flash/nor/core: Fix chunk size calculation in default_flash_mem_blank_check

Slow version of blank check procedure reads target memory sector-by-sector
using 1 KB chunks. Due to bug in chunk size calculation algorithm the actual
size of the chunk is always 1 KB even if sector size is smaller.
This causes out-of-boundary read of the last sector.

Steps to reproduce:
1) Use target with small sectors (e.g. psoc6 with 512-byte sectors)
2) set WORKAREASIZE_CM0 0
3) flash erase_check 1

Running slow fallback erase check - add working memory
Info : SWD DPIDR 0x6ba02477
Error: Failed to read memory at 0x14008000
unknown error when checking erase state of flash bank #1 at 0x14000000
	Bank is erased

Change-Id: I03d0d5fb3a1950ae6aac425f5e24c7fd94b38325
Signed-off-by: Bohdan Tymkiv <bhdt@cypress.com>
Reviewed-on: http://openocd.zylin.com/4785
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/flash/nor/core.c b/src/flash/nor/core.c
index 0aaa7d26f0b5e58c9f09a7f12f592dfb745ce24a..c541afcd06cccce6243f0e72438d793fb6385ad6 100644 (file)
--- a/src/flash/nor/core.c
+++ b/src/flash/nor/core.c
@@ -322,8 +322,8 @@ static int default_flash_mem_blank_check(struct flash_bank *bank)
                for (j = 0; j < bank->sectors[i].size; j += buffer_size) {
                        uint32_t chunk;
                        chunk = buffer_size;
-                       if (chunk > (j - bank->sectors[i].size))
-                               chunk = (j - bank->sectors[i].size);
+                       if (chunk > (bank->sectors[i].size - j))
+                               chunk = (bank->sectors[i].size - j);
 
                        retval = target_read_memory(target,
                                        bank->base + bank->sectors[i].offset + j,