[PATCH RESEND] ARM: add dtbImage.<dt> and dtbuImage.<dt> rules

[Russell King - ARM Linux]

On Tue, Sep 24, 2013 at 08:01:52AM -0400, Jason Cooper wrote:
> On Tue, Sep 24, 2013 at 12:55:19PM +0200, Gerlando Falauto wrote:
> > So it shouldn't be such a crazy idea to create a dtbuImage.<dtb>
> > within Kbuild (as opposed to from an external wrapper for make).
> 
> Yes :)  The problem is that we are moving to multiplatform zImages.  In
> that scenario, the uImage target isn't very helpful because it needs to
> be custom to each board.  Additionally, appended-dtb was intended as a
> developer tool and isn't intended as a deployable item.  It also
> defeats the purpose of multiplatform.

And we've already taken the decision that we will not be augmenting
kbuild with any more ubooot specific stuff, especially with anything
that goes against the long term goal of having a single kernel image
which is bootable across multiple platforms.

Having kbuild wrap the zImage + DTB up into a uImage goes directly
against this goal, because it turns the produced kernel into something
which is specific to a single target.  It's much worse than what we
had before we went to DT, because with this it can only be used on a
_single_ target, whereas prior to DT we could boot a single kernel
on a variety of compatible targets.

Moreover, the support for appending the DTB to the zImage is a stop-gap
solution for the transition to a full DT based environment - don't
expect it to be around into the long term future.  Modern platforms
should be using a DT compatible boot loader, which means you don't
want to use the DTB appended to zImage method.