diff --git a/common/cmd_sf.c b/common/cmd_sf.c
index 6e7be81..b1fed6e 100644
--- a/common/cmd_sf.c
+++ b/common/cmd_sf.c
@@ -19,6 +19,59 @@
 
 static struct spi_flash *flash;
 
+
+/*
+ * This function computes the length argument for the erase command.
+ * The length on which the command is to operate can be given in two forms:
+ * 1. <cmd> offset len  - operate on <'offset',  'len')
+ * 2. <cmd> offset +len - operate on <'offset',  'round_up(len)')
+ * If the second form is used and the length doesn't fall on the
+ * sector boundary, than it will be adjusted to the next sector boundary.
+ * If it isn't in the flash, the function will fail (return -1).
+ * Input:
+ *    arg: length specification (i.e. both command arguments)
+ * Output:
+ *    len: computed length for operation
+ * Return:
+ *    1: success
+ *   -1: failure (bad format, bad address).
+*/
+static int sf_parse_len_arg(char *arg, ulong *len)
+{
+	char *ep;
+	char round_up_len; /* indicates if the "+length" form used */
+	ulong sector_size;
+	ulong len_arg;
+
+
+	round_up_len = 0;
+	if (arg && *arg == '+'){
+		round_up_len = 1;
+		++arg;
+	}
+
+	len_arg = simple_strtoul(arg, &ep, 16);
+	if (ep == arg || *ep != '\0')
+		return -1;
+
+	if (round_up_len) {
+		/* Get sector size from flash and round up */
+		sector_size = 	flash->block_size;
+		if (sector_size > 0) {
+			*len = ((((len_arg -1)/sector_size) + 1) * sector_size);
+			if (*len > flash->size) {
+				return -1;
+			}
+		} else {
+			return -1;
+		}
+	} else {
+		*len = len_arg;
+	}
+
+	return 1;
+}
+
 static int do_spi_flash_probe(int argc, char * const argv[])
 {
 	unsigned int bus = 0;
@@ -135,9 +188,11 @@ static int do_spi_flash_erase(int argc, char * const argv[])
 	offset = simple_strtoul(argv[1], &endp, 16);
 	if (*argv[1] == 0 || *endp != 0)
 		goto usage;
-	len = simple_strtoul(argv[2], &endp, 16);
-	if (*argv[2] == 0 || *endp != 0)
+
+	ret = sf_parse_len_arg(argv[2], &len);
+	if (ret != 1) {
 		goto usage;
+	}
 
 	ret = spi_flash_erase(flash, offset, len);
 	if (ret) {
@@ -149,6 +204,7 @@ static int do_spi_flash_erase(int argc, char * const argv[])
 
 usage:
 	puts("Usage: sf erase offset len\n");
+	puts("       sf erase offset +len\n");
 	return 1;
 }
 
@@ -189,5 +245,6 @@ U_BOOT_CMD(
 	"				  `offset' to memory at `addr'\n"
 	"sf write addr offset len	- write `len' bytes from memory\n"
 	"				  at `addr' to flash at `offset'\n"
-	"sf erase offset len		- erase `len' bytes from `offset'"
+	"sf erase offset [+]len		- erase `len' bytes from `offset'\n"
+	"				- `+len' round up `len' to block size"
 );
diff --git a/drivers/mtd/spi/atmel.c b/drivers/mtd/spi/atmel.c
index 8d02169..ec1a7b7 100644
--- a/drivers/mtd/spi/atmel.c
+++ b/drivers/mtd/spi/atmel.c
@@ -539,6 +539,7 @@ struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode)
 	asf->flash.size = page_size * params->pages_per_block
 				* params->blocks_per_sector
 				* params->nr_sectors;
+	asf->flash.block_size = page_size;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, page_size);
diff --git a/drivers/mtd/spi/macronix.c b/drivers/mtd/spi/macronix.c
index 76d5284..98e553b 100644
--- a/drivers/mtd/spi/macronix.c
+++ b/drivers/mtd/spi/macronix.c
@@ -247,8 +247,7 @@ int macronix_erase(struct spi_flash *flash, u32 offset, size_t len)
 	 * when possible.
 	 */
 
-	sector_size = mcx->params->page_size * mcx->params->pages_per_sector
-			* mcx->params->sectors_per_block;
+	sector_size = mcx->flash.block_size;
 
 	if (offset % sector_size || len % sector_size) {
 		debug("SF: Erase offset/length not multiple of sector size\n");
@@ -329,6 +328,7 @@ struct spi_flash *spi_flash_probe_macronix(struct spi_slave *spi, u8 *idcode)
 	mcx->flash.read = macronix_read_fast;
 	mcx->flash.size = params->page_size * params->pages_per_sector
 	    * params->sectors_per_block * params->nr_blocks;
+	mcx->flash.block_size = mcx->flash.size/params->nr_blocks;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, params->page_size);
diff --git a/drivers/mtd/spi/spansion.c b/drivers/mtd/spi/spansion.c
index d6c1a5f..e5ba4f4 100644
--- a/drivers/mtd/spi/spansion.c
+++ b/drivers/mtd/spi/spansion.c
@@ -255,7 +255,7 @@ int spansion_erase(struct spi_flash *flash, u32 offset, size_t len)
 	 * when possible.
 	 */
 
