DATAFLASH
	/* Check if we are copying from RAM or Flash to DataFlash */
	if (addr_dataflash(dest) && !addr_dataflash(addr)){
		int rc;

		puts ("Copy to DataFlash... ");

		rc = write_dataflash (dest, addr, count*size);

		if (rc != 1) {
			dataflash_perror (rc);
			return (1);
		}
		puts ("done\n");
		return 0;
	}

	/* Check if we are copying from DataFlash to RAM */
	if (addr_dataflash(addr) && !addr_dataflash(dest)
#ifndef CONFIG_SYS_NO_FLASH
				 && (addr2info(dest) == NULL)
#endif
	   ){
		int rc;
		rc = read_dataflash(addr, count * size, (char *) dest);
		if (rc != 1) {
			dataflash_perror (rc);
			return (1);
		}
		return 0;
	}

	if (addr_dataflash(addr) && addr_dataflash(dest)){
		puts ("Unsupported combination of source/destination.\n\r");
		return 1;
	}
#endif

#ifdef CONFIG_BLACKFIN
	/* See if we're copying to/from L1 inst */
	if (addr_bfin_on_chip_mem(dest) || addr_bfin_on_chip_mem(addr)) {
		memcpy((void *)dest, (void *)addr, count * size);
		return 0;
	}
#endif

	bytes = size * count;
	buf = map_sysmem(addr, bytes);
	src = map_sysmem(addr, bytes);
	while (count-- > 0) {
		if (size == 4)
			*((ulong *)buf) = *((ulong  *)src);
		else if (size == 2)
			*((ushort *)buf) = *((ushort *)src);
		else
			*((u_char *)buf) = *((u_char *)src);
		src += size;
		buf += size;

		/* reset watchdog from time to time */
		if ((count % (64 << 10)) == 0)
			WATCHDOG_RESET();
	}
	return 0;
}

static int do_mem_base(cmd_tbl_t *cmdtp, int flag, int argc,
		       char * const argv[])
{
	if (argc > 1) {
		/* Set new base address.
		*/
		base_address = simple_strtoul(argv[1], NULL, 16);
	}
	/* Print the current base address.
	*/
	printf("Base Address: 0x%08lx\n", base_address);
	return 0;
}

static int do_mem_loop(cmd_tbl_t *cmdtp, int flag, int argc,
		       char * const argv[])
{
	ulong	addr, length, i, bytes;
	int	size;
	volatile uint	*longp;
	volatile ushort *shortp;
	volatile u_char	*cp;
	const void *buf;

	if (argc < 3)
		return CMD_RET_USAGE;

	/*
	 * Check for a size specification.
	 * Defaults to long if no or incorrect specification.
	 */
	if ((size = cmd_get_data_size(argv[0], 4)) < 0)
		return 1;

	/* Address is always specified.
	*/
	addr = simple_strtoul(argv[1], NULL, 16);

	/* Length is the number of objects, not number of bytes.
	*/
	length = simple_strtoul(argv[2], NULL, 16);

	bytes = size * length;
	buf = map_sysmem(addr, bytes);

	/* We want to optimize the loops to run as fast as possible.
	 * If we have only one object, just run infinite loops.
	 */
	if (length == 1) {
		if (size == 4) {
			longp = (uint *)buf;
			for (;;)
				i = *longp;
		}
		if (size == 2) {
			shortp = (ushort *)buf;
			for (;;)
				i = *shortp;
		}
		cp = (u_char *)buf;
		for (;;)
			i = *cp;
	}

	if (size == 4) {
		for (;;) {
			longp = (uint *)buf;
			i = length;
			while (i-- > 0)
				*longp++;
		}
	}
	if (size == 2) {
		for (;;) {
			shortp = (ushort *)buf;
			i = length;
			while (i-- > 0)
				*shortp++;
		}
	}
	for (;;) {
		cp = (u_char *)buf;
		i = length;
		while (i-- > 0)
			*cp++;
	}
	unmap_sysmem(buf);
}

#ifdef CONFIG_LOOPW
int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong	addr, length, i, data, bytes;
	int	size;
	volatile uint	*longp;
	volatile ushort *shortp;
	volatile u_char	*cp;
	void *buf;

	if (argc < 4)
		return CMD_RET_USAGE;

