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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 | |
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 |
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 | |
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 |