Re: [RFC PATCH v2 09/31] kvx: Add build infrastructure

From: Jules Maselbas
Date: Fri Jan 20 2023 - 10:03:52 EST


On Fri, Jan 20, 2023 at 04:01:11PM +0100, Arnd Bergmann wrote:
> On Fri, Jan 20, 2023, at 15:53, Jules Maselbas wrote:
> > On Fri, Jan 20, 2023 at 03:39:22PM +0100, Arnd Bergmann wrote:
> >> On Fri, Jan 20, 2023, at 15:09, Yann Sionneau wrote:
> >> > - Fix clean target raising an error from gcc (LIBGCC)
> >>
> >> I had not noticed this on v1 but:
> >>
> >> > +# Link with libgcc to get __div* builtins.
> >> > +LIBGCC := $(shell $(CC) $(DEFAULT_OPTS) --print-libgcc-file-name)
> >>
> >> It's better to copy the bits of libgcc that you actually need
> >> than to include the whole thing. The kernel is in a weird
> > It was initialy using KCONFIG_CFLAGS which do not contains valid options
> > when invoking the clean target.
> >
> > I am not exactly sure what's needed by gcc for --print-libgcc-file-name,
> > my guess is that only the -march option matters, I will double check
> > internally with compiler peoples.
> >
> >> state that is neither freestanding nor the normal libc based
> >> environment, so we generally want full control over what is
> >> used. This is particularly important for 32-bit architectures
> >> that do not want the 64-bit division, but there are probably
> >> enough other cases as well.
>
> To clarify: I meant you should not include libgcc.a at all but
> add the minimum set of required files as arch/kvx/lib/*.S.
Thanks for clarifying :)


-- Jules