Messages in this thread | | | Date | Wed, 10 Nov 2004 03:09:51 +0100 | From | Adrian Bunk <> | Subject | Re: kconfig/build question.. |
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On Wed, Nov 10, 2004 at 01:16:10AM +0000, Dave Airlie wrote: > > I've come across something that I'm not sure Kconfig can do but I'll > explain what I need and see what others can come up with... > > The DRM has a weak dependency on AGP, it does not require AGP for all > situations but can use it in most... > > So what I want to do and what I think Kbuild can't do is: > > if CONFIG_AGP=n then CONFIG_DRM can be n,m,y > if CONFIG_AGP=m then CONFIG_DRM can be m but not y > if CONFIG_AGP=y then CONFIG_DRM can be m,y >...
The second case is bad because enabling a module shouldn't change the static parts of the kernel [1].
Let me suggest a slightly different solution:
I assume a "weak dependency" dependency means you can enable some AGP specific code in the DRM code?
config DRM_AGP bool depends on ((DRM = "m" && AGP) || (DRM = "y" && AGP = "y")) default y
In the DRM code, you #ifdef CONFIG_DRM_AGP the AGP specific code.
This way, CONFIG_AGP=m and CONFIG_DRM=y is a legal configuration but doesn't enable the AGP specific code in the DRM code.
> Dave.
cu Adrian
[1] yes, this isn't always true in the current kernel
--
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