arch/arm/vdso/Makefile

Source file repositories/reference/linux-study-clean/arch/arm/vdso/Makefile

File Facts

System
Linux kernel
Corpus path
arch/arm/vdso/Makefile
Extension
[no extension]
Size
1638 bytes
Lines
57
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: build/configuration rule
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

# SPDX-License-Identifier: GPL-2.0

# Include the generic Makefile to check the built vdso.
include $(srctree)/lib/vdso/Makefile.include

hostprogs := vdsomunge

obj-vdso := vgettimeofday.o note.o

# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))

ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector
ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO32

ldflags-$(CONFIG_CPU_ENDIAN_BE8) := --be8
ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
	    -z max-page-size=4096 -shared $(ldflags-y) \
	    --hash-style=sysv --build-id=sha1 \
	    -T

obj-$(CONFIG_VDSO) += vdso.o
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)

CFLAGS_REMOVE_vdso.o = -pg

# Force -O2 to avoid libgcc dependencies
CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(RANDSTRUCT_CFLAGS) $(KSTACK_ERASE_CFLAGS) $(GCC_PLUGINS_CFLAGS)
ifeq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o = -O2
else
CFLAGS_vgettimeofday.o = -O2 -include $(c-gettimeofday-y)
endif

# Force dependency
$(obj)/vdso.o : $(obj)/vdso.so

# Link rule for the .so file
$(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
	$(call if_changed,vdsold_and_vdso_check)

$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
	$(call if_changed,vdsomunge)

# Strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
	$(call if_changed,objcopy)

# Actual build commands
quiet_cmd_vdsold_and_vdso_check = LD      $@
      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)

quiet_cmd_vdsomunge = MUNGE   $@
      cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@

Annotation

Implementation Notes