[U-Boot] dtoverlay for mx6 ARM

[U-Boot] dtoverlay for mx6 ARM

[Johann Obermayr]

Hello,

for raspberyy pi there are some "features" available.
dtoverlay, dtparam, ...
we have a Freescale mx6 CPU.
How we can add/enable this features ?

regards
   Johann

[U-Boot] dtoverlay for mx6 ARM

[Jakub Kiciński]

On Thu, 11 Jun 2015 21:49:57 +0200, Johann Obermayr wrote:
> Hello,

Hi there,
 
> for raspberyy pi there are some "features" available.
> dtoverlay, dtparam, ...
> we have a Freescale mx6 CPU.
> How we can add/enable this features ?

I'm new to U-Boot but on RPi the "features" are provided by their
proprietary firmware/bootloader.   AFAIK U-Boot doesn't support DT
overlays.

Kuba

[U-Boot] dtoverlay for mx6 ARM

[Johann Obermayr]

Am 11.06.2015 um 22:13 schrieb Jakub Kici?ski:
> On Thu, 11 Jun 2015 21:49:57 +0200, Johann Obermayr wrote:
>> Hello,
> Hi there,
>   
>> for raspberyy pi there are some "features" available.
>> dtoverlay, dtparam, ...
>> we have a Freescale mx6 CPU.
>> How we can add/enable this features ?
> I'm new to U-Boot but on RPi the "features" are provided by their
> proprietary firmware/bootloader.   AFAIK U-Boot doesn't support DT
> overlays.
>
> Kuba
>
Thank you for this information.

Is there a way to change a loaded devicetree configuration ?

Because we have many boards with small differents. but less memory on disk.
at this time one DTB file need ~150kb. we have 1MB free, but we have > 
20 different boards and
every month 1 or 2 new boards.

regards
   Johann

[U-Boot] dtoverlay for mx6 ARM

[Jakub Kiciński]

On Fri, 12 Jun 2015 00:14:17 +0200, Johann Obermayr wrote:
> Am 11.06.2015 um 22:13 schrieb Jakub Kici?ski:
> > On Thu, 11 Jun 2015 21:49:57 +0200, Johann Obermayr wrote:
> >> Hello,
> > Hi there,
> >   
> >> for raspberyy pi there are some "features" available.
> >> dtoverlay, dtparam, ...
> >> we have a Freescale mx6 CPU.
> >> How we can add/enable this features ?
> > I'm new to U-Boot but on RPi the "features" are provided by their
> > proprietary firmware/bootloader.   AFAIK U-Boot doesn't support DT
> > overlays.
> Thank you for this information.
> 
> Is there a way to change a loaded devicetree configuration ?
> 
> Because we have many boards with small differents. but less memory on disk.
> at this time one DTB file need ~150kb. we have 1MB free, but we have > 
> 20 different boards and
> every month 1 or 2 new boards.

Ugh, nothing comes to my mind, but as I said, I'm a newbie.  Maybe
someone else can chime in.

[U-Boot] dtoverlay for mx6 ARM

[Michal Suchanek]

Hello,

On 12 June 2015 at 00:14, Johann Obermayr <johann.obermayr@sigmatek.at> wrote:
> Am 11.06.2015 um 22:13 schrieb Jakub Kici?ski:
>>
>> On Thu, 11 Jun 2015 21:49:57 +0200, Johann Obermayr wrote:
>>>
>>> Hello,
>>
>> Hi there,
>>
>>>
>>> for raspberyy pi there are some "features" available.
>>> dtoverlay, dtparam, ...
>>> we have a Freescale mx6 CPU.
>>> How we can add/enable this features ?
>>
>> I'm new to U-Boot but on RPi the "features" are provided by their
>> proprietary firmware/bootloader.   AFAIK U-Boot doesn't support DT
>> overlays.
>>
>> Kuba
>>
> Thank you for this information.
>
> Is there a way to change a loaded devicetree configuration ?
>
> Because we have many boards with small differents. but less memory on disk.
> at this time one DTB file need ~150kb. we have 1MB free, but we have > 20
> different boards and
> every month 1 or 2 new boards.

This depends on the changes you want.

If the change is in a part of the DT which you do not need to boot you
can just leave that part out and build overlay bits which you load at
runtime in your init scripts (needs kernel and dtc patches).

If the changes are required to boot there is some support in u-boot to
modify DTs but I am not sure how much functionality is desirable and
already implemented. Currently simplefb depends on u-boot modifying
pre-made DT nodes.

Thanks

Michal