Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm
[sfrench/cifs-2.6.git] / drivers / firmware / efi / libstub / Makefile
1 # SPDX-License-Identifier: GPL-2.0
2 #
3 # The stub may be linked into the kernel proper or into a separate boot binary,
4 # but in either case, it executes before the kernel does (with MMU disabled) so
5 # things like ftrace and stack-protector are likely to cause trouble if left
6 # enabled, even if doing so doesn't break the build.
7 #
8 cflags-$(CONFIG_X86_32)         := -march=i386
9 cflags-$(CONFIG_X86_64)         := -mcmodel=small
10 cflags-$(CONFIG_X86)            += -m$(BITS) -D__KERNEL__ -O2 \
11                                    -fPIC -fno-strict-aliasing -mno-red-zone \
12                                    -mno-mmx -mno-sse
13
14 cflags-$(CONFIG_ARM64)          := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie
15 cflags-$(CONFIG_ARM)            := $(subst -pg,,$(KBUILD_CFLAGS)) \
16                                    -fno-builtin -fpic -mno-single-pic-base
17
18 cflags-$(CONFIG_EFI_ARMSTUB)    += -I$(srctree)/scripts/dtc/libfdt
19
20 KBUILD_CFLAGS                   := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
21                                    -D__NO_FORTIFY \
22                                    $(call cc-option,-ffreestanding) \
23                                    $(call cc-option,-fno-stack-protector)
24
25 GCOV_PROFILE                    := n
26 KASAN_SANITIZE                  := n
27 UBSAN_SANITIZE                  := n
28 OBJECT_FILES_NON_STANDARD       := y
29
30 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
31 KCOV_INSTRUMENT                 := n
32
33 lib-y                           := efi-stub-helper.o gop.o secureboot.o
34 lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o
35
36 # include the stub's generic dependencies from lib/ when building for ARM/arm64
37 arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
38 arm-deps-$(CONFIG_ARM64) += sort.c
39
40 $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
41         $(call if_changed_rule,cc_o_c)
42
43 lib-$(CONFIG_EFI_ARMSTUB)       += arm-stub.o fdt.o string.o random.o \
44                                    $(patsubst %.c,lib-%.o,$(arm-deps-y))
45
46 lib-$(CONFIG_ARM)               += arm32-stub.o
47 lib-$(CONFIG_ARM64)             += arm64-stub.o
48 CFLAGS_arm64-stub.o             := -DTEXT_OFFSET=$(TEXT_OFFSET)
49
50 #
51 # arm64 puts the stub in the kernel proper, which will unnecessarily retain all
52 # code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
53 # So let's apply the __init annotations at the section level, by prefixing
54 # the section names directly. This will ensure that even all the inline string
55 # literals are covered.
56 # The fact that the stub and the kernel proper are essentially the same binary
57 # also means that we need to be extra careful to make sure that the stub does
58 # not rely on any absolute symbol references, considering that the virtual
59 # kernel mapping that the linker uses is not active yet when the stub is
60 # executing. So build all C dependencies of the EFI stub into libstub, and do
61 # a verification pass to see if any absolute relocations exist in any of the
62 # object files.
63 #
64 extra-$(CONFIG_EFI_ARMSTUB)     := $(lib-y)
65 lib-$(CONFIG_EFI_ARMSTUB)       := $(patsubst %.o,%.stub.o,$(lib-y))
66
67 STUBCOPY_RM-y                   := -R *ksymtab* -R *kcrctab*
68 STUBCOPY_FLAGS-$(CONFIG_ARM64)  += --prefix-alloc-sections=.init \
69                                    --prefix-symbols=__efistub_
70 STUBCOPY_RELOC-$(CONFIG_ARM64)  := R_AARCH64_ABS
71
72 $(obj)/%.stub.o: $(obj)/%.o FORCE
73         $(call if_changed,stubcopy)
74
75 #
76 # Strip debug sections and some other sections that may legally contain
77 # absolute relocations, so that we can inspect the remaining sections for
78 # such relocations. If none are found, regenerate the output object, but
79 # this time, use objcopy and leave all sections in place.
80 #
81 quiet_cmd_stubcopy = STUBCPY $@
82       cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \
83                      then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \
84                      then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
85                            rm -f $@; /bin/false);                         \
86                      else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi        \
87                      else /bin/false; fi
88
89 #
90 # ARM discards the .data section because it disallows r/w data in the
91 # decompressor. So move our .data to .data.efistub, which is preserved
92 # explicitly by the decompressor linker script.
93 #
94 STUBCOPY_FLAGS-$(CONFIG_ARM)    += --rename-section .data=.data.efistub
95 STUBCOPY_RELOC-$(CONFIG_ARM)    := R_ARM_ABS