Re: kbuild question

[Sam Ravnborg <sam@ravnborg.org>]

> > 
> > Sure, on powerpc for some of the embedded sub-architectures you can only
> > select a single board to build for.  For a lot of people this is sufficient,
> > however we are moving towards a world where you can easily build in support
> > for multiple boards into a single kernel.
> > 
> > I'd like to have it such that if I'm only building support for one board
> > (CONFIG_ONLY_HAVE_ONE, not going to call it that, but for this discussion its
> > sufficient), you get a choice menu from Kconfig enforcing the ability to only
> > select one board.  However if !CONFIG_ONLY_HAVE_ONE than you can select
> > multiple boards to build into your kernel.
> > 
> > if CONFIG_ONLY_HAVE_ONE is set we can optimize out the runtime checks that get
> > added for handling the multiple board case.
> 
> On m68k we have the same problem, but what I'm what I'm considering is to 
> add a new mode for choice groups - at least one must be selected and 
> kconfig generates the extra information if only one is selected.

How about extendign the current 'option' syntax to do this?
So we could do something like:

choice
	prompt "choice prompt"
	default VAL_FIRST
	option multivalue if !CONFIG_ONLY_HAVE_ONE

config VAL_FIRST
	bool "first"

config VAL_SECOND
	bool "second"

endchoice

It seems to fit well with how option is used today, and extends current
syntax nicely.

	Sam