	/*
	 * Check for a size specification.
	 * Defaults to long if no or incorrect specification.
	 */
	if ((size = cmd_get_data_size(argv[0], 4)) < 0)
		return 1;

	/* Address is always specified.
	*/
	addr = simple_strtoul(argv[1], NULL, 16);

	/* Length is the number of objects, not number of bytes.
	*/
	length = simple_strtoul(argv[2], NULL, 16);

	/* data to write */
	data = simple_strtoul(argv[3], NULL, 16);

	bytes = size * length;
	buf = map_sysmem(addr, bytes);

	/* We want to optimize the loops to run as fast as possible.
	 * If we have only one object, just run infinite loops.
	 */
	if (length == 1) {
		if (size == 4) {
			longp = (uint *)buf;
			for (;;)
				*longp = data;
					}
		if (size == 2) {
			shortp = (ushort *)buf;
			for (;;)
				*shortp = data;
		}
		cp = (u_char *)buf;
		for (;;)
			*cp = data;
	}

	if (size == 4) {
		for (;;) {
			longp = (uint *)buf;
			i = length;
			while (i-- > 0)
				*longp++ = data;
		}
	}
	if (size == 2) {
		for (;;) {
			shortp = (ushort *)buf;
			i = length;
			while (i-- > 0)
				*shortp++ = data;
		}
	}
	for (;;) {
		cp = (u_char *)buf;
		i = length;
		while (i-- > 0)
			*cp++ = data;
	}
}
#endif /* CONFIG_LOOPW */

static ulong mem_test_alt(vu_long *start, vu_long *end)
{
	vu_long *addr;
	ulong errs = 0;
	ulong val, readback;
	int j;
	vu_long len;
	vu_long offset;
	vu_long test_offset;
	vu_long pattern;
	vu_long temp;
	vu_long anti_pattern;
	vu_long num_words;
#if defined(CONFIG_SYS_MEMTEST_SCRATCH)
	vu_long *dummy = (vu_long *)CONFIG_SYS_MEMTEST_SCRATCH;
#else
	vu_long *dummy = NULL;	/* yes, this is address 0x0, not NULL */
#endif
	static const ulong bitpattern[] = {
		0x00000001,	/* single bit */
		0x00000003,	/* two adjacent bits */
		0x00000007,	/* three adjacent bits */
		0x0000000F,	/* four adjacent bits */
		0x00000005,	/* two non-adjacent bits */
		0x00000015,	/* three non-adjacent bits */
		0x00000055,	/* four non-adjacent bits */
		0xaaaaaaaa,	/* alternating 1/0 */
	};

		/*
		 * Data line test: write a pattern to the first
		 * location, write the 1's complement to a 'parking'
		 * address (changes the state of the data bus so a
		 * floating bus doesn't give a false OK), and then
		 * read the value back. Note that we read it back
		 * into a variable because the next time we read it,
		 * it might be right (been there, tough to explain to
		 * the quality guys why it prints a failure when the
		 * "is" and "should be" are obviously the same in the
		 * error message).
		 *
		 * Rather than exhaustively testing, we test some
		 * patterns by shifting '1' bits through a field of
		 * '0's and '0' bits through a field of '1's (i.e.
		 * pattern and ~pattern).
		 */
		addr = start;
		for (j = 0; j < sizeof(bitpattern) / sizeof(bitpattern[0]);
				j++) {
		    val = bitpattern[j];
		    for (; val != 0; val <<= 1) {
			*addr  = val;
			*dummy  = ~val; /* clear the test data off the bus */
			readback = *addr;
			if(readback != val) {
				printf("FAILURE (data line): "
					"expected %08lx, actual %08lx\n",
						val, readback);
				errs++;
				if (ctrlc()) {
					putc('\n');
					return -1;
				}
			}
			*addr  = ~val;
			*dummy  = val;
			readback = *addr;
			if (readback != ~val) {
				printf("FAILURE (data line): "
					"Is %08lx, should be %08lx\n",
						readback, ~val);
				errs++;
				if (ctrlc()) {
					putc('\n');
					return -1;
				}
			}
		    }
		}

