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Last Post 25 Mar 2015 04:58 PM by  bradb
nand: 100% Warning some of the blocks were not erased
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Author Messages
Oleg Kuryan
New Member
New Member

24 Mar 2015 04:12 PM

    Dear support team,


    I faced with error in NAND erase.

    losh> erase B0 B4096 /dev/nand0;
    erasing nand:  100%
    Warning some of the blocks were not erased
    erased '/dev/nand0' start=0x0: len=0xfff bytes/blocks skipped 1


    I think, as a result I can't successfully write image file to NAND and face with error Scanning JFFS2 FS:

    ### JFFS2 loading 'linux.uboot' to 0x87000000
    Scanning JFFS2 FS:   read_nand_cached: error reading nand off 0x104000 size 8192 bytes
    . done.


    Could you help me solve it?



    Basic Member
    Basic Member

    25 Mar 2015 04:58 PM


    I believe that is correct that the block not erased is a bad block.  In Logic Loader version 2.4.14 you can view the number of bad block using the 'info mem' command.

    Here is an example output from a SOM with no bad blocks.

    losh> info mem

    Configuration of /dev/nand0:
            Total Blocks:           4096
            Bytes Per Block:        16896
            Has Chunks:             yes
            Bad Block:              0
            Total Chunks:           131072
            Chunks Per Block:       32
            Bytes Per Chunk:        528
            Bytes Per Spare:        16

    It is not unusual for NAND memory to have bad blocks. Some NAND memory even come with manufacturer-marked bad blocks. 

    The specification for the NAND used on the i.MX31 allows up to 80 bad blocks.  Here is a link to an application note from ST Micro on bad block management. 

    Here is another forum post on NAND recovery of bad blocks.  



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