[PATCH] ARM: nommu: re-enable use of vexpress without ARCH_MULTIPLATFORM

[Russell King - ARM Linux]

On Wed, Jan 09, 2013 at 02:39:36PM -0600, Rob Herring wrote:
> On 01/09/2013 02:22 PM, Arnd Bergmann wrote:
> > On Wednesday 09 January 2013, Nicolas Pitre wrote:
> >> On Wed, 9 Jan 2013, Arnd Bergmann wrote:
> >>
> >>> On a related topic, I still think we should fix ARCH_MULTI_V7 not
> >>> to select ARCH_VEXPRESS unconditionally and come up with a better
> >>> way to avoid having an empty platform list to make 'allnoconfig'
> >>> still work.
> >>
> >> The virtual guest platform support that Will and Marc did is small 
> >> enough that it could always be selected in place of vexpress.
> > 
> > But that only helps when ARMv7 is selected, unless we want to build
> > it only for ARMv4, v5 or v6 kernels.
> > 
> > Besides, the only reason we can't have a kernel without any platform
> > selected is that the linker script has code in it to intentionally
> > barf on that because it's guaranteed not to boot on any hardware.
> > 
> > If we decide that building an allnoconfig without any platform
> > is actually ok, we could just as well rip out that error statement.
> > 
> 
> That patch is already posted, but Russell doesn't like it as you can
> have a kernel that doesn't boot. You don't like the allno and randconfig
> failures, so we're stuck. I think there are dozens of config options
> that will make you not boot on any given platform, so failing to boot
> because you did not select your machine is a non-issue.

What I actually suggested is that we should be aiming for the DT side
of things to get to the point where DT is just another _single_ platform
as far as that code goes, and that DT should describe the hardware
sufficiently well that we don't have multiple machine_desc things to
select via DT - so a DT kernel would have exactly one machine_desc (or
maybe even zero! - with the linker script check conditional on !CONFIG_OF)

That then gets rid of the issue entirely.