The NOR infrastructure caches some per-sector state, but
it's not used much ... because the cache is not trustworthy.
This patch addresses one part of that problem, by ensuring
that state cached by NOR drivers gets invalidated once we
resume the target -- since targets may then modify sectors.
Now if we see sector protection or erase status marked as
anything other than "unknown", we should be able to rely
on that as being accurate. (That is ... if we assume the
drivers initialize and update this state correctly.)
Another part of that problem is that the cached state isn't
much used (being unreliable, it would have been unsafe).
Those issues can be addressed in later patches.
---
Haven't merged this yet. The effect should be slightly
visible via "flash protect_check" and "flash info" commands;
basically, once you resume, you'll need to protect_check
again.
I'm tempted to rename the new routine to "nor_resume()"
to help nove a way from the bad "all is NOR" assumption...
I'd like to merge this in a few days, to enable various bits of
cleanup which would use the now-more-valid cached state to avoid
needless and/or inappropriate flash ops, and finish fixing
http://sourceforge.net/apps/trac/openocd/ticket/11
src/flash/nor/core.c | 31 +++++++++++++++++++++++++++++++
src/flash/nor/core.h | 3 +++
src/target/target.c | 9 +++++++++
3 files changed, 43 insertions(+)
--- a/src/flash/nor/core.c
+++ b/src/flash/nor/core.c
@@ -657,3 +657,34 @@ int flash_write(struct target *target, s
{
return flash_write_unlock(target, image, written, erase, false);
}
+
+/**
+ * Invalidates cached flash state which a target can change as it runs.
+ *
+ * @param target The target being resumed
+ *
+ * OpenOCD caches some flash state for brief periods. For example, a sector
+ * that is protected must be unprotected before OpenOCD tries to write it,
+ * Also, a sector that's not erased must be erased before it's written.
+ *
+ * As a rule, OpenOCD and target firmware can both modify the flash, so
+ * when a target starts running, OpenOCD needs invalidate its cached state.
+ */
+void flash_resume(struct target *target)
+{
+ struct flash_bank *bank;
+
+ for (bank = flash_banks; bank; bank = bank->next) {
+ int i;
+
+ if (bank->target != target)
+ continue;
+
+ for (i = 0; i < bank->num_sectors; i++) {
+ struct flash_sector *sector = bank->sectors + i;
+
+ sector->is_erased = -1;
+ sector->is_protected = -1;
+ }
+ }
+}
--- a/src/flash/nor/core.h
+++ b/src/flash/nor/core.h
@@ -122,6 +122,9 @@ int flash_erase_address_range(struct tar
*/
int flash_write(struct target *target,
struct image *image, uint32_t *written, int erase);
+
+void flash_resume(struct target *target);
+
/**
* Forces targets to re-examine their erase/protection state.
* This routine must be called when the system may modify the status.
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -35,6 +35,7 @@
#include <helper/time_support.h>
#include <jtag/jtag.h>
+#include <flash/nor/core.h>
#include "target.h"
#include "target_type.h"
@@ -472,6 +473,14 @@ int target_resume(struct target *target,
if ((retval = target->type->resume(target, current, address,
handle_breakpoints, debug_execution)) != ERROR_OK)
return retval;
+ /* Invalidate any cached protect/erase/... flash status, since
+ * almost all targets will now be able modify the flash by
+ * themselves. We want flash drivers and infrastructure to
+ * be able to rely on (non-invalidated) cached state.
+ *
+ * REVISIT do the same for NAND ; maybe other flash flavors too...
+ */
+ flash_resume(target);
return retval;
}
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