[U-Boot] dfu: dfu and UBI Volumes

[Heiko Schocher]

Hello Lukasz,

Am 27.05.2013 09:02, schrieb Lukasz Majewski:
> Hi Heiko,
> 
>> Hello Tom,
>>
>> Am 24.05.2013 19:12, schrieb Tom Rini:
>>> On Fri, May 24, 2013 at 07:42:01PM +0300, Pantelis Antoniou wrote:
>>>> Hi Heiko,
>>>>
>>>> On May 24, 2013, at 7:39 PM, Heiko Schocher wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> just digging in DFU support in U-Boot for an upcoming board
>>>>> support based on an AM335x. This board support uses for example a
>>>>> rootfs in an UBI Volume on a NAND flash, and this should be
>>>>> updated with dfu ...
>>>>>
>>>>> How To do this? Current state on this board is to erase the rootfs
>>>>> mtd partition with a nand erase and write the new image using
>>>>> dfu_nand.c ... which calls in the end nand_write ... which is ...
>>>>> lets say ... not the prefered way on an UBI volume ...
>>>>>
>>>>> How to solve this? Any ideas?
>>>>
>>>> Well, what would you like ideally to do? Why is nand_write not
>>>> ideal for a UBI volume.
>>>>
>>>> Note that dfu will skip over the bad blocks... 
>>>
>>> Presumably because they want to replace say ubi0:rootfs (and leave
>>> ubi0:user-data and ubi0:u-boot-env and so forth alone) rather than
>>> write in a new ubi container of everything.
>>>
>>> I would suggest that, so long as our existing UBI infrastructure
>>> allows this, you add a new method, dfu_ubi which takes care of
>>> programming things.  This shouldn't be too bad to write as I've
>>> heard the existing infrastucture was easily expanded for SPI (and
>>> patches are pending a little more clean up prior to posting).
>>
>> This sounds easy ... but they have also raw nand partitions, for
>> example spl partitions on one nand flash ... for which dfu_nand.c
>> fits perfectly ... is it possible to use dfu_nand.c and another
>> dfu_xxx.c at the same time?
> 
> I'm not so familiar with nand devices handling, but in my opinion we
> shall create dfu_ubi.c file. 
> 
> I think that, nand part of dfu handling shall be separated from ubi,
> even if UBI itself is layed on nand.

Yes, I tend also to this .. but not as a separte "dfu interface .."
"dfu nand .." should stay, and each partition should know, if it
is a raw nand, or UBI, or jffs2?,... as like in dfu_mmc.c ... but
this should not be hardcoded in every dfu_xxx.c, instead it should
be something like a subinterface ... if it is possible.

> However, Tom and Pantelis shall give their opinion, since they spent a
> lot of time on forcing dfu_nand.c to work.

Yep, that would be great, as I am a dfu beginner ;-)

bye,
Heiko
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