Makefile (420b6d00ca94ce5b6578b1bc12e767ac7a0251ac) | Makefile (26a92425f9a301fdeb5482e7891915ce43cc0556) |
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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# 8cflags-$(CONFIG_X86_32) := -march=i386 --- 47 unchanged lines hidden (view full) --- 56 57lib-$(CONFIG_ARM) += arm32-stub.o 58lib-$(CONFIG_ARM64) += arm64-stub.o 59lib-$(CONFIG_X86) += x86-stub.o 60CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) 61CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) 62 63# | 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# 8cflags-$(CONFIG_X86_32) := -march=i386 --- 47 unchanged lines hidden (view full) --- 56 57lib-$(CONFIG_ARM) += arm32-stub.o 58lib-$(CONFIG_ARM64) += arm64-stub.o 59lib-$(CONFIG_X86) += x86-stub.o 60CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) 61CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) 62 63# |
64# For x86, bootloaders like systemd-boot or grub-efi do not zero-initialize the 65# .bss section, so the .bss section of the EFI stub needs to be included in the 66# .data section of the compressed kernel to ensure initialization. Rename the 67# .bss section here so it's easy to pick out in the linker script. 68# 69STUBCOPY_FLAGS-$(CONFIG_X86) += --rename-section .bss=.bss.efistub,load,alloc 70STUBCOPY_RELOC-$(CONFIG_X86_32) := R_386_32 71STUBCOPY_RELOC-$(CONFIG_X86_64) := R_X86_64_64 72 73# 74# ARM discards the .data section because it disallows r/w data in the 75# decompressor. So move our .data to .data.efistub and .bss to .bss.efistub, 76# which are preserved explicitly by the decompressor linker script. 77# 78STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub \ 79 --rename-section .bss=.bss.efistub,load,alloc 80STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS 81 82# |
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64# arm64 puts the stub in the kernel proper, which will unnecessarily retain all 65# code indefinitely unless it is annotated as __init/__initdata/__initconst etc. 66# So let's apply the __init annotations at the section level, by prefixing 67# the section names directly. This will ensure that even all the inline string 68# literals are covered. 69# The fact that the stub and the kernel proper are essentially the same binary 70# also means that we need to be extra careful to make sure that the stub does 71# not rely on any absolute symbol references, considering that the virtual 72# kernel mapping that the linker uses is not active yet when the stub is 73# executing. So build all C dependencies of the EFI stub into libstub, and do 74# a verification pass to see if any absolute relocations exist in any of the 75# object files. 76# | 83# arm64 puts the stub in the kernel proper, which will unnecessarily retain all 84# code indefinitely unless it is annotated as __init/__initdata/__initconst etc. 85# So let's apply the __init annotations at the section level, by prefixing 86# the section names directly. This will ensure that even all the inline string 87# literals are covered. 88# The fact that the stub and the kernel proper are essentially the same binary 89# also means that we need to be extra careful to make sure that the stub does 90# not rely on any absolute symbol references, considering that the virtual 91# kernel mapping that the linker uses is not active yet when the stub is 92# executing. So build all C dependencies of the EFI stub into libstub, and do 93# a verification pass to see if any absolute relocations exist in any of the 94# object files. 95# |
77extra-$(CONFIG_EFI_GENERIC_STUB) := $(lib-y) 78lib-$(CONFIG_EFI_GENERIC_STUB) := $(patsubst %.o,%.stub.o,$(lib-y)) | 96extra-y := $(lib-y) 97lib-y := $(patsubst %.o,%.stub.o,$(lib-y)) |
79 80STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ 81 --prefix-symbols=__efistub_ 82STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS 83 84$(obj)/%.stub.o: $(obj)/%.o FORCE 85 $(call if_changed,stubcopy) 86 --- 6 unchanged lines hidden (view full) --- 93quiet_cmd_stubcopy = STUBCPY $@ 94 cmd_stubcopy = \ 95 $(STRIP) --strip-debug -o $@ $<; \ 96 if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); then \ 97 echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \ 98 /bin/false; \ 99 fi; \ 100 $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@ | 98 99STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ 100 --prefix-symbols=__efistub_ 101STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS 102 103$(obj)/%.stub.o: $(obj)/%.o FORCE 104 $(call if_changed,stubcopy) 105 --- 6 unchanged lines hidden (view full) --- 112quiet_cmd_stubcopy = STUBCPY $@ 113 cmd_stubcopy = \ 114 $(STRIP) --strip-debug -o $@ $<; \ 115 if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); then \ 116 echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \ 117 /bin/false; \ 118 fi; \ 119 $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@ |
101 102# 103# ARM discards the .data section because it disallows r/w data in the 104# decompressor. So move our .data to .data.efistub and .bss to .bss.efistub, 105# which are preserved explicitly by the decompressor linker script. 106# 107STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub \ 108 --rename-section .bss=.bss.efistub,load,alloc 109STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS | |