kernel/drivers/firmware/efi/libstub/Makefile

   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__ $(LINUX_INCLUDE) -O2 \
  10                                    -fPIC -fno-strict-aliasing -mno-red-zone \
  11                                    -mno-mmx -mno-sse -DDISABLE_BRANCH_PROFILING
  12
  13 cflags-$(CONFIG_ARM64)          := $(subst -pg,,$(KBUILD_CFLAGS))
  14 cflags-$(CONFIG_ARM)            := $(subst -pg,,$(KBUILD_CFLAGS)) \
  15                                    -fno-builtin -fpic -mno-single-pic-base
  16
  17 KBUILD_CFLAGS                   := $(cflags-y) \
  18                                    $(call cc-option,-ffreestanding) \
  19                                    $(call cc-option,-fno-stack-protector)
  20
  21 GCOV_PROFILE                    := n
  22 KASAN_SANITIZE                  := n
  23
  24 lib-y                           := efi-stub-helper.o
  25 lib-$(CONFIG_EFI_ARMSTUB)       += arm-stub.o fdt.o
  26
  27 CFLAGS_fdt.o                    += -I$(srctree)/scripts/dtc/libfdt/
  28
  29 #
  30 # arm64 puts the stub in the kernel proper, which will unnecessarily retain all
  31 # code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
  32 # So let's apply the __init annotations at the section level, by prefixing
  33 # the section names directly. This will ensure that even all the inline string
  34 # literals are covered.
  35 #
  36 extra-$(CONFIG_ARM64)           := $(lib-y)
  37 lib-$(CONFIG_ARM64)             := $(patsubst %.o,%.init.o,$(lib-y))
  38
  39 OBJCOPYFLAGS := --prefix-alloc-sections=.init
  40 $(obj)/%.init.o: $(obj)/%.o FORCE
  41         $(call if_changed,objcopy)