[meta-xilinx] u-boot/UBIFS

[Joe Hershberger]

Hi Ed,

On Wed, Sep 23, 2015 at 10:46 AM, Edward Wingate <edwingate8 at gmail.com> wrote:
> On Wed, Sep 23, 2015 at 8:31 AM, Edward Wingate <edwingate8 at gmail.com> wrote:
>> On Wed, Sep 23, 2015 at 7:56 AM, Joe Hershberger
>> <joe.hershberger at gmail.com> wrote:
>>> I'm surprised that you are using "nor0". I wouldn't be surprised if
>>> you are getting a null pointer or garbage dereference since you don't
>>> have a driver that is using the nor subsystem, right?
>>
>> I thought that was the point of that experimental MTD translation
>> layer driver.
>> By enabling it and specifying "nor0=spiXXX.Y", it "does the right thing".
>>
>>> Chances are you need to add a spi flash type to mtdparts, reference
>>> that, then hook it to the serial flash subsystem.
>
> After a little more digging, I think you're right, Joe.
> From the u-boot README:
>
> +               CONFIG_SPI_FLASH_MTD            spi-flash MTD layer
> +
> +               Define this option to use mtd support for spi flash layer, this
> +               adapter is for translating mtd_read/mtd_write commands into
> +               spi_flash_read/spi_flash_write commands. It is not intended to
> +               use it within sf_cmd or the SPI flash subsystem. Such an adapter
> +               is needed for subsystems like UBI which can only operate on top
> +               of the MTD layer.
>
> The experimental driver only translates low-level mtd_read/mtd_write
> commands.  Doesn't look like it covers UBI yet.

That's not how I read that comment. I read it as "You need this to use
UBI, but you don't need it for low-level access. I think you already
have what you need.

I'm gonna guess that if you have this enabled, the only thing you need
to do is debug where the crash is... it may be a simple bug. It looks
like it should work.

Cheers,
-Joe