[deliverable/linux.git] / drivers / firmware / efi / libstub / Makefile

#
# The stub may be linked into the kernel proper or into a separate boot binary,
# but in either case, it executes before the kernel does (with MMU disabled) so
# things like ftrace and stack-protector are likely to cause trouble if left
# enabled, even if doing so doesn't break the build.
#
cflags-$(CONFIG_X86_32)		:= -march=i386
cflags-$(CONFIG_X86_64)		:= -mcmodel=small
cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 \
				   -fPIC -fno-strict-aliasing -mno-red-zone \
				   -mno-mmx -mno-sse

cflags-$(CONFIG_ARM64)		:= $(subst -pg,,$(KBUILD_CFLAGS))
cflags-$(CONFIG_ARM)		:= $(subst -pg,,$(KBUILD_CFLAGS)) \
				   -fno-builtin -fpic -mno-single-pic-base

cflags-$(CONFIG_EFI_ARMSTUB)	+= -I$(srctree)/scripts/dtc/libfdt

KBUILD_CFLAGS			:= $(cflags-y) -DDISABLE_BRANCH_PROFILING \
				   $(call cc-option,-ffreestanding) \
				   $(call cc-option,-fno-stack-protector)

GCOV_PROFILE			:= n
KASAN_SANITIZE			:= n
UBSAN_SANITIZE			:= n

lib-y				:= efi-stub-helper.o

# include the stub's generic dependencies from lib/ when building for ARM/arm64
arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c

$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
	$(call if_changed_rule,cc_o_c)

lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o string.o \
				   $(patsubst %.c,lib-%.o,$(arm-deps))

lib-$(CONFIG_ARM)		+= arm32-stub.o
lib-$(CONFIG_ARM64)		+= arm64-stub.o
CFLAGS_arm64-stub.o 		:= -DTEXT_OFFSET=$(TEXT_OFFSET)

#
# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
# So let's apply the __init annotations at the section level, by prefixing
# the section names directly. This will ensure that even all the inline string
# literals are covered.
# The fact that the stub and the kernel proper are essentially the same binary
# also means that we need to be extra careful to make sure that the stub does
# not rely on any absolute symbol references, considering that the virtual
# kernel mapping that the linker uses is not active yet when the stub is
# executing. So build all C dependencies of the EFI stub into libstub, and do
# a verification pass to see if any absolute relocations exist in any of the
# object files.
#
extra-$(CONFIG_EFI_ARMSTUB)	:= $(lib-y)
lib-$(CONFIG_EFI_ARMSTUB)	:= $(patsubst %.o,%.stub.o,$(lib-y))

STUBCOPY_FLAGS-y		:= -R .debug* -R *ksymtab* -R *kcrctab*
STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
				   --prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS

$(obj)/%.stub.o: $(obj)/%.o FORCE
	$(call if_changed,stubcopy)

quiet_cmd_stubcopy = STUBCPY $@
      cmd_stubcopy = if $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; then	\
		     $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y)	\
		     && (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
			 rm -f $@; /bin/false); else /bin/false; fi

#
# ARM discards the .data section because it disallows r/w data in the
# decompressor. So move our .data to .data.efistub, which is preserved
# explicitly by the decompressor linker script.
#
STUBCOPY_FLAGS-$(CONFIG_ARM)	+= --rename-section .data=.data.efistub
STUBCOPY_RELOC-$(CONFIG_ARM)	:= R_ARM_ABS
Commit	Line	Data
f4f75ad5 AB	1	#
	2	# The stub may be linked into the kernel proper or into a separate boot binary,
	3	# but in either case, it executes before the kernel does (with MMU disabled) so
	4	# things like ftrace and stack-protector are likely to cause trouble if left
	5	# enabled, even if doing so doesn't break the build.
	6	#
	7	cflags-$(CONFIG_X86_32) := -march=i386
	8	cflags-$(CONFIG_X86_64) := -mcmodel=small
	9	cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 \
	10	-fPIC -fno-strict-aliasing -mno-red-zone \
b523e185	11	-mno-mmx -mno-sse
f4f75ad5 AB	12
	13	cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS))
	14	cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
	15	-fno-builtin -fpic -mno-single-pic-base
	16
e8f3010f AB	17	cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt
e8f3010f AB	18
b523e185	19	KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
f4f75ad5 AB	20	$(call cc-option,-ffreestanding) \
	21	$(call cc-option,-fno-stack-protector)
	22
	23	GCOV_PROFILE := n
0b24becc	24	KASAN_SANITIZE := n
c6d30853	25	UBSAN_SANITIZE := n
f4f75ad5 AB	26
f4f75ad5 AB	27	lib-y := efi-stub-helper.o
e8f3010f AB	28
	29	# include the stub's generic dependencies from lib/ when building for ARM/arm64
	30	arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
	31
	32	$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
	33	$(call if_changed_rule,cc_o_c)
	34
	35	lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \
	36	$(patsubst %.c,lib-%.o,$(arm-deps))
f4f75ad5	37
81a0bc39	38	lib-$(CONFIG_ARM) += arm32-stub.o
bf457786 AB	39	lib-$(CONFIG_ARM64) += arm64-stub.o
	40	CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
	41
ddeeefe2 AB	42	#
	43	# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
	44	# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
	45	# So let's apply the __init annotations at the section level, by prefixing
	46	# the section names directly. This will ensure that even all the inline string
	47	# literals are covered.
e8f3010f AB	48	# The fact that the stub and the kernel proper are essentially the same binary
	49	# also means that we need to be extra careful to make sure that the stub does
	50	# not rely on any absolute symbol references, considering that the virtual
	51	# kernel mapping that the linker uses is not active yet when the stub is
	52	# executing. So build all C dependencies of the EFI stub into libstub, and do
	53	# a verification pass to see if any absolute relocations exist in any of the
	54	# object files.
ddeeefe2	55	#
e8f3010f AB	56	extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y)
	57	lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y))
	58
f8f8bdc4	59	STUBCOPY_FLAGS-y := -R .debug* -R ksymtab -R kcrctab
e8f3010f AB	60	STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
	61	--prefix-symbols=__efistub_
	62	STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS
	63
	64	$(obj)/%.stub.o: $(obj)/%.o FORCE
	65	$(call if_changed,stubcopy)
ddeeefe2	66
e8f3010f AB	67	quiet_cmd_stubcopy = STUBCPY $@
	68	cmd_stubcopy = if $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; then \
	69	$(OBJDUMP) -r $@ \| grep $(STUBCOPY_RELOC-y) \
	70	&& (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
	71	rm -f $@; /bin/false); else /bin/false; fi
81a0bc39 RF	72
	73	#
	74	# ARM discards the .data section because it disallows r/w data in the
	75	# decompressor. So move our .data to .data.efistub, which is preserved
	76	# explicitly by the decompressor linker script.
	77	#
	78	STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub
	79	STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS