427abfa28a
Being named "Crazed Snow-Weasel" instills a lot of confidence in this release, so I'm sure this will be one of the better ones.
44 KiB
VERSION = 2 PATCHLEVEL = 6 SUBLEVEL = 17 EXTRAVERSION = NAME=Crazed Snow-Weasel
DOCUMENTATION
To see a list of typical targets execute "make help"
More info can be located in ./README
Comments in this file are targeted only to the developer, do not
expect to learn how to build the kernel reading this file.
Do not print "Entering directory ..."
MAKEFLAGS += --no-print-directory
We are using a recursive build, so we need to do a little thinking
to get the ordering right.
Most importantly: sub-Makefiles should only ever modify files in
their own directory. If in some directory we have a dependency on
a file in another dir (which doesn't happen often, but it's often
unavoidable when linking the built-in.o targets which finally
turn into vmlinux), we will call a sub make in that other dir, and
after that we are sure that everything which is in that other dir
is now up to date.
The only cases where we need to modify files which have global
effects are thus separated out and done before the recursive
descending is started. They are now explicitly listed as the
prepare rule.
To put more focus on warnings, be less verbose as default
Use 'make V=1' to see the full commands
ifdef V ifeq ("$(origin V)", "command line") KBUILD_VERBOSE = $(V) endif endif ifndef KBUILD_VERBOSE KBUILD_VERBOSE = 0 endif
Call sparse as part of compilation of C files
Use 'make C=1' to enable sparse checking
ifdef C ifeq ("$(origin C)", "command line") KBUILD_CHECKSRC = $(C) endif endif ifndef KBUILD_CHECKSRC KBUILD_CHECKSRC = 0 endif
Use make M=dir to specify directory of external module to build
Old syntax make ... SUBDIRS=$PWD is still supported
Setting the environment variable KBUILD_EXTMOD take precedence
ifdef SUBDIRS KBUILD_EXTMOD ?= $(SUBDIRS) endif ifdef M ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif endif
kbuild supports saving output files in a separate directory.
To locate output files in a separate directory two syntaxes are supported.
In both cases the working directory must be the root of the kernel src.
1) O=
Use "make O=dir/to/store/output/files/"
2) Set KBUILD_OUTPUT
Set the environment variable KBUILD_OUTPUT to point to the directory
where the output files shall be placed.
export KBUILD_OUTPUT=dir/to/store/output/files/
make
The O= assignment takes precedence over the KBUILD_OUTPUT environment
variable.
KBUILD_SRC is set on invocation of make in OBJ directory
KBUILD_SRC is not intended to be used by the regular user (for now)
ifeq ($(KBUILD_SRC),)
OK, Make called in directory where kernel src resides
Do we want to locate output files in a separate directory?
ifdef O ifeq ("$(origin O)", "command line") KBUILD_OUTPUT := $(O) endif endif
That's our default target when none is given on the command line
PHONY := _all _all:
ifneq ($(KBUILD_OUTPUT),)
Invoke a second make in the output directory, passing relevant variables
check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
$(if $(KBUILD_OUTPUT),,
$(error output directory "$(saved-output)" does not exist))
PHONY += $(MAKECMDGOALS)
$(filter-out _all,$(MAKECMDGOALS)) _all:
$(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT)
KBUILD_SRC=$(CURDIR)
KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile $@
Leave processing to above invocation of make
skip-makefile := 1 endif # ifneq ($(KBUILD_OUTPUT),) endif # ifeq ($(KBUILD_SRC),)
We process the rest of the Makefile if this is the final invocation of make
ifeq ($(skip-makefile),)
If building an external module we do not care about the all: rule
but instead _all depend on modules
PHONY += all ifeq ($(KBUILD_EXTMOD),) _all: all else _all: modules endif
srctree := $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR)) TOPDIR := $(srctree)
FIXME - TOPDIR is obsolete, use srctree/objtree
objtree := $(CURDIR) src := $(srctree) obj := $(objtree)
VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
export srctree objtree VPATH TOPDIR
SUBARCH tells the usermode build what the underlying arch is. That is set
first, and if a usermode build is happening, the "ARCH=um" on the command
line overrides the setting of ARCH below. If a native build is happening,
then ARCH is assigned, getting whatever value it gets normally, and
SUBARCH is subsequently ignored.
SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/
-e s/arm./arm/ -e s/sa110/arm/
-e s/s390x/s390/ -e s/parisc64/parisc/
-e s/ppc./powerpc/ -e s/mips.*/mips/ )
Cross compiling and selecting different set of gcc/bin-utils
---------------------------------------------------------------------------
When performing cross compilation for other architectures ARCH shall be set
to the target architecture. (See arch/* for the possibilities).
ARCH can be set during invocation of make:
make ARCH=ia64
Another way is to have ARCH set in the environment.
The default ARCH is the host where make is executed.
CROSS_COMPILE specify the prefix used for all executables used
during compilation. Only gcc and related bin-utils executables
are prefixed with $(CROSS_COMPILE).
CROSS_COMPILE can be set on the command line
make CROSS_COMPILE=ia64-linux-
Alternatively CROSS_COMPILE can be set in the environment.
Default value for CROSS_COMPILE is not to prefix executables
Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
ARCH ?= $(SUBARCH) CROSS_COMPILE ?=
Architecture as present in compile.h
UTS_MACHINE := $(ARCH)
SHELL used by kbuild
CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH;
else if [ -x /bin/bash ]; then echo /bin/bash;
else echo sh; fi ; fi)
HOSTCC = gcc HOSTCXX = g++ HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer HOSTCXXFLAGS = -O2
Decide whether to build built-in, modular, or both.
Normally, just do built-in.
KBUILD_MODULES := KBUILD_BUILTIN := 1
If we have only "make modules", don't compile built-in objects.
When we're building modules with modversions, we need to consider
the built-in objects during the descend as well, in order to
make sure the checksums are uptodate before we record them.
ifeq ($(MAKECMDGOALS),modules) KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) endif
If we have "make modules", compile modules
in addition to whatever we do anyway.
Just "make" or "make all" shall build modules as well
ifneq ($(filter all _all modules,$(MAKECMDGOALS)),) KBUILD_MODULES := 1 endif
ifeq ($(MAKECMDGOALS),) KBUILD_MODULES := 1 endif
export KBUILD_MODULES KBUILD_BUILTIN export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
Beautify output
---------------------------------------------------------------------------
Normally, we echo the whole command before executing it. By making
that echo $($(quiet)$(cmd)), we now have the possibility to set
$(quiet) to choose other forms of output instead, e.g.
quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
If $(quiet) is empty, the whole command will be printed.
If it is set to "quiet_", only the short version will be printed.
If it is set to "silent_", nothing wil be printed at all, since
the variable $(silent_cmd_cc_o_c) doesn't exist.
A simple variant is to prefix commands with $(Q) - that's useful
for commands that shall be hidden in non-verbose mode.
$(Q)ln $@ :<
If KBUILD_VERBOSE equals 0 then the above command will be hidden.
If KBUILD_VERBOSE equals 1 then the above command is displayed.
ifeq ($(KBUILD_VERBOSE),1) quiet = Q = else quiet=quiet_ Q = @ endif
If the user is running make -s (silent mode), suppress echoing of
commands
ifneq ($(findstring s,$(MAKEFLAGS)),) quiet=silent_ endif
export quiet Q KBUILD_VERBOSE
Look for make include files relative to root of kernel src
MAKEFLAGS += --include-dir=$(srctree)
We need some generic definitions
include $(srctree)/scripts/Kbuild.include
For maximum performance (+ possibly random breakage, uncomment
the following)
#MAKEFLAGS += -rR
Make variables (CC, etc...)
AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld CC = $(CROSS_COMPILE)gcc CPP = $(CC) -E AR = $(CROSS_COMPILE)ar NM = $(CROSS_COMPILE)nm STRIP = $(CROSS_COMPILE)strip OBJCOPY = $(CROSS_COMPILE)objcopy OBJDUMP = $(CROSS_COMPILE)objdump AWK = awk GENKSYMS = scripts/genksyms/genksyms DEPMOD = /sbin/depmod KALLSYMS = scripts/kallsyms PERL = perl CHECK = sparse
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise $(CF) MODFLAGS = -DMODULE CFLAGS_MODULE = $(MODFLAGS) AFLAGS_MODULE = $(MODFLAGS) LDFLAGS_MODULE = -r CFLAGS_KERNEL = AFLAGS_KERNEL =
Use LINUXINCLUDE when you must reference the include/ directory.
Needed to be compatible with the O= option
LINUXINCLUDE := -Iinclude
$(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include)
-include include/linux/autoconf.h
CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
-fno-strict-aliasing -fno-common
AFLAGS := -D__ASSEMBLY__
Read KERNELRELEASE from .kernelrelease (if it exists)
KERNELRELEASE = $(shell cat .kernelrelease 2> /dev/null) KERNELVERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
ARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
export CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE export AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
When compiling out-of-tree modules, put MODVERDIR in the module
tree rather than in the kernel tree. The kernel tree might
even be read-only.
export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
Files to ignore in find ... statements
RCS_FIND_IGNORE := -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS -o -name .pc -o -name .hg -o -name .git -prune -o
export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn --exclude CVS --exclude .pc --exclude .hg --exclude .git
===========================================================================
Rules shared between *config targets and build targets
Basic helpers built in scripts/
PHONY += scripts_basic scripts_basic: $(Q)$(MAKE) $(build)=scripts/basic
To avoid any implicit rule to kick in, define an empty command.
scripts/basic/%: scripts_basic ;
PHONY += outputmakefile
outputmakefile generates a Makefile in the output directory, if using a
separate output directory. This allows convenient use of make in the
output directory.
outputmakefile:
ifneq ($(KBUILD_SRC),)
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile
$(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
endif
To make sure we do not include .config for any of the *config targets
catch them early, and hand them over to scripts/kconfig/Makefile
It is allowed to specify more targets when calling make, including
mixing *config targets and build targets.
For example 'make oldconfig all'.
Detect when mixed targets is specified, and make a second invocation
of make so .config is not included in this case either (for *config).
no-dot-config-targets := clean mrproper distclean
cscope TAGS tags help %docs check%
config-targets := 0 mixed-targets := 0 dot-config := 1
ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) dot-config := 0 endif endif
ifeq ($(KBUILD_EXTMOD),) ifneq ($(filter config %config,$(MAKECMDGOALS)),) config-targets := 1 ifneq ($(filter-out config %config,$(MAKECMDGOALS)),) mixed-targets := 1 endif endif endif
ifeq ($(mixed-targets),1)
===========================================================================
We're called with mixed targets (*config and build targets).
Handle them one by one.
%:: FORCE $(Q)$(MAKE) -C $(srctree) KBUILD_SRC= $@
else ifeq ($(config-targets),1)
===========================================================================
*config targets only - make sure prerequisites are updated, and descend
in scripts/kconfig to make the *config target
Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
KBUILD_DEFCONFIG may point out an alternative default configuration
used for 'make defconfig'
include $(srctree)/arch/$(ARCH)/Makefile export KBUILD_DEFCONFIG
config %config: scripts_basic outputmakefile FORCE $(Q)mkdir -p include/linux $(Q)$(MAKE) $(build)=scripts/kconfig $@ $(Q)$(MAKE) -C $(srctree) KBUILD_SRC= .kernelrelease
else
===========================================================================
Build targets only - this includes vmlinux, arch specific targets, clean
targets and others. In general all targets except *config targets.
ifeq ($(KBUILD_EXTMOD),)
Additional helpers built in scripts/
Carefully list dependencies so we do not try to build scripts twice
in parrallel
PHONY += scripts scripts: scripts_basic include/config/MARKER $(Q)$(MAKE) $(build)=$(@)
scripts_basic: include/linux/autoconf.h
Objects we will link into vmlinux / subdirs we need to visit
init-y := init/ drivers-y := drivers/ sound/ net-y := net/ libs-y := lib/ core-y := usr/ endif # KBUILD_EXTMOD
ifeq ($(dot-config),1)
In this section, we need .config
Read in dependencies to all Kconfig* files, make sure to run
oldconfig if changes are detected.
-include .kconfig.d
include .config
If .config needs to be updated, it will be done via the dependency
that autoconf has on .config.
To avoid any implicit rule to kick in, define an empty command
.config .kconfig.d: ;
If .config is newer than include/linux/autoconf.h, someone tinkered
with it and forgot to run make oldconfig.
If kconfig.d is missing then we are probarly in a cleaned tree so
we execute the config step to be sure to catch updated Kconfig files
include/linux/autoconf.h: .kconfig.d .config $(Q)mkdir -p include/linux $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig else
Dummy target needed, because used as prerequisite
include/linux/autoconf.h: ; endif
The all: target is the default when no target is given on the
command line.
