Thanks for suggestion. I will try it. I am using the Samsung 16MB NAND flash . and separate 3 partitions. /dev/mtd0 is used for kernel img; /dev/mtd1 for general file drive (YAFFS); /dev/mtd2 for initrd.img. The yaffs driver is compiled by module. and set "mount -t yaffs /dev/block1 /mnt/flash" in rcS (setup script). No format the partition in the first mounting. The drive is not always to use, it is just saved the config. file. So, I dont clearly know why the yaffs is corrupt. I check the disk space by "du" command. It said 100% used . And cannot remove any file in this /mnt/flash. therefore , i think it is corrupted. Any ideal?? Thank a lot. Paul ----- Original Message ----- From: "Charles Manning" To: "Paul" ; ; "yaffs list" Sent: Friday, April 18, 2003 4:49 AM Subject: Re: Restore the bad block flag in OOB of NAND flash > On Friday 18 April 2003 05:21, Paul wrote: > > Dear All, > > > > How can I restore the 0xFF in the OOB[5]? i understood the oob[5] is > > the bad block indicator. The YAFFS set accidentally the byte to 0x00 . I > > want to use JFFS2 but the eraseall command said they are invalid block. I > > am > > sure that the block is health . So, I want to force set the oob[5] to > > oxFF, pls. how can i do? Thank you. > > > > Paul > > Generally this is a bad idea to erase bad blocks since destroying factory > marked bad blocks can cause problems through the entire chip (not just the > bad block). eg. Some blocks are marked because a write to the block could > disturb data in another block. > > More recent chips seem to have some hardware "fuse" blown to prevent bad > blocks from being erased. > > One way to achieve what you want is to hack mkyaffs. mkyaffs erases the > blocks in the partition, but first checks for bad block markers. If you > comment out the check then it will erase the block regardless. This will set > all the bits in the block to 1 (including the bad block marker). > > BTW: I am curious as to how YAFFS managed to mark your block bad. > > -- Charles > > > > -------------------------------------------------------------------------- ------------- > This mailing list is hosted by Toby Churchill open software (www.toby-churchill.org). > If mailing list membership is no longer wanted you can remove yourself from the list by > sending an email to yaffs-request@toby-churchill.org with the text "unsubscribe" > (without the quotes) as the subject. > > --------------------------------------------------------------------------------------- This mailing list is hosted by Toby Churchill open software (www.toby-churchill.org). If mailing list membership is no longer wanted you can remove yourself from the list by sending an email to yaffs-request@toby-churchill.org with the text "unsubscribe" (without the quotes) as the subject.