Re: [RFC] [PATCH] x86: Use ELF section to list CPU vendor specificcode (Linux Tiny)

From: Matt Mackall
Date: Fri Feb 22 2008 - 21:44:37 EST



On Fri, 2008-02-15 at 12:00 +0100, Thomas Petazzoni wrote:
> Hi,
>
> Le Mon, 11 Feb 2008 16:54:30 -0800,
> "H. Peter Anvin" <hpa@xxxxxxxxx> a Ãcrit :
>
> > b) would be my first choice, and yes, it would be a good thing to
> > have a generalized mechanism for this. For the registrant, it's
> > pretty easy: just add a macro that adds a pointer to a named
> > section. We then need a way to get the base address and length of
> > each such section in order to be able to execute each function in
> > sequence.
>
> You'll find below a tentative patch that implements this. Tuple
> (vendor, pointer to cpu_dev structure) are stored in a
> x86cpuvendor.init section of the kernel, which is then read by the
> generic CPU code in arch/x86/kernel/cpu/common.c to fill the cpu_devs[]
> function.

This is not quite what Peter and I were thinking of, I think. It's not
at all generic. How about a section that simply contains a set of
function pointers, a macro to add things to that section, and a function
that calls all the pointers in that section. Eg:

CALLBACK_SECTION(init_cpu_amd, "cpuvendor.init");
invoke_callback_section("cpuvendor.init");

..which would give us a generic facility we could use in various places.

--
Mathematics is the supreme nostalgia of our time.

--
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/