[OpenRISC] [PATCH v3 3/3] or1k: gcc: initial support for openrisc

Stafford Horne
2018-11-05T20:52:40Z

On Mon, Nov 05, 2018 at 11:13:53AM +0000, Szabolcs Nagy wrote:
> On 04/11/18 09:05, Stafford Horne wrote:
> > On Mon, Oct 29, 2018 at 02:28:11PM +0000, Szabolcs Nagy wrote:
> >> On 27/10/18 05:37, Stafford Horne wrote:
> ...
> >>> +#undef LINK_SPEC
> >>> +#define LINK_SPEC "%{h*} \
> >>> + %{static:-Bstatic} \
> >>> + %{shared:-shared} \
> >>> + %{symbolic:-Bsymbolic} \
> >>> + %{!static: \
> >>> + %{rdynamic:-export-dynamic} \
> >>> + %{!shared:-dynamic-linker " GNU_USER_DYNAMIC_LINKER "}}"
> >>> +
> >>> +#endif /* GCC_OR1K_LINUX_H */
> >>
> >> note that because of the -static-pie mess each
> >> target needs a more complicated LINK_SPEC now.
> >
> > Hello,
> >
> > Does something like this look better?
> >
> > --- a/gcc/config/or1k/linux.h
> > +++ b/gcc/config/or1k/linux.h
> > @@ -37,8 +37,9 @@
> > %{static:-Bstatic} \
> > %{shared:-shared} \
> > %{symbolic:-Bsymbolic} \
> > - %{!static: \
> > + %{!static:%{!static-pie: \
> > %{rdynamic:-export-dynamic} \
> > - %{!shared:-dynamic-linker " GNU_USER_DYNAMIC_LINKER "}}"
> > + %{!shared:-dynamic-linker " GNU_USER_DYNAMIC_LINKER "}}} \
> > + %{static-pie:-Bstatic -pie --no-dynamic-linker -z text}"
> >
> > #endif /* GCC_OR1K_LINUX_H */
>
> looks ok.
>
> > I have tested this out with or1k-linux-musl, but I get some LD complaints i.e.
> >
> > .../or1k-linux-musl/bin/ld: .../or1k-linux-musl/lib/libc.a(exit.o): non-pic relocation against symbol __fini_array_end
> > .../or1k-linux-musl/bin/ld: .../or1k-linux-musl/lib/libc.a(exit.o): non-pic relocation against symbol __fini_array_start
> >
> > Those are some warnings we recently added to LD, perhaps I need to rebuild the
> > libc.a with PIE as well. I will try it out, but if anyone has some suggestions
> > that would be helpful.
>
> yes, musl does not build libc.a with pic by default,
> either use a gcc configured with --enable-default-pie
> or CC='gcc -fPIC' when building musl.
>
> after that -static-pie linking should work.
>
> (maybe musl should have an --enable-static-pie config
> option to make this simpler)

Thank's for confirming. I tested this out with your tips and it works.

I use musl-cross-make [0] to build musl, all you really need to do is add
'GCC_CONFIG += --enable-default-pie' to your config.mak file.

-Stafford

[0] https://github.com/richfelker/musl-cross-make