[U-Boot] [PATCH v2 0/2] SPI flash update command
Hi,
this patchset allows "sf update" to erase+write a number of bytes which is not a multiple of the sector size. Start address must still be sector-aligned though.
The first patch trivially makes it such it will always erase an entire sector before writing, regardless of the amount of data to write (i.e. the last sector is erased completely before writing it only partially).
The second patch just makes sure that the original data at the end of the sector is written back so to apparently remain unchanged.
Changes from v1 [April, 03, 2012 (!)]: - Rebased on top of u-boot-spi/master
Gerlando Falauto (2): cmd_sf: let "sf update" erase last sector as a whole cmd_sf: "sf update" preserve the final part of the last sector
common/cmd_sf.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
make "sf update" work with unaligned `len' parameter, by deleting the whole last sector before writing, so to allow for:
sf update ${load_addr_r} 0 ${filesize}
Signed-off-by: Gerlando Falauto gerlando.falauto@keymile.com Cc: Valentin Longchamp valentin.longchamp@keymile.com Cc: Holger Brunck holger.brunck@keymile.com Acked-by: Simon Glass sjg@chromium.org --- common/cmd_sf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/common/cmd_sf.c b/common/cmd_sf.c index 19b0dc9..ab35a94 100644 --- a/common/cmd_sf.c +++ b/common/cmd_sf.c @@ -160,7 +160,8 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, *skipped += len; return NULL; } - if (spi_flash_erase(flash, offset, len)) + /* Erase the entire sector */ + if (spi_flash_erase(flash, offset, flash->sector_size)) return "erase"; if (spi_flash_write(flash, offset, len, buf)) return "write";
Since "sf update" erases the last block as a whole, but only rewrites the meaningful initial part of it, the rest would be left erased, potentially erasing meaningful information. So, as a safety measure, have it rewrite the original content.
Signed-off-by: Gerlando Falauto gerlando.falauto@keymile.com Cc: Valentin Longchamp valentin.longchamp@keymile.com Cc: Holger Brunck holger.brunck@keymile.com Acked-by: Simon Glass sjg@chromium.org --- common/cmd_sf.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/common/cmd_sf.c b/common/cmd_sf.c index ab35a94..fb87d24 100644 --- a/common/cmd_sf.c +++ b/common/cmd_sf.c @@ -152,8 +152,10 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, { debug("offset=%#x, sector_size=%#x, len=%#zx\n", offset, flash->sector_size, len); - if (spi_flash_read(flash, offset, len, cmp_buf)) + /* Read the entire sector so to allow for rewriting */ + if (spi_flash_read(flash, offset, flash->sector_size, cmp_buf)) return "read"; + /* Compare only what is meningful (len) */ if (memcmp(cmp_buf, buf, len) == 0) { debug("Skip region %x size %zx: no change\n", offset, len); @@ -163,6 +165,17 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, /* Erase the entire sector */ if (spi_flash_erase(flash, offset, flash->sector_size)) return "erase"; + /* If it's a partial sector, preserve the existing part */ + if (len != flash->sector_size) { + /* Overwrite the first part of the sector with input data */ + memcpy(cmp_buf, buf, len); + /* Rewrite the whole sector with original data at the end */ + if (spi_flash_write(flash, offset, flash->sector_size, + cmp_buf)) + return "write"; + return NULL; + } + /* Rewrite the whole block from the source */ if (spi_flash_write(flash, offset, len, buf)) return "write"; return NULL;
Hi,
Thanks for the v2.
On Fri, Jun 28, 2013 at 1:13 PM, Gerlando Falauto gerlando.falauto@keymile.com wrote:
Since "sf update" erases the last block as a whole, but only rewrites the meaningful initial part of it, the rest would be left erased, potentially erasing meaningful information. So, as a safety measure, have it rewrite the original content.
