Examples are:
- 1) head objects
-
- Some objects must be placed at the head of vmlinux. They are
- directly linked to vmlinux without going through built-in.a
- A typical use-case is an object that contains the entry point.
-
- arch/$(SRCARCH)/Makefile should specify such objects as head-y.
-
- Discussion:
- Given that we can control the section order in the linker script,
- why do we need head-y?
-
- 2) vmlinux linker script
+ 1) vmlinux linker script
The linker script for vmlinux is located at
arch/$(SRCARCH)/kernel/vmlinux.lds
Example::
# arch/x86/kernel/Makefile
- extra-y := head_$(BITS).o
- extra-y += head$(BITS).o
- extra-y += ebda.o
- extra-y += platform-quirks.o
extra-y += vmlinux.lds
$(extra-y) should only contain targets needed for vmlinux.
__all: modules
endif
+targets :=
+
# Decide whether to build built-in, modular, or both.
# Normally, just do built-in.
export ARCH_DRIVERS := $(drivers-y) $(drivers-m)
# Externally visible symbols (used by link-vmlinux.sh)
-KBUILD_VMLINUX_OBJS := $(head-y) ./built-in.a
+KBUILD_VMLINUX_OBJS := ./built-in.a
ifdef CONFIG_MODULES
KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
endif
-export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
+export KBUILD_VMLINUX_LIBS
export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
# Recurse until adjust_autoksyms.sh is satisfied
$(autoksyms_h):
$(call cmd,autoksyms_h)
-vmlinux.o: autoksyms_recursive $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
+# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
+quiet_cmd_ar_vmlinux.a = AR $@
+ cmd_ar_vmlinux.a = \
+ rm -f $@; \
+ $(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
+ $(AR) mPiT $$($(AR) t $@ | head -n1) $@ $(head-y)
+
+targets += vmlinux.a
+vmlinux.a: $(KBUILD_VMLINUX_OBJS) autoksyms_recursive FORCE
+ $(call if_changed,ar_vmlinux.a)
+
+vmlinux.o: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
vmlinux: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) modpost FORCE
+$(call if_changed_dep,link-vmlinux)
-targets := vmlinux
+targets += vmlinux
# The actual objects are generated when descending,
# make sure no implicit rule kicks in
cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
- $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
+ $(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
$(call if_changed,gen_compile_commands)
# Makefile for the linux kernel.
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
asflags-y := $(KBUILD_CFLAGS)
ccflags-y := -Wno-sign-compare
-obj-y := entry.o traps.o process.o osf_sys.o irq.o \
+obj-y := head.o entry.o traps.o process.o osf_sys.o irq.o \
irq_alpha.o signal.o setup.o ptrace.o time.o \
systbls.o err_common.o io.o bugs.o
# Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
#
-obj-y := arcksyms.o setup.o irq.o reset.o ptrace.o process.o devtree.o
+obj-y := head.o arcksyms.o setup.o irq.o reset.o ptrace.o process.o devtree.o
obj-y += signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o
obj-$(CONFIG_ISA_ARCOMPACT) += entry-compact.o intc-compact.o
obj-$(CONFIG_ISA_ARCV2) += entry-arcv2.o intc-arcv2.o
obj-y += ctx_sw_asm.o
endif
-extra-y := vmlinux.lds head.o
+extra-y := vmlinux.lds
obj-$(CONFIG_EFI) += efi.o
obj-$(CONFIG_PARAVIRT) += paravirt.o
-head-y := head$(MMUEXT).o
+obj-y += head$(MMUEXT).o
obj-$(CONFIG_DEBUG_LL) += debug.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_ARM_PATCH_PHYS_VIRT) += phys2virt.o
obj-$(CONFIG_GENERIC_CPU_VULNERABILITIES) += spectre.o
-extra-y := $(head-y) vmlinux.lds
+extra-y := vmlinux.lds
$(obj)/vdso32-wrap.o: $(obj)/vdso32/vdso.so
obj-y += probes/
-head-y := head.o
-extra-y += $(head-y) vmlinux.lds
+obj-y += head.o
+extra-y += vmlinux.lds
ifeq ($(CONFIG_DEBUG_EFI),y)
AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
# SPDX-License-Identifier: GPL-2.0-only
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o vdso/
+obj-y += head.o entry.o atomic.o signal.o traps.o irq.o time.o vdso.o vdso/
obj-y += power.o syscall.o syscall_table.o setup.o io.o
obj-y += process.o cpu-probe.o ptrace.o stacktrace.o
obj-y += probes/
# SPDX-License-Identifier: GPL-2.0
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
+obj-y += head.o
obj-$(CONFIG_SMP) += smp.o
obj-y += setup.o irq_cpu.o traps.o syscalltab.o signal.o time.o
CFLAGS_REMOVE_ftrace.o = -pg
endif
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y := entry.o efi.o efi_stub.o gate-data.o fsys.o irq.o irq_ia64.o \
