arm64: build with baremetal linker target instead of Linux when available

Not all toolchains have the baremetal elf targets, RedHat/Fedora ones
in particular. So, probe for whether it's available and use the previous
(linux) targets if it isn't.

Reported-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Kocialkowski <contact@paulk.fr>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 45272266dafb64a1fda433e7f557bf11b89e908e..99a1d859b8b89e9f54d6310eff913af14e499e41 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -60,15 +60,16 @@ ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 KBUILD_CPPFLAGS        += -mbig-endian
 CHECKFLAGS     += -D__AARCH64EB__
 AS             += -EB
-LD             += -EB
-LDFLAGS                += -maarch64linuxb
+# Prefer the baremetal ELF build target, but not all toolchains include
+# it so fall back to the standard linux version if needed.
+LDFLAGS                += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
 UTS_MACHINE    := aarch64_be
 else
 KBUILD_CPPFLAGS        += -mlittle-endian
 CHECKFLAGS     += -D__AARCH64EL__
 AS             += -EL
-LD             += -EL
-LDFLAGS                += -maarch64linux
+# Same as above, prefer ELF but fall back to linux target if needed.
+LDFLAGS                += -EL $(call ld-option, -maarch64elf, -maarch64linux)
 UTS_MACHINE    := aarch64
 endif
 

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index c8156d61678cfbc6907a9176efbccb03aa8387ce..1e13f502b42fde520e6062d2ef64ca76fc0f91ae 100644 (file)
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -163,8 +163,8 @@ cc-ldoption = $(call try-run,\
        $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # ld-option
-# Usage: LDFLAGS += $(call ld-option, -X)
-ld-option = $(call try-run, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2))
+# Usage: LDFLAGS += $(call ld-option, -X, -Y)
+ld-option = $(call try-run, $(LD) $(LDFLAGS) $(1) -v,$(1),$(2),$(3))
 
 # ar-option
 # Usage: KBUILD_ARFLAGS := $(call ar-option,D)