		/*
		 * Based on code whose Original Author and Copyright
		 * information follows: Copyright (c) 1998 by Michael
		 * Barr. This software is placed into the public
		 * domain and may be used for any purpose. However,
		 * this notice must not be changed or removed and no
		 * warranty is either expressed or implied by its
		 * publication or distribution.
		 */

		/*
		 * Address line test
		 *
		 * Description: Test the address bus wiring in a
		 *              memory region by performing a walking
		 *              1's test on the relevant bits of the
		 *              address and checking for aliasing.
		 *              This test will find single-bit
		 *              address failures such as stuck-high,
		 *              stuck-low, and shorted pins. The base
		 *              address and size of the region are
		 *              selected by the caller.
		 *
		 * Notes:	For best results, the selected base
		 *              address should have enough LSB 0's to
		 *              guarantee single address bit changes.
		 *              For example, to test a 64-Kbyte
		 *              region, select a base address on a
		 *              64-Kbyte boundary. Also, select the
		 *              region size as a power-of-two if at
		 *              all possible.
		 *
		 * Returns:     0 if the test succeeds, 1 if the test fails.
		 */
		len = ((ulong)end - (ulong)start)/sizeof(vu_long);
		pattern = (vu_long) 0xaaaaaaaa;
		anti_pattern = (vu_long) 0x55555555;

		debug("%s:%d: length = 0x%.8lx\n",
			__func__, __LINE__, len);
		/*
		 * Write the default pattern at each of the
		 * power-of-two offsets.
		 */
		for (offset = 1; offset < len; offset <<= 1)
			start[offset] = pattern;

		/*
		 * Check for address bits stuck high.
		 */
		test_offset = 0;
		start[test_offset] = anti_pattern;

		for (offset = 1; offset < len; offset <<= 1) {
		    temp = start[offset];
		    if (temp != pattern) {
			printf("\nFAILURE: Address bit stuck high @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx\n",
				(ulong)&start[offset], pattern, temp);
			errs++;
			if (ctrlc()) {
			    putc('\n');
			    return -1;
			}
		    }
		}
		start[test_offset] = pattern;
		WATCHDOG_RESET();

		/*
		 * Check for addr bits stuck low or shorted.
		 */
		for (test_offset = 1; test_offset < len; test_offset <<= 1) {
		    start[test_offset] = anti_pattern;

		    for (offset = 1; offset < len; offset <<= 1) {
			temp = start[offset];
			if ((temp != pattern) && (offset != test_offset)) {
			    printf("\nFAILURE: Address bit stuck low or shorted @"
				" 0x%.8lx: expected 0x%.8lx, actual 0x%.8lx\n",
				(ulong)&start[offset], pattern, temp);
			    errs++;
			    if (ctrlc()) {
				putc('\n');
				return -1;
			    }
			}
		    }
		    start[test_offset] = pattern;
		}

		/*
		 * Description: Test the integrity of a physical
		 *		memory device by performing an
		 *		increment/decrement test over the
		 *		entire region. In the process every
		 *		storage bit in the device is tested
		 *		as a zero and a one. The base address
		 *		and the size of the region are
		 *		selected by the caller.
		 *
		 * Returns:     0 if the test succeeds, 1 if the test fails.
		 */
		num_words = ((ulong)end - (ulong)start)/sizeof(vu_long) + 1;

		/*
		 * Fill memory with a known pattern.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
			WATCHDOG_RESET();
			start[offset] = pattern;
		}

		/*
		 * Check each location and invert it for the second pass.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
		    WATCHDOG_RESET();
		    temp = start[offset];
		    if (temp != pattern) {
			printf("\nFAILURE (read/write) @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx)\n",
				(ulong)&start[offset], pattern, temp);
			errs++;
			if (ctrlc()) {
				putc('\n');
				return -1;
			}
		    }

		    anti_pattern = ~pattern;
		    start[offset] = anti_pattern;
		}

		/*
		 * Check each location for the inverted pattern and zero it.
		 */
		for (pattern = 1, offset = 0; offset < num_words; pattern++, offset++) {
		    WATCHDOG_RESET();
		    anti_pattern = ~pattern;
		    temp = start[offset];
		    if (temp != anti_pattern) {
			printf("\nFAILURE (read/write): @ 0x%.8lx:"
				" expected 0x%.8lx, actual 0x%.8lx)\n",
				(ulong)&start[offset], anti_pattern, temp);
			errs++;
			if (ctrlc()) {
				putc('\n');
				return -1;
			}
		    }
		    start[offset] = 0;
		}

	return 0;
}

static ulong mem_test_quick(vu_long *start, vu_long *end, vu_long pattern,
			    int iteration)
{
	vu_long *addr;
	ulong errs = 0;
	ulong incr;
	ulong val, readback;