+obj-y := head.o entry.o efi.o efi_stub.o gate-data.o fsys.o irq.o irq_ia64.o \
irq_lsapic.o ivt.o pal.o patch.o process.o ptrace.o sal.o \
salinfo.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o \
unwind.o mca.o mca_asm.o topology.o dma-mapping.o iosapic.o acpi.o \
# Makefile for the Linux/LoongArch kernel.
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y += cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \
+obj-y += head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \
traps.o irq.o idle.o process.o dma.o mem.o io.o reset.o switch.o \
elf.o syscall.o signal.o time.o topology.o inst.o ptrace.o vdso.o
obj-$(CONFIG_UCSIMM) += ucsimm.o
obj-$(CONFIG_UCDIMM) += ucsimm.o
-extra-y := head.o
+obj-y += head.o
obj-$(CONFIG_PCI) += pci.o
obj-y += gpio.o
-extra-y := head.o
+obj-y += head.o
# Makefile for the linux kernel.
#
-extra-$(CONFIG_AMIGA) := head.o
-extra-$(CONFIG_ATARI) := head.o
-extra-$(CONFIG_MAC) := head.o
-extra-$(CONFIG_APOLLO) := head.o
-extra-$(CONFIG_VME) := head.o
-extra-$(CONFIG_HP300) := head.o
-extra-$(CONFIG_Q40) := head.o
-extra-$(CONFIG_SUN3X) := head.o
-extra-$(CONFIG_VIRT) := head.o
-extra-$(CONFIG_SUN3) := sun3-head.o
extra-y += vmlinux.lds
-obj-y := entry.o irq.o module.o process.o ptrace.o
+obj-$(CONFIG_AMIGA) := head.o
+obj-$(CONFIG_ATARI) := head.o
+obj-$(CONFIG_MAC) := head.o
+obj-$(CONFIG_APOLLO) := head.o
+obj-$(CONFIG_VME) := head.o
+obj-$(CONFIG_HP300) := head.o
+obj-$(CONFIG_Q40) := head.o
+obj-$(CONFIG_SUN3X) := head.o
+obj-$(CONFIG_VIRT) := head.o
+obj-$(CONFIG_SUN3) := sun3-head.o
+
+obj-y += entry.o irq.o module.o process.o ptrace.o
obj-y += setup.o signal.o sys_m68k.o syscalltable.o time.o traps.o
obj-$(CONFIG_MMU_MOTOROLA) += ints.o vectors.o
CFLAGS_REMOVE_process.o = -pg
endif
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y += dma.o exceptions.o \
+obj-y += head.o dma.o exceptions.o \
hw_exception_handler.o irq.o \
process.o prom.o ptrace.o \
reset.o setup.o signal.o sys_microblaze.o timer.o traps.o unwind.o
# Makefile for the Linux/MIPS kernel.
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y += branch.o cmpxchg.o elf.o entry.o genex.o idle.o irq.o \
