Re: [patches] [PATCH] RISC-V: Support built-in dtb

[Palmer Dabbelt]

On Thu, 21 Dec 2017 12:43:20 PST (-0800), Arnd Bergmann wrote:
> On Thu, Dec 21, 2017 at 9:32 PM, Palmer Dabbelt <palmer@xxxxxxxxxx> wrote:
> > On Wed, 20 Dec 2017 01:14:31 PST (-0800), zongbox@xxxxxxxxx wrote:
>
> > I've added Arnd and Olof, in case they have a bit more perspective here.  If
> > I'm reading this correctly, there isn't an arm or arm64 option to do this.
> > There is an option to built in many DTBs, which makes a lot more sense to me
> > as it doesn't tie the kernel to any one particular implementation.  We'd
> > need a mechanism for picking the DTB that Linux should use.  We've kicked
> > around the idea of:
> >
> > * Having the bootloader always provide a DTB.
> > * Taking a hash of that DTB when booting Linux.
> > * Using that hash to look up DTBs that are built in to Linux.
> >
> > This would allow us to support replacing broken DTBs if they escape into the
> > wild, but would still allow us to have a portable kernel.
>
> Having an embedded DTB is only necessary for platforms with a legacy bootloader
> that doesn't understand DT at all, you should never need that here.
>
> I would suggest to require each bootloader to provide a way to replace the DTB
> with one that gets installed alongside the kernel.

Sounds good to me.