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NOR: add FIXMEs for writing ones

It can invalidate ECC codes, and in general is not guaranteed
to work.  (However on some chips it _appears_ to behave.)  Just
don't do it; don't write in those cases.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
tags/v0.4.0-rc2
David Brownell 12 years ago
parent
commit
296a011db5
2 changed files with 11 additions and 2 deletions
  1. +6
    -0
      TODO
  2. +5
    -2
      src/flash/nor/core.c

+ 6
- 0
TODO View File

@@ -209,6 +209,12 @@ https://lists.berlios.de/pipermail/openocd-development/2009-October/011506.html
- ocl
- str9xpec

- Don't expect writing all-ones to be a safe way to write without
changing bit values. Minimally it loses on flash modules with
internal ECC, where it may change the ECC.
- NOR flash_write_unlock() does that between sectors
- there may be other cases too

@subsection thelistflashcfi CFI

- finish implementing bus width/chip width handling (suggested by NC)


+ 5
- 2
src/flash/nor/core.c View File

@@ -449,9 +449,12 @@ int flash_write_unlock(struct target *target, struct image *image,
break;
}

/* REVISIT This needlessly touches sectors BETWEEN the
/* FIXME This needlessly touches sectors BETWEEN the
* sections it's writing. Without auto erase, it just
* writes ones; unlikely to destroy data.
* writes ones. That WILL INVALIDATE data in cases
* like Stellaris Tempest chips, corrupting internal
* ECC codes; and at least FreeScale suggests issues
* with that approach (in HC11 documentation).
*
* With auto erase enabled, data in those sectors will
* be needlessly destroyed; and some of the limited


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