11cd8a6483
If explicit relocation hints are used by the toolchain, -Wa,-mla-*
options will be useless for the C code. So only use them for the
!CONFIG_AS_HAS_EXPLICIT_RELOCS case.
Replace "la" with "la.pcrel" in head.S to keep the semantic consistent
with new and old toolchains for the low level startup code.
For per-CPU variables, the "address" of the symbol is actually an offset
from $r21. The value is near the loading address of main kernel image,
but far from the loading address of modules. So we use model("extreme")
attibute to tell the compiler that a PC-relative addressing with 32-bit
offset is not sufficient for local per-CPU variables.
The behavior with different assemblers and compilers are summarized in
the following table:
AS has CC has
explicit relocs explicit relocs * Behavior
==============================================================
No No Use la.* macros.
No change from Linux 6.0.
--------------------------------------------------------------
No Yes Disable explicit relocs.
No change from Linux 6.0.
--------------------------------------------------------------
Yes No Not supported.
--------------------------------------------------------------
Yes Yes Enable explicit relocs.
No -Wa,-mla* options used.
==============================================================
*: We assume CC must have model attribute if it has explicit relocs.
Both features are added in GCC 13 development cycle, so any GCC
release >= 13 should be OK. Using early GCC 13 development snapshots
may produce modules with unsupported relocations.
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=f09482a
Link: https://gcc.gnu.org/r13-1834
Link: https://gcc.gnu.org/r13-2199
Tested-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
129 lines
3.9 KiB
Makefile
129 lines
3.9 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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#
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# Author: Huacai Chen <chenhuacai@loongson.cn>
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# Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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boot := arch/loongarch/boot
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KBUILD_DEFCONFIG := loongson3_defconfig
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image-name-y := vmlinux
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image-name-$(CONFIG_EFI_ZBOOT) := vmlinuz
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ifndef CONFIG_EFI_STUB
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KBUILD_IMAGE := $(boot)/vmlinux.elf
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else
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KBUILD_IMAGE := $(boot)/$(image-name-y).efi
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endif
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#
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# Select the object file format to substitute into the linker script.
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#
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64bit-tool-archpref = loongarch64
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32bit-bfd = elf32-loongarch
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64bit-bfd = elf64-loongarch
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32bit-emul = elf32loongarch
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64bit-emul = elf64loongarch
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ifdef CONFIG_64BIT
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tool-archpref = $(64bit-tool-archpref)
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UTS_MACHINE := loongarch64
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endif
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ifneq ($(SUBARCH),$(ARCH))
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ifeq ($(CROSS_COMPILE),)
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CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux- $(tool-archpref)-linux-gnu- $(tool-archpref)-unknown-linux-gnu-)
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endif
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endif
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ifdef CONFIG_64BIT
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ld-emul = $(64bit-emul)
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cflags-y += -mabi=lp64s
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endif
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cflags-y += -G0 -pipe -msoft-float
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LDFLAGS_vmlinux += -G0 -static -n -nostdlib
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# When the assembler supports explicit relocation hint, we must use it.
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# GCC may have -mexplicit-relocs off by default if it was built with an old
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# assembler, so we force it via an option.
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#
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# When the assembler does not supports explicit relocation hint, we can't use
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# it. Disable it if the compiler supports it.
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#
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# If you've seen "unknown reloc hint" message building the kernel and you are
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# now wondering why "-mexplicit-relocs" is not wrapped with cc-option: the
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# combination of a "new" assembler and "old" compiler is not supported. Either
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# upgrade the compiler or downgrade the assembler.
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ifdef CONFIG_AS_HAS_EXPLICIT_RELOCS
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cflags-y += -mexplicit-relocs
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KBUILD_CFLAGS_KERNEL += -mdirect-extern-access
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else
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cflags-y += $(call cc-option,-mno-explicit-relocs)
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KBUILD_AFLAGS_KERNEL += -Wa,-mla-global-with-pcrel
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KBUILD_CFLAGS_KERNEL += -Wa,-mla-global-with-pcrel
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KBUILD_AFLAGS_MODULE += -Wa,-mla-global-with-abs
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KBUILD_CFLAGS_MODULE += -fplt -Wa,-mla-global-with-abs,-mla-local-with-abs
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endif
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cflags-y += -ffreestanding
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cflags-y += $(call cc-option, -mno-check-zero-division)
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load-y = 0x9000000000200000
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bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y)
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drivers-$(CONFIG_PCI) += arch/loongarch/pci/
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KBUILD_AFLAGS += $(cflags-y)
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KBUILD_CFLAGS += $(cflags-y)
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KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y)
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# This is required to get dwarf unwinding tables into .debug_frame
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# instead of .eh_frame so we don't discard them.
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KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
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# Don't emit unaligned accesses.
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# Not all LoongArch cores support unaligned access, and as kernel we can't
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# rely on others to provide emulation for these accesses.
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KBUILD_CFLAGS += $(call cc-option,-mstrict-align)
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KBUILD_CFLAGS += -isystem $(shell $(CC) -print-file-name=include)
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KBUILD_LDFLAGS += -m $(ld-emul)
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ifdef CONFIG_LOONGARCH
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CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
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egrep -vw '__GNUC_(MINOR_|PATCHLEVEL_)?_' | \
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sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
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endif
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head-y := arch/loongarch/kernel/head.o
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libs-y += arch/loongarch/lib/
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libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
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ifeq ($(KBUILD_EXTMOD),)
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prepare: vdso_prepare
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vdso_prepare: prepare0
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$(Q)$(MAKE) $(build)=arch/loongarch/vdso include/generated/vdso-offsets.h
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endif
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PHONY += vdso_install
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vdso_install:
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$(Q)$(MAKE) $(build)=arch/loongarch/vdso $@
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all: $(notdir $(KBUILD_IMAGE))
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vmlinux.elf vmlinux.efi vmlinuz.efi: vmlinux
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$(Q)$(MAKE) $(build)=$(boot) $(bootvars-y) $(boot)/$@
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install:
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$(Q)install -D -m 755 $(KBUILD_IMAGE) $(INSTALL_PATH)/$(image-name-y)-$(KERNELRELEASE)
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$(Q)install -D -m 644 .config $(INSTALL_PATH)/config-$(KERNELRELEASE)
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$(Q)install -D -m 644 System.map $(INSTALL_PATH)/System.map-$(KERNELRELEASE)
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define archhelp
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echo ' install - install kernel into $(INSTALL_PATH)'
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echo
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endef
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