[PATCH -fixes] riscv: Fix BUILTIN_DTB for sifive and microchip soc

[Arnd Bergmann]

On Sat, Jun 5, 2021 at 8:37 AM Alex Ghiti <alex at ghiti.fr> wrote:
> Le 4/06/2021 à 15:08, Arnd Bergmann a écrit :
> > On Fri, Jun 4, 2021 at 2:06 PM Alexandre Ghiti <alex at ghiti.fr> wrote:
> >>
> >> Fix BUILTIN_DTB config which resulted in a dtb that was actually not built
> >> into the Linux image: in the same manner as Canaan soc does, create an object
> >> file from the dtb file that will get linked into the Linux image.
> >>
> >> Signed-off-by: Alexandre Ghiti <alex at ghiti.fr>
> >
> > Along the same lines as the comment that Jisheng Zhang made on the fixed
> > address, building a dtb into the kernel itself fundamentally breaks generic
> > kernel images.
> >
> > I can understand using it on K210, which is extremely limited and wouldn't
> > run a generic kernel anyway, but for normal platforms like microchip and
> > sifive, it would be better to disallow CONFIG_BUILTIN_DTB in Kconfig
> > and require a non-broken boot loader.
>
> I kind of disagree because if I want to build a custom kernel for those
> platforms with a builtin dtb for some reasons (debug, development..Etc),
> I think I should be able to do so.

How is the builtin dtb better than appended dtb, or passing the dtb to the
boot loader in that case?

         Arnd