flash: Add optional verify-after-write feature
Sometimes it might make sense to verify the written data to NOR flash.
This patch adds this feature. To enable this verify-after-write, you
need to define CONFIG_FLASH_VERIFY in your board config header.
Please note that this option is useless in nearly all cases,
since such flash programming errors usually are detected earlier
while unprotecting/erasing/programming. Please only enable
this option if you really know what you are doing.
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/README b/README
index 0bc0af5..862bb3e 100644
--- a/README
+++ b/README
@@ -3248,6 +3248,15 @@
digits and dots. Recommended value: 45 (9..1) for 80
column displays, 15 (3..1) for 40 column displays.
+- CONFIG_FLASH_VERIFY
+ If defined, the content of the flash (destination) is compared
+ against the source after the write operation. An error message
+ will be printed when the contents are not identical.
+ Please note that this option is useless in nearly all cases,
+ since such flash programming errors usually are detected earlier
+ while unprotecting/erasing/programming. Please only enable
+ this option if you really know what you are doing.
+
- CONFIG_SYS_RX_ETH_BUFFER:
Defines the number of Ethernet receive buffers. On some
Ethernet controllers it is recommended to set this value
diff --git a/common/flash.c b/common/flash.c
index 8244ba2..0c57a3f 100644
--- a/common/flash.c
+++ b/common/flash.c
@@ -149,6 +149,9 @@
flash_info_t *info_first = addr2info (addr);
flash_info_t *info_last = addr2info (end );
flash_info_t *info;
+ __maybe_unused char *src_orig = src;
+ __maybe_unused char *addr_orig = (char *)addr;
+ __maybe_unused ulong cnt_orig = cnt;
if (cnt == 0) {
return (ERR_OK);
@@ -185,6 +188,14 @@
addr += len;
src += len;
}
+
+#if defined(CONFIG_FLASH_VERIFY)
+ if (memcmp(src_orig, addr_orig, cnt_orig)) {
+ printf("\nVerify failed!\n");
+ return ERR_PROG_ERROR;
+ }
+#endif /* CONFIG_SYS_FLASH_VERIFY_AFTER_WRITE */
+
return (ERR_OK);
#endif /* CONFIG_SPD823TS */
}