Re: [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain

From: Nick Desaulniers
Date: Mon Apr 13 2020 - 15:22:07 EST


On Fri, Apr 10, 2020 at 2:56 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Fri, Apr 10, 2020 at 1:28 AM Jian Cai <caij2003@xxxxxxxxx> wrote:
> >
> > iwmmxt.S contains XScale instructions LLVM ARM backend does not support.
> > Skip this file if LLVM integrated assemmbler or LLD is used to build ARM
> > kernel.
> >
> > Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
>
> It clearly makes sense to limit the Kconfig option to compilers that
> can actually build it.
> A few questions though:
>
> - Given that Armada XP with its PJ4B was still marketed until fairly
> recently[1],
> wouldn't it make sense to still add support for it? Is it a lot of work?

Sorry, can you help me verify from that link that PJ4B uses XSCALE? I
didn't see references to either in the link provided. Also, given the
history of XSCALE as noted by Russell, I'm surprised to see Marvell in
the mix.

>
> - Why does the linker have to understand it, rather than just the assembler?

It doesn't, just the assembler is the problem.

>
> [1] http://web.archive.org/web/20191015165247/https://www.marvell.com/embedded-processors/armada/index.jsp



--
Thanks,
~Nick Desaulniers