Browse Source

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>
tags/v0.4.0-rc1
David Brownell 12 years ago
parent
commit
3f18900b19
2 changed files with 38 additions and 8 deletions
  1. +2
    -0
      NEWS
  2. +36
    -8
      src/flash/nor/core.c

+ 2
- 0
NEWS View File

@@ -39,6 +39,8 @@ Flash Layer:
- <bank_name>: reference the bank with its defined name
- <driver_name>[.N]: reference the driver's Nth bank
New 'nand verify' command to check bank against an image file.
The "flash erase_address" command now rejects partial sectors;
previously it would silently erase extra data.

Board, Target, and Interface Configuration Scripts:
ARM9


+ 36
- 8
src/flash/nor/core.c View File

@@ -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);
}



Loading…
Cancel
Save