[Yaffs] Re: YAFFS fs images not working the way I expect

Thomas Gleixner tglx@linutronix.de
Sat, 23 Oct 2004 00:03:14 +0200


On Fri, 2004-10-22 at 11:33 -0700, David Wuertele wrote:
> Robert> Also, keep in mind that NAND Flashes are not error free and
> Robert> that they are at random places. Using dd (or other, OOB
> Robert> supported util) to preload an image on other NAND flash than
> Robert> it was dumped from is risky. Image might contain valid, live
> Robert> blocks where NAND has faults.
> 
> Yes, I'm aware of that --- I am using dd for testing on my embedded
> system, but when I do the actual manufacturing I will be using a
> programmer which knows how to deal with bad blocks.
> 
> And after I tried the dd test, I checked the partition for bad blocks
> and it has none.  So I know that bad blocks aren't the reason the dd
> test didn't work.

A lot of ppl pointed already out, why dd does not work.

Read also http://www.linux-mtd.infradead.org/tech/nand.html

It will never work the way you expect whether there are bad blocks or
not. You _CANNOT_ use dd for testing on NAND. MTD/utils/nand.... _ARE_
NAND aware, dd is _NOT_ !

Plug the unplugged plug (http://www.bfnet.com) before arguing more about
what you expect.

tglx