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Diffstat (limited to 'drivers/firmware/efi/libstub/Makefile')
-rw-r--r--drivers/firmware/efi/libstub/Makefile41
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
new file mode 100644
index 000000000..280bc0a63
--- /dev/null
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -0,0 +1,41 @@
+#
+# 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__ $(LINUX_INCLUDE) -O2 \
+ -fPIC -fno-strict-aliasing -mno-red-zone \
+ -mno-mmx -mno-sse -DDISABLE_BRANCH_PROFILING
+
+cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS))
+cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
+ -fno-builtin -fpic -mno-single-pic-base
+
+KBUILD_CFLAGS := $(cflags-y) \
+ $(call cc-option,-ffreestanding) \
+ $(call cc-option,-fno-stack-protector)
+
+GCOV_PROFILE := n
+KASAN_SANITIZE := n
+
+lib-y := efi-stub-helper.o
+lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o
+
+CFLAGS_fdt.o += -I$(srctree)/scripts/dtc/libfdt/
+
+#
+# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
+# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
+# So let's apply the __init annotations at the section level, by prefixing
+# the section names directly. This will ensure that even all the inline string
+# literals are covered.
+#
+extra-$(CONFIG_ARM64) := $(lib-y)
+lib-$(CONFIG_ARM64) := $(patsubst %.o,%.init.o,$(lib-y))
+
+OBJCOPYFLAGS := --prefix-alloc-sections=.init
+$(obj)/%.init.o: $(obj)/%.o FORCE
+ $(call if_changed,objcopy)