	/* Alternate the pattern */
	incr = 1;
	if (iteration & 1) {
		incr = -incr;
		/*
		 * Flip the pattern each time to make lots of zeros and
		 * then, the next time, lots of ones.  We decrement
		 * the "negative" patterns and increment the "positive"
		 * patterns to preserve this feature.
		 */
		if (pattern & 0x80000000)
			pattern = -pattern;	/* complement & increment */
		else
			pattern = ~pattern;
	}
		printf("\rPattern %08lX  Writing..."
			"%12s"
			"\b\b\b\b\b\b\b\b\b\b",
			pattern, "");

		for (addr = start, val = pattern; addr < end; addr++) {
			WATCHDOG_RESET();
			*addr = val;
			val += incr;
		}

		puts("Reading...");

		for (addr = start, val = pattern; addr < end; addr++) {
			WATCHDOG_RESET();
			readback = *addr;
			if (readback != val) {
				printf("\nMem error @ 0x%08X: "
					"found %08lX, expected %08lX\n",
					(uint)(uintptr_t)addr, readback, val);
				errs++;
				if (ctrlc()) {
					putc('\n');
					return -1;
				}
			}
			val += incr;
		}

	return 0;
}

/*
 * Perform a memory test. A more complete alternative test can be
 * configured using CONFIG_SYS_ALT_MEMTEST. The complete test loops until
 * interrupted by ctrl-c or by a failure of one of the sub-tests.
 */
static int do_mem_mtest(cmd_tbl_t *cmdtp, int flag, int argc,
			char * const argv[])
{
	vu_long *start, *end;
	int iteration_limit;
	int ret;
	ulong errs = 0;	/* number of errors, or -1 if interrupted */
	ulong pattern;
	int iteration;
#if defined(CONFIG_SYS_ALT_MEMTEST)
	const int alt_test = 1;
#else
	const int alt_test = 0;
#endif

	if (argc > 1)
		start = (ulong *)simple_strtoul(argv[1], NULL, 16);
	else
		start = (ulong *)CONFIG_SYS_MEMTEST_START;

	if (argc > 2)
		end = (ulong *)simple_strtoul(argv[2], NULL, 16);
	else
		end = (ulong *)(CONFIG_SYS_MEMTEST_END);

	if (argc > 3)
		pattern = (ulong)simple_strtoul(argv[3], NULL, 16);
	else
		pattern = 0;

	if (argc > 4)
		iteration_limit = (ulong)simple_strtoul(argv[4], NULL, 16);
	else
		iteration_limit = 0;

	printf("Testing %08x ... %08x:\n", (uint)(uintptr_t)start,
	       (uint)(uintptr_t)end);
	debug("%s:%d: start 0x%p end 0x%p\n",
		__func__, __LINE__, start, end);

	for (iteration = 0;
			!iteration_limit || iteration < iteration_limit;
			iteration++) {
		if (ctrlc()) {
			putc('\n');
			errs = -1UL;
			break;
		}

		printf("Iteration: %6d\r", iteration + 1);
		debug("\n");
		if (alt_test)
			errs = mem_test_alt(start, end);
		else
			errs = mem_test_quick(start, end, pattern, iteration);
	}

	if (errs == -1UL) {
		/* Memory test was aborted */
		ret = 1;
	} else {
		printf("Tested %d iteration(s) with %lu errors.\n",
			iteration, errs);
		ret = errs != 0;
	}

	return ret;	/* not reached */
}


/* Modify memory.
 *
 * Syntax:
 *	mm{.b, .w, .l} {addr}
 *	nm{.b, .w, .l} {addr}