OOB Location

Hi All,

I have one question regarding JFFS2 on NAND flash. My hardware has a NAND flash controller, which does automatic error correction. It needs 10 bytes for this, which it stores in the OOB area of each page. JFFS2 also stores some information in this area, from locations 8-15 for a 512 page-size NAND flash. Now the issue is that the storage locations as used by our hardware and JFFS2 clash. My first hunch is that its a quirky hardware. My questions is:
Is it possible to use some other location for storing file-system information. Is there an option, so that JFFS2 can store this information in some other area? If yes, how to use this. I saw the 'mkfs.jffs2' help, it does not expose any such option.

Thanks.
Ajay

That's supported. JFFS2 puts the cleanmarker into the bytes which are not used by ECC.

static struct nand_ecclayout rtc_from4_nand_oobinfo = {
	.eccbytes = 32,
	.eccpos = {
		   0, 1, 2, 3, 4, 5, 6, 7,
		   8, 9, 10, 11, 12, 13, 14, 15,
		   16, 17, 18, 19, 20, 21, 22, 23,
		   24, 25, 26, 27, 28, 29, 30, 31},
	.oobfree = {{32, 32}}
};

JFFS2 puts the cleanmarker at offset 32 in OOB.

mkfs.jffs2 does not know anything about the OOB usage scheme at all.

tglx