[PATCH] ARM: Allow MULTIPLATFORM to select XIP

On Thu, 18 Feb 2016, Chris Brandt wrote:

quoted

And realistically it makes no sense to use XIP (surely because you need
to save space) and have multi-platform support in your kernel.

The problem is that you don't have a choice: Multi-platform is your only choice for many devices (MMU devices that is).

So for XIP, it comes down to either:

A) Go back to making individual configs for each MPU

B) Let everything keep getting grouped together into multi-platform, and then just de-selecting the MPU you don't want.

I can tell you when I build my upstream XIP kernel for testing for the RZ/A1, it's ARCH_MULTIPLATFORM (all Renesas parts are multiplatform) and then remove everything I don't want/need, my kernel size is 3.4MB.

quoted

IMHO it should be clear that with XIP there is only one platform that can
be supported.

I would be fine if there was some way you could only select XIP_KERNEL 
if only 1 of the MPUs in the multiplatform group were selected...but I 
can't figure out how to do that in the kbuild system (without adding 
lots of chunky configs all over the place...which is not what I want)

Is there some way you can do a PLATFORM_COUNTER++ for each device that 
is selected, and then XIP_KERNEL would depend on PLATFORM_COUNTER == 1 
?

I don't know all the Kconfig possibilities.

But would something like this work?

config FOO
	depends on !(XIP && CHOICE_MADE)
	select CHOICE_MADE

?


Nicolas