Re: [PATCH] dt-bindings: Add a RISC-V SBI firmware node

[Rob Herring]

On Mon, Nov 20, 2017 at 11:50:00AM -0800, Palmer Dabbelt wrote:
> The RISC-V privileged ISA mandates the presence of an SBI, but there's
> no reason not to put it in the device tree.  This would allow us to
> possibly remove the SBI later.

If it is mandatory, then it should not be in DT. DT is not a driver 
instantiation mechanism.

If your ISA can vary, I'd recommend you make that discoverable. DT is 
for what we failed to make discoverable.

Rob