Remove debug output and add a little documentation

nand-image-builder.c

@@ -54,12 +54,20 @@ int page_size = 2048;
 /**
  *
  * This program reads raw NAND image from standard input and updates ECC bytes in the OOB block for each sector.
- * Data layout is as following:
+ * Data layout is as following (listing only tested geometrys):
  *
  * 2 KB page, consisting of 4 x 512 B sectors
  * 64 bytes OOB, consisting of 4 x 16 B OOB regions, one for each sector
  *
- * In each OOB region, the first 9 1/2 bytes are user defined and the remaining 6 1/2 bytes are ECC.
+ * ./nand-image-builder -i infile -o outfile -b 131072 -p 2048 -s 64 -e 4 -m 14
+ *
+ * or
+ *
+ * 2 KB page, consisting of 4 x 512 B sectors
+ * 128 bytes OOB, consisting of 4 x 32 B OOB regions, one for each sector
+ * in this case only 4 x 27 bytes are used as spare area
+ *
+ * ./nand-image-builder -i infile -o outfile -b 131072 -p 2048 -s 128 -e 8 -m 14
  *
  */
 
@@ -76,6 +84,8 @@ void print_usage(void)
     printf("\t -m field order\n");
     printf("Default command is:\n");
     printf("./nand-image-builder -i infile -o outfile -b 131072 -p 2048 -s 64 -e 4 -m 14\n");
+    printf("Example command is:\n");
+    printf("./nand-image-builder -i infile -o outfile -b 131072 -p 2048 -s 128 -e 8 -m 14\n");
     return;
 }
 
@@ -225,6 +235,7 @@ int main(int argc, char **argv)
     /* Number of ecc_code bytes, v = ceil(p/8) = ceil(m*t/8) = p_partial_page_size+s-u */
     oob_ecc_len = (sector_sz + oob_sz) - data_bytes;
 
+    /* Number of ecc bytes per sector (sub page) depending on the ecc level */
     if        (ecc_level == 4) {
         oob_ecc_sz = 16;
     } else if (ecc_level == 8) {
@@ -294,10 +305,10 @@ int main(int argc, char **argv)
 
         numBytesRead = fread(page_buffer, (size_t)1, (sector_sz)*SECTORS_PER_PAGE, in_file);
         totalBytesRead += numBytesRead;
-	printf("Fread %d\n", totalBytesRead);
+
         if (numBytesRead == 0)
         {
-            printf("Fread failed or file size is zero\r\n");
+            printf("Fread failed or file size is zero or out of data\r\n");
             goto exit;
         }
 
@@ -321,7 +332,6 @@ int main(int argc, char **argv)
         {
             const uint8_t *sector_data = page_buffer + sector_sz * i;
             uint8_t *sector_oob = page_buffer + sector_sz * SECTORS_PER_PAGE + oob_ecc_sz * i;
-           	printf("offset %d\n", sector_sz * SECTORS_PER_PAGE + oob_ecc_sz * i);
 
             if (erase_block)
             {