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

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

	$(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)