Youta Chen wrote:
> Hi ,
>    I want to set up 128GB Nand Flash filesystem in linux. I'm not 
> familiar with YAFFS2, could I ask you that, can YAFFS2 handle such a 
> huge file system? And what's the maximum file system YAFFS2 can handle 
> on paper? That's to say, we could assume the RAM is large enough.
> 
>   Here is  yaffs_PackedTags2TagsPart definition in 
> /yaffs2/yaffs_packedtags2.h,
> typedef struct {
>         unsigned sequenceNumber;
>          unsigned objectId;
>          unsigned chunkId;
>          unsigned byteCount;
>  } yaffs_PackedTags2TagsPart;
> 
>     That means the maximum filesystem size is:
>      objectID * chunkId * chunkSize = 2^32 * 2 ^32 * 2kB = 2^75KB
>       Am I right? I think there must be filesystem size limit somewhere, 
> but I don't know where.
>       Could you give me any suggestions? Any reply will be appreciate.
>    Thanks!

I think you had better ask this on the YAFFS mailing list, see
http://www.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs. I am not 
familiar with the internals of YAFFS; my goal is to only provide 2 thin 
layers: one between eCos filesystems and YAFFS, one between YAFFS and 
eCos NAND flash.

But as far as common sense suggests: my interpretation would be that 
there is support for 2^32 chunks, and chunks are often 2KB. So, 2^32 * 
2^11 is the number of bytes supported, which would be 8TB if I'm not 
confused; and more for larger chunks. And I *think* that objectID is 
something related to the file system, not to the flash.

Rutger