Signed-off-by: Gerlando Falauto gerlando.falauto@keymile.com Cc: Valentin Longchamp valentin.longchamp@keymile.com Cc: Holger Brunck holger.brunck@keymile.com Acked-by: Simon Glass sjg@chromium.org
common/cmd_sf.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/common/cmd_sf.c b/common/cmd_sf.c index ab35a94..fb87d24 100644 --- a/common/cmd_sf.c +++ b/common/cmd_sf.c @@ -152,8 +152,10 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, { debug("offset=%#x, sector_size=%#x, len=%#zx\n", offset, flash->sector_size, len);
if (spi_flash_read(flash, offset, len, cmp_buf))
/* Read the entire sector so to allow for rewriting */if (spi_flash_read(flash, offset, flash->sector_size, cmp_buf)) return "read";/* Compare only what is meningful (len) */ if (memcmp(cmp_buf, buf, len) == 0) { debug("Skip region %x size %zx: no change\n", offset, len);@@ -163,6 +165,17 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, /* Erase the entire sector */ if (spi_flash_erase(flash, offset, flash->sector_size)) return "erase";
/* If it's a partial sector, preserve the existing part */if (len != flash->sector_size) {/* Overwrite the first part of the sector with input data */memcpy(cmp_buf, buf, len);
Can comment about memcpy() here, as Simon is also asked in v1 http://patchwork.ozlabs.org/patch/150468/
-- Thanks, Jagan.
/* Rewrite the whole sector with original data at the end */if (spi_flash_write(flash, offset, flash->sector_size,cmp_buf))return "write";return NULL;}/* Rewrite the whole block from the source */ if (spi_flash_write(flash, offset, len, buf)) return "write"; return NULL;-- 1.7.10.1
Hi,
On 07/03/2013 05:04 PM, Jagan Teki wrote:
Hi,
Thanks for the v2.
On Fri, Jun 28, 2013 at 1:13 PM, Gerlando Falauto gerlando.falauto@keymile.com wrote:
Since "sf update" erases the last block as a whole, but only rewrites the meaningful initial part of it, the rest would be left erased, potentially erasing meaningful information. So, as a safety measure, have it rewrite the original content.
Signed-off-by: Gerlando Falauto gerlando.falauto@keymile.com Cc: Valentin Longchamp valentin.longchamp@keymile.com Cc: Holger Brunck holger.brunck@keymile.com Acked-by: Simon Glass sjg@chromium.org
common/cmd_sf.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/common/cmd_sf.c b/common/cmd_sf.c index ab35a94..fb87d24 100644 --- a/common/cmd_sf.c +++ b/common/cmd_sf.c @@ -152,8 +152,10 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, { debug("offset=%#x, sector_size=%#x, len=%#zx\n", offset, flash->sector_size, len);
if (spi_flash_read(flash, offset, len, cmp_buf))
/* Read the entire sector so to allow for rewriting */if (spi_flash_read(flash, offset, flash->sector_size, cmp_buf)) return "read";/* Compare only what is meningful (len) */ if (memcmp(cmp_buf, buf, len) == 0) { debug("Skip region %x size %zx: no change\n", offset, len);@@ -163,6 +165,17 @@ static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset, /* Erase the entire sector */ if (spi_flash_erase(flash, offset, flash->sector_size)) return "erase";
/* If it's a partial sector, preserve the existing part */if (len != flash->sector_size) {/* Overwrite the first part of the sector with input data */memcpy(cmp_buf, buf, len);Can comment about memcpy() here, as Simon is also asked in v1 http://patchwork.ozlabs.org/patch/150468/
Whoops, sorry! I most probably did not see the comment (stopped reading at the Acked-By line) the first time around and *DEFINITELY* did not see it before posting v2.
I now understand your point, Simon. This would imply two spi_flash_write() operations as opposed to just one, yet allowing for cleaner code. I guess I was originally trying to both preserve the original behavior (always write whole sectors) and save on the number of write operations. But that does not make much sense as we're speaking of an SPI NOR flash here, the only penalty from an extra write operation only comes from the extra SPI command. Not really much.
I'll post a v3 soon.
My apologies again.
Thanks, Gerlando
-- Thanks, Jagan.
/* Rewrite the whole sector with original data at the end */if (spi_flash_write(flash, offset, flash->sector_size,cmp_buf))return "write";return NULL;}/* Rewrite the whole block from the source */ if (spi_flash_write(flash, offset, len, buf)) return "write"; return NULL;-- 1.7.10.1
participants (2)
-
Gerlando Falauto -
Jagan Teki