UBIFS on Atmel Dataflash

[Andre Puschmann]

Hi Artem,

thanks for your prompt reply.

Artem Bityutskiy wrote:
> Yeah, I had a feeling we should not have assumed power of 2. But it was
> so appealing, because we can avoid (slow) divisions when aligning data
> to min. I/O unit boundary. I knew about DataFlash, but it is usually so
> small that I did not expect anyone using UBIFS there.
>
> Are you sure you want ubifs on such a tiny flash? We were really
> targeting to larger ones, say, starting from 64MiB at least.
>   
Mmh, the idea to run UBIFS came up due to a problem with JFFS2 on this
device. So I wanted to use another writeable flash fs to  find out
whether its a fs-problem or a mtd/dataflash one.

So you suggest to stick with JFFS2 in this case?

> Basically, there is not fundamental reasons not to support non-power of
> 2 min. I/O unit size, besides of optimizations. And to fix this, one
> would need to carefully look at / grep for min_io_size usage in both
> UBI/UBIFS, and change stuff like ALIGN(x, c->min_io_size) to something
> else. But there are very many of such places.
>   
Thanks for your explanation.


Best regards,

Andre