From 3f18900b19f49a84ba9df56f2e089c255e610011 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Fri, 18 Dec 2009 10:16:52 -0800 Subject: [PATCH] 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 --- NEWS | 2 ++ src/flash/nor/core.c | 44 ++++++++++++++++++++++++++++++++++++-------- 2 files changed, 38 insertions(+), 8 deletions(-) diff --git a/NEWS b/NEWS index 498797b1f..2d01f0049 100644 --- a/NEWS +++ b/NEWS @@ -39,6 +39,8 @@ Flash Layer: - : reference the bank with its defined 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 diff --git a/src/flash/nor/core.c b/src/flash/nor/core.c index c2ea134a3..1873deede 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); }