+obj-y += head.o branch.o cmpxchg.o elf.o entry.o genex.o idle.o irq.o \
process.o prom.o ptrace.o reset.o setup.o signal.o \
syscall.o time.o topology.o traps.o unaligned.o watch.o \
vdso.o cacheinfo.o
# Makefile for the nios2 linux kernel.
#
-extra-y += head.o
extra-y += vmlinux.lds
+obj-y += head.o
obj-y += cpuinfo.o
obj-y += entry.o
obj-y += insnemu.o
# Makefile for the linux kernel.
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y := setup.o or32_ksyms.o process.o dma.o \
+obj-y := head.o setup.o or32_ksyms.o process.o dma.o \
traps.o time.o irq.o entry.o ptrace.o signal.o \
sys_call_table.o unwinder.o
# Makefile for arch/parisc/kernel
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y := cache.o pacache.o setup.o pdt.o traps.o time.o irq.o \
+obj-y := head.o cache.o pacache.o setup.o pdt.o traps.o time.o irq.o \
pa7300lc.o syscall.o entry.o sys_parisc.o firmware.o \
ptrace.o hardware.o inventory.o drivers.o alternative.o \
signal.o hpmc.o real2.o parisc_ksyms.o unaligned.o \
obj-$(CONFIG_PPC_DOORBELL) += dbell.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
-extra-$(CONFIG_PPC64) := head_64.o
-extra-$(CONFIG_PPC_BOOK3S_32) := head_book3s_32.o
-extra-$(CONFIG_40x) := head_40x.o
-extra-$(CONFIG_44x) := head_44x.o
-extra-$(CONFIG_FSL_BOOKE) := head_fsl_booke.o
-extra-$(CONFIG_PPC_8xx) := head_8xx.o
+obj-$(CONFIG_PPC64) += head_64.o
+obj-$(CONFIG_PPC_BOOK3S_32) += head_book3s_32.o
+obj-$(CONFIG_40x) += head_40x.o
+obj-$(CONFIG_44x) += head_44x.o
+obj-$(CONFIG_FSL_BOOKE) += head_fsl_booke.o
+obj-$(CONFIG_PPC_8xx) += head_8xx.o
extra-y += vmlinux.lds
obj-$(CONFIG_RELOCATABLE) += reloc_$(BITS).o
CFLAGS_setup_64.o += -fno-stack-protector
CFLAGS_paca.o += -fno-stack-protector
-extra-$(CONFIG_PPC_FPU) += fpu.o
-extra-$(CONFIG_ALTIVEC) += vector.o
-extra-$(CONFIG_PPC64) += entry_64.o
-extra-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init.o
+obj-$(CONFIG_PPC_FPU) += fpu.o
+obj-$(CONFIG_ALTIVEC) += vector.o
+obj-$(CONFIG_PPC64) += entry_64.o
+obj-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init.o
extra-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init_check
endif
endif
-extra-y += head.o
extra-y += vmlinux.lds
+obj-y += head.o
obj-y += soc.o
obj-$(CONFIG_RISCV_ALTERNATIVE) += alternative.o
obj-y += cpu.o
CFLAGS_dumpstack.o += -fno-optimize-sibling-calls
CFLAGS_unwind_bc.o += -fno-optimize-sibling-calls
-obj-y := traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
+obj-y := head64.o traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
obj-y += processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o cpufeature.o
obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o
obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
obj-y += smp.o text_amode31.o stacktrace.o
-extra-y += head64.o vmlinux.lds
+extra-y += vmlinux.lds
obj-$(CONFIG_SYSFS) += nospec-sysfs.o
CFLAGS_REMOVE_nospec-branch.o += $(CC_FLAGS_EXPOLINE)
# Makefile for the Linux/SuperH kernel.
#
-extra-y := head_32.o vmlinux.lds
+extra-y := vmlinux.lds
ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities
CFLAGS_REMOVE_return_address.o = -pg
-obj-y := debugtraps.o dumpstack.o \
+obj-y := head_32.o debugtraps.o dumpstack.o \
idle.o io.o irq.o irq_32.o kdebugfs.o \
machvec.o nmi_debug.o process.o \
process_32.o ptrace.o ptrace_32.o \
asflags-y := -ansi
ccflags-y := -Werror
-extra-y := head_$(BITS).o
-
# Undefine sparc when processing vmlinux.lds - it is used
# And teach CPP we are doing $(BITS) builds (for this case)
CPPFLAGS_vmlinux.lds := -Usparc -m$(BITS)
