From 3f18900b19f49a84ba9df56f2e089c255e610011 Mon Sep 17 00:00:00 2001
From: David Brownell <dbrownell@users.sourceforge.net>
Date: Fri, 18 Dec 2009 10:16:52 -0800
Subject: NOR FLASH: only erase/unlock whole sectors
Much to my surprise, I observed a "flash erase_address ..."
command erasing data which I said should not be erased.
The issue turns out to be generic NOR flash code which was
silently, and rather dangerously, morphing partial-sector
references into unrequested whole-sector ones.
This patch removes that low-level morphing. If desired, it
can and should be done in higher level code. (We might need
to fix some stuff in the GDB server code.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
src/flash/nor/core.c | 44 ++++++++++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 8 deletions(-)
(limited to 'src')
diff --git a/src/flash/nor/core.c b/src/flash/nor/core.c
index c2ea134a..1873deed 100644
--- a/src/flash/nor/core.c
+++ b/src/flash/nor/core.c
@@ -279,11 +279,13 @@ int default_flash_blank_check(struct flash_bank *bank)
return ERROR_OK;
}
+
/* erase given flash region, selects proper bank according to target and address */
static int flash_iterate_address_range(struct target *target, uint32_t addr, uint32_t length,
int (*callback)(struct flash_bank *bank, int first, int last))
{
struct flash_bank *c;
+ uint32_t last_addr = addr + length; /* first address AFTER end */
int first = -1;
int last = -1;
int i;
@@ -306,26 +308,52 @@ static int flash_iterate_address_range(struct target *target, uint32_t addr, uin
return callback(c, 0, c->num_sectors - 1);
}
- /* check whether it fits */
+ /* check whether it all fits in this bank */
if (addr + length - 1 > c->base + c->size - 1)
return ERROR_FLASH_DST_BREAKS_ALIGNMENT;
+ /** @todo: handle erasures that cross into adjacent banks */
+
addr -= c->base;
for (i = 0; i < c->num_sectors; i++)
{
- /* check whether sector overlaps with the given range and is not yet erased */
- if (addr < c->sectors[i].offset + c->sectors[i].size && addr + length > c->sectors[i].offset && c->sectors[i].is_erased != 1) {
- /* if first is not set yet then this is the first sector */
- if (first == -1)
+ struct flash_sector *f = c->sectors + i;
+
+ /* start only on a sector boundary */
+ if (first < 0) {
+ /* is this the first sector? */
+ if (addr == f->offset)
first = i;
- last = i; /* and it is the last one so far in any case */
+ else if (addr < f->offset)
+ break;
}
+
+ /* is this (also?) the last sector? */
+ if (last_addr == f->offset + f->size) {
+ last = i;
+ break;
+ }
+
+ /* MUST finish on a sector boundary */
+ if (last_addr <= f->offset)
+ break;
}
- if (first == -1 || last == -1)
- return ERROR_OK;
+ /* invalid start or end address? */
+ if (first == -1 || last == -1) {
+ LOG_ERROR("address range 0x%8.8x .. 0x%8.8x "
+ "is not sector-aligned",
+ (unsigned) c->base + addr,
+ (unsigned) last_addr - 1);
+ return ERROR_FLASH_DST_BREAKS_ALIGNMENT;
+ }
+ /* The NOR driver may trim this range down, based on
+ * whether or not a given sector is already erased.
+ *
+ * REVISIT should *we* trim it... ?
+ */
return callback(c, first, last);
}
--
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