Re: [PATCH 11/13] cell: split out board specific files

From: Segher Boessenkool
Date: Mon May 01 2006 - 19:10:10 EST


Segher, a problem with your suggestion is that our
makefiles don't have as rich a set of logical ops as the
config files. Its easy to express 'build A if B', but not
so easy to do 'build A if not C'. To make this work
cleanly I made PPC_CELL denote !SOME_HYPERVISOR_THING,
so I can have constructions like this in the makefile:

Not just that, but we can have a kernel image supporting both
the "raw" hardware _and_ stuff with a hypervisor underneath.

All CONFIG_<whatever> should always be used as a positive,
never a negative. My bad :-)

So it really should be

depends on PPC_CELL_NATIVE

or similar. Having PPC_CELL mean "native" / "raw" is not the
way to go, there will be many many hypervisors in the future,
it would be nice to have PPC_CELL mean just that, "support for
the Cell architecture" in general, kernels running on various
hypervisors will see the hardware virtualised to varying degrees.


Segher

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/