uboot 2010.03 doesn't use ECC to protect environment

I found the reason for this "Bad NAND, wrong CRC" message.

I assumed that ECC correction is not working, but this was not the reason. Correction works, but the return value of nand_read() is not "0" in case, errors have been corrected.

env_relocate_spec() calls readenv(), which returns with 1 (instead of 0). Then use_default() is called, instead of using the corrected environment.

My soution/patch is the following: env_nand.c - readenv()

    while (amount_loaded < CONFIG_ENV_SIZE && offset < end) {
        if (nand_block_isbad(&nand_info[0], offset)) {
            offset += blocksize;
        } else {
            char_ptr = &buf[amount_loaded];
 -           if (nand_read(&nand_info[0], offset, &len, char_ptr))
 +          err = nand_read(&nand_info[0], offset, &len, char_ptr);
 +          if ( err && (err != -EUCLEAN) ) {
 +                   return 1;     // EUCLEAN is not an Error, shows that bits have been corrected bits
  -                  return 1;
            offset += blocksize;
            amount_loaded += len;
        }
    }
    if (amount_loaded != CONFIG_ENV_SIZE)
        return 1;

    return 0;
}

Also

+ #include <linux/err.h>                // to check for EUCLEAN error from nand_read()

Would be nice is someone could confirm this. Here it works.

Can you please note which PSP version you're using?  Thanks.

Now I am using the latest TI uboot (2010.06). It is based onhttp://arago-project.org/git/projects/?p=u-boot-omap3.git;a=commit;h=ae5aaebb687e4810ed1ea6961cbbd0fbd31f2c35and has some patches TI releases in Juli with PSP 4.02.00.07.

diff -rupN u-boot/common/env_nand.c u-boot_patched/common/env_nand.c
--- u-boot/common/env_nand.c    2011-04-08 22:30:40.000000000 +0200
+++ u-boot_patched/common/env_nand.c    2011-10-25 13:48:52.000000000 +0200
@@ -34,6 +34,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <linux/err.h>                //  to check for EUCLEAN error from nand_read()
 #include <environment.h>
 #include <linux/stddef.h>
 #include <malloc.h>
@@ -265,7 +266,7 @@ int readenv (size_t offset, u_char * buf
     size_t end = offset + CONFIG_ENV_RANGE;
     size_t amount_loaded = 0;
     size_t blocksize, len;
-
+    int err;
     u_char *char_ptr;
 
     /* fail if no nand detected */
@@ -282,8 +283,9 @@ int readenv (size_t offset, u_char * buf
             offset += blocksize;
         } else {
             char_ptr = &buf[amount_loaded];
-            if (nand_read(&nand_info[0], offset, &len, char_ptr))
-                return 1;
+            err = nand_read(&nand_info[0], offset, &len, char_ptr);
+            if ( err && (err != -EUCLEAN) )
+                    return 1;     // EUCLEAN is not an Error, shows that bits have been corrected bits
             offset += blocksize;
             amount_loaded += len;
         }

----------------------

What is strange to me: Looking at this it seems that all uboots (not just OMAPs) have a problem with Error correction in uboot environment.

Best regards

Arno