Messages in this thread | | | Subject | Re: [PATCH 00/22 take 3] UBI: Unsorted Block Images | From | Thomas Gleixner <> | Date | Mon, 26 Mar 2007 12:02:40 +0200 |
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On Mon, 2007-03-26 at 10:45 +0100, David Woodhouse wrote: > On Mon, 2007-03-26 at 03:04 +0200, Jörn Engel wrote: > > That limitation stems from ECC and ECC is done in software. Currently > > everyone and his dog is doing ECC in chunks of 256 bytes on NAND. So > > your minimum write size is 256 bytes _if you care about ECC_. If you > > don't care, you can write single bits on NAND, just as you can on NOR. > > No, on NAND flash it's a limitation of the hardware. The number of write > cycles you can perform to a given page is limited. Exceed it and the > contents of that page become undefined due to leakage, until you next > erase it.
Right and you cannot write to random locations in a page. The write chunks have to be in consecutive order. If you write 0xAA to offset 0, you cannot rewrite it to 0x00 later without risking corruption.
tglx
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