Hir, sir 
  Thank you for you help about the work on yaffs, and now I want to add ECC check. 
I configure the kernel to enable ECC Check, but when I run the kernel ...
There is :  Reading data from NAND FLASH without ECC is not recommended
  I use your s3c2410nd.c, the message is in nand.c 
int eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE; ////????????????
int   *oob_config = oobsel->eccpos;
I don't know where enable the  oob->useecc ?
Thank you !