From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerlando Falauto Date: Fri, 28 Jun 2013 09:43:53 +0200 Subject: [U-Boot] [PATCH v2 2/2] cmd_sf: "sf update" preserve the final part of the last sector In-Reply-To: <1372405433-30384-1-git-send-email-gerlando.falauto@keymile.com> References: <1372405433-30384-1-git-send-email-gerlando.falauto@keymile.com> Message-ID: <1372405433-30384-3-git-send-email-gerlando.falauto@keymile.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 Cc: Valentin Longchamp Cc: Holger Brunck Acked-by: Simon Glass --- 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; -- 1.7.10.1