On 05/16/2018 08:03 AM, Alexey Brodkin wrote: > GCC built for arc*-*-linux has "-mmedium-calls" implicitly enabled by default > thus we don't see any problems during Linux kernel compilation. > ----------------------------->8------------------------ > arc-linux-gcc -mcpu=arc700 -Q --help=target | grep calls > -mlong-calls [disabled] > -mmedium-calls [enabled] > ----------------------------->8------------------------ > > But if we try to use so-called Elf32 toolchain with GCC configured for > arc*-*-elf* then we'd see the following failure: > ----------------------------->8------------------------ > init/do_mounts.o: In function 'init_rootfs': > do_mounts.c:(.init.text+0x108): relocation truncated to fit: R_ARC_S21W_PCREL > against symbol 'unregister_filesystem' defined in .text section in fs/filesystems.o > > arc-elf32-ld: final link failed: Symbol needs debug section which does not exist > make: *** [vmlinux] Error 1 > ----------------------------->8------------------------ > > That happens because neither "-mmedium-calls" nor "-mlong-calls" are enabled in > Elf32 GCC: > ----------------------------->8------------------------ > arc-elf32-gcc -mcpu=arc700 -Q --help=target | grep calls > -mlong-calls [disabled] > -mmedium-calls [disabled] > ----------------------------->8------------------------ > > Now to make it possible to use Elf32 toolchain for building Linux kernel > we're explicitly add "-mmedium-calls" to CFLAGS. > > Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com> > --- > arch/arc/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arc/Makefile b/arch/arc/Makefile > index d37f49d6a27f..db9ce90c3cc0 100644 > --- a/arch/arc/Makefile > +++ b/arch/arc/Makefile > @@ -16,7 +16,7 @@ endif > > KBUILD_DEFCONFIG := nsim_700_defconfig > > -cflags-y += -fno-common -pipe -fno-builtin -D__linux__ > +cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__ > cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7 > cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs LGTM. Bbut while we are here, can you now remove -mmedium-calls for specific files further down in the makefile.
