[PATCH 0/7] UBIFS: fix recovery on CFI NOR

Artem Bityutskiy dedekind1 at gmail.com
Wed Feb 2 12:16:11 EST 2011


On Wed, 2011-02-02 at 16:21 +0100, Holger Brunck wrote:
> I have tested this patches on an ppc82xx and ppc83xx boards with different NOR
> flashes with different writebuffers (64 and 1024 bytes) and check wether I am
> able to mount previous created UBIFS partitions and this works without any
> problems. So the incompatbility seems to be solved. Additionaly I tried it on a
> NAND based system and this runs also without problems.

OK, thanks!

> Another question related to the writebuffer adaptions for UBI. What should be
> done during creation of ubi images on a host system with ubinize if your patches
> find their way in the "standard" UBI/UBIFS code. 

Nothing, when creating images you specify min. I/O size, which is 1 in
case of NOR.

> In the past we had "only" NOR
> flashes with a writebuffer of 64 bytes and we create our ubi images without the
> -m parameter during executing ubinize for the esw image.

No, you always specify 1. Your flash still allows writing 1 byte at a
time, and this is the minimum, so you set -m 1.

64 is the internal detail, the "optimal" write size. UBIFS will
automatically pick it up and will try to write in 64-byte chunks at a
time, but not always, only when it is possible.

>  Now we got a new flash
> with writebuffer = 1024. Whats the way forward in the future? Is it ok to omit
> the "-m" parameter or do we have to create the images with "-m 64" or "-m 1024"?

Similarly, just use -m 1

Best Regards,
Artem Bityutskiy (Артём Битюцкий)

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