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Commit | Line | Data |
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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 | |
846221cf | 9 | cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ |
f4f75ad5 | 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)) | |
696204fa | 14 | cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ |
f4f75ad5 AB |
15 | -fno-builtin -fpic -mno-single-pic-base |
16 | ||
e8f3010f AB |
17 | cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt |
18 | ||
b523e185 | 19 | KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ |
3e2c044a | 20 | -D__NO_FORTIFY \ |
f4f75ad5 AB |
21 | $(call cc-option,-ffreestanding) \ |
22 | $(call cc-option,-fno-stack-protector) | |
23 | ||
24 | GCOV_PROFILE := n | |
0b24becc | 25 | KASAN_SANITIZE := n |
c6d30853 | 26 | UBSAN_SANITIZE := n |
c0dd6716 | 27 | OBJECT_FILES_NON_STANDARD := y |
f4f75ad5 | 28 | |
5c9a8750 DV |
29 | # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. |
30 | KCOV_INSTRUMENT := n | |
31 | ||
de8cb458 | 32 | lib-y := efi-stub-helper.o gop.o secureboot.o |
e8f3010f AB |
33 | |
34 | # include the stub's generic dependencies from lib/ when building for ARM/arm64 | |
35 | arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c | |
36 | ||
37 | $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE | |
38 | $(call if_changed_rule,cc_o_c) | |
39 | ||
a6a14469 | 40 | lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o random.o \ |
e8f3010f | 41 | $(patsubst %.c,lib-%.o,$(arm-deps)) |
f4f75ad5 | 42 | |
81a0bc39 | 43 | lib-$(CONFIG_ARM) += arm32-stub.o |
a6a14469 | 44 | lib-$(CONFIG_ARM64) += arm64-stub.o |
bf457786 AB |
45 | CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) |
46 | ||
ddeeefe2 AB |
47 | # |
48 | # arm64 puts the stub in the kernel proper, which will unnecessarily retain all | |
49 | # code indefinitely unless it is annotated as __init/__initdata/__initconst etc. | |
50 | # So let's apply the __init annotations at the section level, by prefixing | |
51 | # the section names directly. This will ensure that even all the inline string | |
52 | # literals are covered. | |
e8f3010f AB |
53 | # The fact that the stub and the kernel proper are essentially the same binary |
54 | # also means that we need to be extra careful to make sure that the stub does | |
55 | # not rely on any absolute symbol references, considering that the virtual | |
56 | # kernel mapping that the linker uses is not active yet when the stub is | |
57 | # executing. So build all C dependencies of the EFI stub into libstub, and do | |
58 | # a verification pass to see if any absolute relocations exist in any of the | |
59 | # object files. | |
ddeeefe2 | 60 | # |
e8f3010f AB |
61 | extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) |
62 | lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) | |
63 | ||
696204fa | 64 | STUBCOPY_RM-y := -R *ksymtab* -R *kcrctab* |
e8f3010f AB |
65 | STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ |
66 | --prefix-symbols=__efistub_ | |
67 | STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS | |
68 | ||
69 | $(obj)/%.stub.o: $(obj)/%.o FORCE | |
70 | $(call if_changed,stubcopy) | |
ddeeefe2 | 71 | |
696204fa AB |
72 | # |
73 | # Strip debug sections and some other sections that may legally contain | |
74 | # absolute relocations, so that we can inspect the remaining sections for | |
75 | # such relocations. If none are found, regenerate the output object, but | |
76 | # this time, use objcopy and leave all sections in place. | |
77 | # | |
e8f3010f | 78 | quiet_cmd_stubcopy = STUBCPY $@ |
696204fa AB |
79 | cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \ |
80 | then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \ | |
81 | then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ | |
82 | rm -f $@; /bin/false); \ | |
83 | else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi \ | |
84 | else /bin/false; fi | |
81a0bc39 RF |
85 | |
86 | # | |
87 | # ARM discards the .data section because it disallows r/w data in the | |
88 | # decompressor. So move our .data to .data.efistub, which is preserved | |
89 | # explicitly by the decompressor linker script. | |
90 | # | |
696204fa AB |
91 | STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub |
92 | STUBCOPY_RM-$(CONFIG_ARM) += -R ___ksymtab+sort -R ___kcrctab+sort | |
81a0bc39 | 93 | STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS |