[Buildroot] [PATCH 03/14] RESEND: handle MMU configuration

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

On Fri, Oct 09, 2009 at 01:22:44PM +0200, Peter Korsgaard wrote:
>>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:
>
> Thomas> Le Wed,  7 Oct 2009 23:27:47 +0200,
> Thomas> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> a ?crit :
>
> >> +config BR2_HAVE_NOMMU
> >> +	def_bool n
> >> +	# assume that we have an MMU per default.
>
> Thomas> Maybe we should use BR2_HAVE_MMU, def_bool y. The
> Thomas> non-not-negative-if-not-options are really hard to understand.
>
>I guess the idea is that the architectures can 'select' this option
>behind the user's back. There's afaik nothing in kconfig to disable

Exactly. e.g.:
$ grep -B3 HAVE_NOMMU target/Config.in.arch 

config BR2_m68k_cpu_68000
	bool "68000"
	select BR2_HAVE_NOMMU
config BR2_m68k_cpu_68010
	bool "68010"
	select BR2_HAVE_NOMMU
--

config BR2_m68k_cpu_coldfire_51qe
	bool "51qe"
	select BR2_HAVE_NOMMU
config BR2_m68k_cpu_coldfire_5202
	bool "5202"
	select BR2_HAVE_NOMMU
config BR2_m68k_cpu_coldfire_5204
	bool "5204"
	select BR2_HAVE_NOMMU
config BR2_m68k_cpu_coldfire_5206
	bool "5206"
	select BR2_HAVE_NOMMU

>another option if you enable something.
>
>You could ofcourse move the logic here instead of in the individual arch
>handling (E.G. default y if BR2_ARCH_bfin, or what it now is).
>
> >> +config BR2_USE_MMU
> >> +	bool "Use MMU"
> >> +	default y
> >> +	depends on !BR2_HAVE_NOMMU
> >> +	help
> >> +	  If your target has an MMU and you want to use it
> >> +	  then say Y here.
>
> Thomas> What's the usage of these two new options ?
>
>Yes, I would like to know this as well. I would imagine properly
>supporting nommu would take quite some more effort than this (E.G. most
>packages should get hidden).

why would you want to hide most of the package?
For a start, it only affects the binary format.