-	sector_size = spsn->params->page_size * spsn->params->pages_per_sector;
+	sector_size = spsn->flash.block_size;
 
 	if (offset % sector_size || len % sector_size) {
 		debug("SF: Erase offset/length not multiple of sector size\n");
@@ -342,6 +342,7 @@ struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode)
 	spsn->flash.read = spansion_read_fast;
 	spsn->flash.size = params->page_size * params->pages_per_sector
 	    * params->nr_sectors;
+	spsn->flash.block_size = spsn->flash.size/params->nr_sectors;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, params->page_size);
diff --git a/drivers/mtd/spi/sst.c b/drivers/mtd/spi/sst.c
index 2557891..4ac6783 100644
--- a/drivers/mtd/spi/sst.c
+++ b/drivers/mtd/spi/sst.c
@@ -261,7 +261,7 @@ sst_erase(struct spi_flash *flash, u32 offset, size_t len)
 	 * when possible.
 	 */
 
-	sector_size = SST_SECTOR_SIZE;
+	sector_size = flash->block_size;
 
 	if (offset % sector_size) {
 		debug("SF: Erase offset not multiple of sector size\n");
@@ -363,6 +363,7 @@ spi_flash_probe_sst(struct spi_slave *spi, u8 *idcode)
 	stm->flash.erase = sst_erase;
 	stm->flash.read = sst_read_fast;
 	stm->flash.size = SST_SECTOR_SIZE * params->nr_sectors;
+	stm->flash.block_size = SST_SECTOR_SIZE;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, SST_SECTOR_SIZE);
diff --git a/drivers/mtd/spi/stmicro.c b/drivers/mtd/spi/stmicro.c
index 3134027..8b44fb9 100644
--- a/drivers/mtd/spi/stmicro.c
+++ b/drivers/mtd/spi/stmicro.c
@@ -269,7 +269,7 @@ int stmicro_erase(struct spi_flash *flash, u32 offset, size_t len)
 	 * when possible.
 	 */
 
-	sector_size = stm->params->page_size * stm->params->pages_per_sector;
+	sector_size = stm->flash.block_size;
 
 	if (offset % sector_size || len % sector_size) {
 		debug("SF: Erase offset/length not multiple of sector size\n");
@@ -364,6 +364,7 @@ struct spi_flash *spi_flash_probe_stmicro(struct spi_slave *spi, u8 * idcode)
 	stm->flash.read = stmicro_read_fast;
 	stm->flash.size = params->page_size * params->pages_per_sector
 	    * params->nr_sectors;
+	stm->flash.block_size = stm->flash.size/params->nr_sectors;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, params->page_size);
diff --git a/drivers/mtd/spi/winbond.c b/drivers/mtd/spi/winbond.c
index ff1df25..f760bc2 100644
--- a/drivers/mtd/spi/winbond.c
+++ b/drivers/mtd/spi/winbond.c
@@ -225,7 +225,6 @@ int winbond_erase(struct spi_flash *flash, u32 offset, size_t len)
 {
 	struct winbond_spi_flash *stm = to_winbond_spi_flash(flash);
 	unsigned long sector_size;
-	unsigned int page_shift;
 	size_t actual;
 	int ret;
 	u8 cmd[4];
@@ -236,8 +235,7 @@ int winbond_erase(struct spi_flash *flash, u32 offset, size_t len)
 	 * when possible.
 	 */
 
-	page_shift = stm->params->l2_page_size;
-	sector_size = (1 << page_shift) * stm->params->pages_per_sector;
+	sector_size = stm->flash.block_size;
 
 	if (offset % sector_size || len % sector_size) {
 		debug("SF: Erase offset/length not multiple of sector size\n");
@@ -324,6 +322,8 @@ struct spi_flash *spi_flash_probe_winbond(struct spi_slave *spi, u8 *idcode)
 	stm->flash.size = page_size * params->pages_per_sector
 				* params->sectors_per_block
 				* params->nr_blocks;
+	stm->flash.block_size = (1 << stm->params->l2_page_size) *
+		stm->params->pages_per_sector;
 
 	printf("SF: Detected %s with page size %u, total ",
 	       params->name, page_size);
diff --git a/include/spi_flash.h b/include/spi_flash.h
index 1f8ba29..462bef6 100644
--- a/include/spi_flash.h
+++ b/include/spi_flash.h
@@ -38,6 +38,8 @@ struct spi_flash {
 
 	u32		size;
 
+	u32		block_size;
+
 	int		(*read)(struct spi_flash *flash, u32 offset,
 				size_t len, void *buf);
 	int		(*write)(struct spi_flash *flash, u32 offset,
@@ -67,5 +69,4 @@ static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
 {
 	return flash->erase(flash, offset, len);
 }
-
 #endif /* _SPI_FLASH_H_ */