This allow a user to issue only 'make' to build a kernel including modules
Defaults vmlinux but it is usually overriden in the arch makefile
all: vmlinux
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE CFLAGS += -Os else CFLAGS += -O2 endif
ifdef CONFIG_FRAME_POINTER CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,) else CFLAGS += -fomit-frame-pointer endif
ifdef CONFIG_UNWIND_INFO CFLAGS += -fasynchronous-unwind-tables endif
ifdef CONFIG_DEBUG_INFO CFLAGS += -g endif
include $(srctree)/arch/$(ARCH)/Makefile
arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) CHECKFLAGS += $(NOSTDINC_FLAGS)
warn about C99 declaration after statement
CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
disable pointer signedness warnings in gcc 4.0
CFLAGS += $(call cc-option,-Wno-pointer-sign,)
Default kernel image to build when no specific target is given.
KBUILD_IMAGE may be overruled on the commandline or
set in the environment
Also any assignments in arch/$(ARCH)/Makefile take precedence over
this default value
export KBUILD_IMAGE ?= vmlinux
INSTALL_PATH specifies where to place the updated kernel and system map
images. Default is /boot, but you can set it to other values
export INSTALL_PATH ?= /boot
INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
relocations required by build roots. This is not defined in the
makefile but the arguement can be passed to make if needed.
MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB
ifeq ($(KBUILD_EXTMOD),) core-y += kernel/ mm/ fs/ ipc/ security/ crypto/ block/
vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m)
$(core-y) $(core-m) $(drivers-y) $(drivers-m)
$(net-y) $(net-m) $(libs-y) $(libs-m)))
vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/,
$(init-n) $(init-)
$(core-n) $(core-) $(drivers-n) $(drivers-)
$(net-n) $(net-) $(libs-n) $(libs-))))
init-y := $(patsubst %/, %/built-in.o, $(init-y)) core-y := $(patsubst %/, %/built-in.o, $(core-y)) drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y)) net-y := $(patsubst %/, %/built-in.o, $(net-y)) libs-y1 := $(patsubst %/, %/lib.a, $(libs-y)) libs-y2 := $(patsubst %/, %/built-in.o, $(libs-y)) libs-y := $(libs-y1) $(libs-y2)
Build vmlinux
---------------------------------------------------------------------------
vmlinux is build from the objects selected by $(vmlinux-init) and
$(vmlinux-main). Most are built-in.o files from top-level directories
in the kernel tree, others are specified in arch/$(ARCH)Makefile.
Ordering when linking is important, and $(vmlinux-init) must be first.
vmlinux
^
|
+-< $(vmlinux-init)
| +--< init/version.o + more
|
+--< $(vmlinux-main)
| +--< driver/built-in.o mm/built-in.o + more
|
+-< kallsyms.o (see description in CONFIG_KALLSYMS section)
vmlinux version (uname -v) cannot be updated during normal
descending-into-subdirs phase since we do not yet know if we need to
update vmlinux.
Therefore this step is delayed until just before final link of vmlinux -
except in the kallsyms case where it is done just before adding the
symbols to the kernel.
System.map is generated to document addresses of all kernel symbols
vmlinux-init := $(head-y) $(init-y) vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y) vmlinux-all := $(vmlinux-init) $(vmlinux-main) vmlinux-lds := arch/$(ARCH)/kernel/vmlinux.lds
Rule to link vmlinux - also used during CONFIG_KALLSYMS
May be overridden by arch/$(ARCH)/Makefile
quiet_cmd_vmlinux__ ?= LD $@
cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@
-T $(vmlinux-lds) $(vmlinux-init)
--start-group $(vmlinux-main) --end-group
$(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) FORCE ,$^)
Generate new vmlinux version
quiet_cmd_vmlinux_version = GEN .version
cmd_vmlinux_version = set -e;
if [ ! -r .version ]; then
rm -f .version;
echo 1 >.version;
else
mv .version .old_version;
expr 0$$(cat .old_version) + 1 >.version;
fi;
$(MAKE) $(build)=init
Generate System.map
quiet_cmd_sysmap = SYSMAP cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap
Link of vmlinux
If CONFIG_KALLSYMS is set .version is already updated
Generate System.map and verify that the content is consistent
Use + in front of the vmlinux_version rule to silent warning with make -j2
First command is ':' to allow us to use + in front of the rule
define rule_vmlinux__ : $(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))
$(call cmd,vmlinux__)
$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
$(Q)$(if $($(quiet)cmd_sysmap), \
echo ' $($(quiet)cmd_sysmap) System.map' &&) \
$(cmd_sysmap) $@ System.map; \
if [ $$? -ne 0 ]; then \
rm -f $@; \
/bin/false; \
fi;
$(verify_kallsyms)
endef
ifdef CONFIG_KALLSYMS
Generate section listing all symbols and add it into vmlinux $(kallsyms.o)
It's a three stage process:
o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is
empty
Running kallsyms on that gives us .tmp_kallsyms1.o with
the right size - vmlinux version (uname -v) is updated during this step
o .tmp_vmlinux2 now has a __kallsyms section of the right size,
but due to the added section, some addresses have shifted.
