[U-Boot] [PATCH v3 10/10] kconfig: move CONFIG_DEFAULT_DEVICE_TREE to kconfig

[Simon Glass]

Hi Masahiro,

On 25 September 2014 02:06, Masahiro Yamada <yamada.m at jp.panasonic.com> wrote:
> Hi Simon,
>
>
>
> On Wed, 24 Sep 2014 17:09:35 -0600
> Simon Glass <sjg at chromium.org> wrote:
>> >
>> > diff --git a/configs/am335x_boneblack_vboot_defconfig b/configs/am335x_boneblack_vboot_defconfig
>> > index af7ceca..e257143 100644
>> > --- a/configs/am335x_boneblack_vboot_defconfig
>> > +++ b/configs/am335x_boneblack_vboot_defconfig
>> > @@ -3,3 +3,4 @@ CONFIG_SYS_EXTRA_OPTIONS="SERIAL1,CONS_INDEX=1,EMMC_BOOT,ENABLE_VBOOT"
>> >  +S:CONFIG_ARM=y
>> >  +S:CONFIG_TARGET_AM335X_EVM=y
>> >  CONFIG_OF_CONTROL=y
>> > +CONFIG_DEFAULT_DEVICE_TREE="am335x-boneblack"
>>
>> Do we want to include this for SPL too? At some point we might support
>> this. But if you want to define it only for U-Boot, that's OK.
>>
>> Regards,
>
>
>
> I was planning to expand this for SPL in the future,
> but if you want to do that now, I am fine with it.
>
> (The series is just moving CONFIGs verbatim from headers to defconfigs)
>
>
> I am afraid the current SPL implementation is too special.
>
>  - special Makefile (scripts/Makefile.spl)
>  - special linker scripts  (u-boot-spl.lds)
>  - special boot sequence (common/spl/spl.c)
>
> etc.  We need extra efforts because of that.
>
>
> My long-term goal is to implement the normal image and the SPL image
> as more symetirical ones, and I hope CONFIG_SPL_* will go away eventually.
>
>
> If we had implemented SPL as a generic case, you would not have needed
> a separate work for CONFIG_SPL_DM, right?
> Perhaps, you would have implemented the Driver Model for both of the normal and SPL
> in the first place (and just enable CONFIG_DM for SPL and it would work).
>
> But unfortunately, we don't.
> Nor can I do that now.
> I guess we need more refactoring.
>
>
> If the device tree control for SPL is urgent necessity,
> I am fine with CONFIG_SPL_OF_CONTROL like before, or another implementation.
>
>
> Comments are welcome on this issue, of course.

Yes SPL should become less special, all of this sounds good.

With the DM SPL series we are getting close to just being able to
enable FDT in SPL just like any other feature. I'm not planning to
look at that imminently though as the DM SPL stuff is still pretty
new.

Note that the reason for CONFIG_SPL_DM is mostly a migration exercise.
It allows boards to decide when they are ready to switch to DM. I
expect the option will be removed one day (since boards with SPL are
mostly the well maintained ones I think).

Regards,
Simon