android_kernel_oneplus_msm8998/arch/arm64/Makefile
Greg Hackmann 69669503eb arm64: remove no-op -p linker flag
(commit 1a381d4a0a9a0f999a13faaba22bf6b3fc80dcb9 upstream)

Linking the ARM64 defconfig kernel with LLVM lld fails with the error:

  ld.lld: error: unknown argument: -p
  Makefile:1015: recipe for target 'vmlinux' failed

Without this flag, the ARM64 defconfig kernel successfully links with
lld and boots on Dragonboard 410c.

After digging through binutils source and changelogs, it turns out that
-p is only relevant to ancient binutils installations targeting 32-bit
ARM.  binutils accepts -p for AArch64 too, but it's always been
undocumented and silently ignored.  A comment in
ld/emultempl/aarch64elf.em explains that it's "Only here for backwards
compatibility".

Since this flag is a no-op on ARM64, we can safely drop it.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-01 09:46:36 +01:00

127 lines
3.5 KiB
Makefile

#
# arch/arm64/Makefile
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies.
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1995-2001 by Russell King
LDFLAGS_vmlinux :=--no-undefined -X
CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
OBJCOPYFLAGS :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
GZFLAGS :=-9
KBUILD_DEFCONFIG := defconfig
# Check for binutils support for specific extensions
lseinstr := $(call as-instr,.arch_extension lse,-DCONFIG_AS_LSE=1)
ifeq ($(CONFIG_ARM64_LSE_ATOMICS), y)
ifeq ($(lseinstr),)
$(warning LSE atomics not supported by binutils)
endif
endif
KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr)
KBUILD_CFLAGS += $(call cc-option, -mpc-relative-literal-loads)
KBUILD_AFLAGS += $(lseinstr)
ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
KBUILD_CPPFLAGS += -mbig-endian
AS += -EB
LD += -EB
else
KBUILD_CPPFLAGS += -mlittle-endian
AS += -EL
LD += -EL
endif
CHECKFLAGS += -D__aarch64__
ifeq ($(CONFIG_ARM64_ERRATUM_843419), y)
KBUILD_CFLAGS_MODULE += -mcmodel=large
endif
# Default value
head-y := arch/arm64/kernel/head.o
# The byte offset of the kernel image in RAM from the start of RAM.
ifeq ($(CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET), y)
TEXT_OFFSET := $(shell awk 'BEGIN {srand(); printf "0x%03x000\n", int(512 * rand())}')
else
TEXT_OFFSET := 0x00080000
endif
ifeq ($(cc-name),clang)
KBUILD_CFLAGS += $(call cc-disable-warning, asm-operand-widths)
endif
# KASAN_SHADOW_OFFSET = VA_START + (1 << (VA_BITS - 3)) - (1 << 61)
# in 32-bit arithmetic
KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \
(0xffffffff & (-1 << ($(CONFIG_ARM64_VA_BITS) - 32))) \
+ (1 << ($(CONFIG_ARM64_VA_BITS) - 32 - 3)) \
- (1 << (64 - 32 - 3)) )) )
export TEXT_OFFSET GZFLAGS
core-y += arch/arm64/kernel/ arch/arm64/mm/
core-$(CONFIG_NET) += arch/arm64/net/
core-$(CONFIG_KVM) += arch/arm64/kvm/
core-$(CONFIG_XEN) += arch/arm64/xen/
core-$(CONFIG_CRYPTO) += arch/arm64/crypto/
libs-y := arch/arm64/lib/ $(libs-y)
core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
# Default target when executing plain make
KBUILD_IMAGE := Image.gz
KBUILD_DTBS := dtbs
all: $(KBUILD_IMAGE) $(KBUILD_DTBS)
boot := arch/arm64/boot
Image: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
Image.%: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
zinstall install: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $@
%.dtb: scripts
$(Q)$(MAKE) $(build)=$(boot)/dts $(boot)/dts/$@
PHONY += dtbs dtbs_install
dtbs: prepare scripts
$(Q)$(MAKE) $(build)=$(boot)/dts
dtbs_install:
$(Q)$(MAKE) $(dtbinst)=$(boot)/dts
PHONY += vdso_install
vdso_install:
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
# We use MRPROPER_FILES and CLEAN_FILES now
archclean:
$(Q)$(MAKE) $(clean)=$(boot)
$(Q)$(MAKE) $(clean)=$(boot)/dts
define archhelp
echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
echo '* dtbs - Build device tree blobs for enabled boards'
echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'
echo ' install - Install uncompressed kernel'
echo ' zinstall - Install compressed kernel'
echo ' Install using (your) ~/bin/installkernel or'
echo ' (distribution) /sbin/installkernel or'
echo ' install to $$(INSTALL_PATH) and run lilo'
endef