Can U-Boot create mtdparts from device tree partition info?

[Chuck Meade]

Hi Alex,

On Thu, Mar 7, 2024 at 4:17 AM Alexander Dahl <ada at thorsis.com> wrote:

> Hello Chuck,
>
> Am Wed, Mar 06, 2024 at 11:48:39AM -0500 schrieb Chuck Meade:
> > Hello,
> >
> > In looking through the source, I'm not yet seeing logic that allows
> U-Boot
> > to actually use MTD partition information found in the device tree.  Does
> > this logic exist and I'm just missing it?  Or do I need to parse the
> device
> > tree partitions manually and create the mtdparts env variable?
>
> U-Boot can use the partition information from device tree, but not
> with mtdparts.  Try enabling CMD_MTD and run `mtd list` and you will
> see those partitions.
>

Thanks very much for the info.  I am using a U-Boot source tree from a
Petalinux distro, and it turns out that there has been a patch to U-Boot
since this distro was created, involving flash_node in mtdparts.c.  I was
able to incorporate this patch into the U-Boot source tree here and the
"mtd list" version now works as you described.  I can see all of the MTD
partitions from my device tree.

I appreciate your help!  Thanks,
Chuck


>
> > Sorry if this is obvious, I'm just not seeing it yet.  Also, if the
> answer
> > is just to manually enter the mtdparts env variable, and keep it in line
> > with the partition information in the device tree as a manual operation,
> > please let me know that too.  I'm just hoping there is a way to have
> U-Boot
> > get the info from the device tree automatically.
>
> You could do that, but it is probably not necessary.  The 'nand'
> command has some nice ways to enter commands using those mtdparts
> labels, but the 'mtd' covers the basic features like read, write,
> erase too, also with names, but with a different calling syntax for
> the commands.
>
> Unfortunately the 'nand' command uses mtdparts only and does not work
> with partitions defined in DT.  The 'mtd' command is organized
> differently and you might not find all features the 'nand' command
> has.
>
> Greets
> Alex
>
> >
> > Thanks very much,
> > Chuck
>