[Yaffs] Flash Translation Layers and Me

[Chris Williams]

Hello,

A tad off-topic to this list, but I wanted to ask about the relative
benefits between using a flash-centric file system versus a translation
layer.

The YAFFS page just says that a translation layer was considered, but in
the end a file system seemed better, without any embellishment.

I have been asked to create a small (code-size) and otherwise memory
friendly filesystem for a DINOR IV device, which appears to have a lot
of the pitfalls of NAND removed (ECC, sequential writes, limited page
write count, etc.) I am currently guessing that the reason a translation
layer wouldn't be so friendly is that you have to use 512 bytes for
every update to the translation table with NAND, even though you would
probably only be using a very small amount of that. However, for the
device I am writing for, it appears to be that I can do byte-level
access, so this wouldn't be an issue.

Is there other issues I need to consider? At the moment, a translation
layer appears to be the simplest solution, but I haven't found any good
discussions on the subject (except the Wikipedia mentioning the PCMCIA
FTL patent.)

Thank you,
Chris Williams

-- 
Chris Williams <chris at cht.co.jp>