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 --- common/cmd_sf.c | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/common/cmd_sf.c b/common/cmd_sf.c index d97d4a5..0666f52 100644 --- a/common/cmd_sf.c +++ b/common/cmd_sf.c @@ -134,8 +134,10 @@ 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); @@ -145,6 +147,17 @@ 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;