On Fri, 1 Jul 2011 11:38:40 -0700 Ran Shalit <ransha...@gmail.com> wrote:
> Hello, > > I am trying to read\write NAND from unaligned offset & length. > I saw Scott Wood patch in > http://lists.denx.de/pipermail/u-boot/2010-August/076435.html for allowing > unaligned length, but I see that it still demands unaligned offset in write, > and also the patch added demand for unaligned offset in reading too. > My question: Should I wrap the call to > nand_read_skip_bad\nand_write_skip_bad to that I will call the function with > aligned offset and then retrieve the data parts which I am intereseted in > (for the write I should also wrap the data of start of page with > "FFFFF..."), > or Is there a way to patch nand_read_skip_bad\nand_write_skip_bad in a way > that I will be able to read\write from unaligned offset ? Because of how we skip bad blocks, you have to start looking for bad blocks at the beginning of the partition (with partition defined loosely as an independent region of flash, which you'll never be accessing as part of a block-skipping access that starts elsewhere), or you could be accessing the wrong offset. Currently we don't have support for performing an access at an address within a partition that has been adjusted due to bad blocks earlier in the partition. So yes, you'll need a wrapper for read. For writes, you'll need to do a read-modify-write sequence on the entire block, after you determine what the proper block is given prior block-skipping. Or better, don't try to use this simplistic mechanism to do writes in the middle of a partition -- use something like ubi that was meant for this. -Scott _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
