cmd_sf: let "sf update" preserve the final part of the last sector

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>
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
This commit is contained in:
Gerlando Falauto 2013-08-27 19:13:57 +05:30 committed by Jagannadha Sutradharudu Teki
parent a928a36ff9
commit b95f958d7d

View File

@ -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 meaningful (len) */
if (memcmp(cmp_buf, buf, len) == 0) {
debug("Skip region %x size %zx: no change\n",
offset, len);
@ -163,8 +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";
/* Write the initial part of the block from the source */
if (spi_flash_write(flash, offset, len, buf))
return "write";
/* If it's a partial sector, rewrite the existing part */
if (len != flash->sector_size) {
/* Rewrite the original data to the end of the sector */
if (spi_flash_write(flash, offset + len,
flash->sector_size - len, &cmp_buf[len]))
return "write";
}
return NULL;
}