CFLAGS_REMOVE_pcr.o := -pg
endif
+obj-y := head_$(BITS).o
obj-$(CONFIG_SPARC64) += urtt_fill.o
obj-$(CONFIG_SPARC32) += entry.o wof.o wuf.o
obj-$(CONFIG_SPARC32) += etrap_32.o
# Makefile for the linux kernel.
#
-extra-y := head_$(BITS).o
-extra-y += head$(BITS).o
-extra-y += ebda.o
-extra-y += platform-quirks.o
extra-y += vmlinux.lds
CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE)
CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
-obj-y := process_$(BITS).o signal.o
+obj-y += head_$(BITS).o
+obj-y += head$(BITS).o
+obj-y += ebda.o
+obj-y += platform-quirks.o
+obj-y += process_$(BITS).o signal.o
obj-$(CONFIG_COMPAT) += signal_compat.o
obj-y += traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
obj-y += time.o ioport.o dumpstack.o nmi.o
# Makefile for the Linux/Xtensa kernel.
#
-extra-y := head.o vmlinux.lds
+extra-y := vmlinux.lds
-obj-y := align.o coprocessor.o entry.o irq.o platform.o process.o \
+obj-y := head.o align.o coprocessor.o entry.o irq.o platform.o process.o \
ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
vectors.o
for f in $(real-prereqs); do \
case $${f} in \
*libgcc.a) ;; \
- *.a) $(AR) t $${f} ;; \
- *) echo $${f} ;; \
+ *) $(AR) t $${f} ;; \
esac \
done > $@
targets += .vmlinux.objs
-.vmlinux.objs: $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
+.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed,vmlinux_objs)
vmlinux.o-if-present := $(wildcard vmlinux.o)
$(PERL) $(real-prereqs) > $@
.tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
- $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
+ vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed,gen_initcalls_lds)
targets := .tmp_initcalls.lds
cmd_ld_vmlinux.o = \
$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
$(addprefix -T , $(initcalls-lds)) \
- --whole-archive $(KBUILD_VMLINUX_OBJS) --no-whole-archive \
+ --whole-archive vmlinux.a --no-whole-archive \
--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
$(cmd_objtool)
$(call cmd,gen_objtooldep)
endef
-vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
+vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed_rule,ld_vmlinux.o)
targets += vmlinux.o
return os.path.join(dir, '.' + base + '.cmd')
-def cmdfiles_for_o(obj):
- """Generate the iterator of .cmd files associated with the object
-
- Yield the .cmd file used to build the given object
-
- Args:
- obj: The object path
-
- Yields:
- The path to .cmd file
- """
- yield to_cmdfile(obj)
-
-
def cmdfiles_for_a(archive, ar):
"""Generate the iterator of .cmd files associated with the archive.
for path in paths:
# If 'path' is a directory, handle all .cmd files under it.
# Otherwise, handle .cmd files associated with the file.
- # Most of built-in objects are linked via archives (built-in.a or lib.a)
- # but some objects are linked to vmlinux directly.
+ # built-in objects are linked via vmlinux.a
# Modules are listed in modules.order.
if os.path.isdir(path):
cmdfiles = cmdfiles_in_dir(path)
- elif path.endswith('.o'):
- cmdfiles = cmdfiles_for_o(path)
elif path.endswith('.a'):
cmdfiles = cmdfiles_for_a(path, ar)
elif path.endswith('modules.order'):
#
# link vmlinux
#
-# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_OBJS) and
-# $(KBUILD_VMLINUX_LIBS). Most are built-in.a files from top-level directories
-# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
+# vmlinux is linked from the objects in vmlinux.a and $(KBUILD_VMLINUX_LIBS).
+# vmlinux.a contains objects that are linked unconditionally.
# $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
# (not within --whole-archive), and do not require symbol indexes added.
#
# vmlinux
# ^
# |
-# +--< $(KBUILD_VMLINUX_OBJS)
-# | +--< init/built-in.a drivers/built-in.a mm/built-in.a + more
+# +--< vmlinux.a
# |
# +--< $(KBUILD_VMLINUX_LIBS)
# | +--< lib/lib.a + more
objs=vmlinux.o
libs=
else
- objs="${KBUILD_VMLINUX_OBJS}"
+ objs=vmlinux.a
libs="${KBUILD_VMLINUX_LIBS}"
fi
projects / platform / kernel / linux-rpi.git / commitdiff