From here, we generate a correct .tmp_kallsyms2.o
o The correct .tmp_kallsyms2.o is linked into the final vmlinux.
o Verify that the System.map from vmlinux matches the map from
.tmp_vmlinux2, just in case we did not generate kallsyms correctly.
o If CONFIG_KALLSYMS_EXTRA_PASS is set, do an extra pass using
.tmp_vmlinux3 and .tmp_kallsyms3.o. This is only meant as a
temporary bypass to allow the kernel to be built while the
maintainers work out what went wrong with kallsyms.
ifdef CONFIG_KALLSYMS_EXTRA_PASS last_kallsyms := 3 else last_kallsyms := 2 endif
kallsyms.o := .tmp_kallsyms$(last_kallsyms).o
define verify_kallsyms
$(Q)$(if $($(quiet)cmd_sysmap),
echo ' $($(quiet)cmd_sysmap) .tmp_System.map' &&)
$(cmd_sysmap) .tmp_vmlinux$(last_kallsyms) .tmp_System.map
$(Q)cmp -s System.map .tmp_System.map ||
(echo Inconsistent kallsyms data;
echo Try setting CONFIG_KALLSYMS_EXTRA_PASS;
rm .tmp_kallsyms* ; /bin/false )
endef
Update vmlinux version before link
Use + in front of this rule to silent warning about make -j1
First command is ':' to allow us to use + in front of this rule
cmd_ksym_ld = $(cmd_vmlinux__) define rule_ksym_ld : +$(call cmd,vmlinux_version) $(call cmd,vmlinux__) $(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd endef
Generate .S file with all kernel symbols
quiet_cmd_kallsyms = KSYM $@
cmd_kallsyms = $(NM) -n $< | $(KALLSYMS)
$(if $(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
.tmp_kallsyms1.o .tmp_kallsyms2.o .tmp_kallsyms3.o: %.o: %.S scripts FORCE $(call if_changed_dep,as_o_S)
.tmp_kallsyms%.S: .tmp_vmlinux% $(KALLSYMS) $(call cmd,kallsyms)
.tmp_vmlinux1 must be complete except kallsyms, so update vmlinux version
.tmp_vmlinux1: $(vmlinux-lds) $(vmlinux-all) FORCE $(call if_changed_rule,ksym_ld)
.tmp_vmlinux2: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms1.o FORCE $(call if_changed,vmlinux__)
.tmp_vmlinux3: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms2.o FORCE $(call if_changed,vmlinux__)
Needs to visit scripts/ before $(KALLSYMS) can be used.
$(KALLSYMS): scripts ;
Generate some data for debugging strange kallsyms problems
debug_kallsyms: .tmp_map$(last_kallsyms)
.tmp_map%: .tmp_vmlinux% FORCE ($(OBJDUMP) -h $< | $(AWK) '/^ +[0-9]/{print $$4 " 0 " $$2}'; $(NM) $<) | sort > $@
.tmp_map3: .tmp_map2
.tmp_map2: .tmp_map1
endif # ifdef CONFIG_KALLSYMS
vmlinux image - including updated kernel symbols
vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) FORCE $(call if_changed_rule,vmlinux__) $(Q)rm -f .old_version
The actual objects are generated when descending,
make sure no implicit rule kicks in
$(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ;
Handle descending into subdirectories listed in $(vmlinux-dirs)
Preset locale variables to speed up the build process. Limit locale
tweaks to this spot to avoid wrong language settings when running
make menuconfig etc.
Error messages still appears in the original language
PHONY += $(vmlinux-dirs) $(vmlinux-dirs): prepare scripts $(Q)$(MAKE) $(build)=$@
Build the kernel release string
The KERNELRELEASE is stored in a file named .kernelrelease
to be used when executing for example make install or make modules_install
Take the contents of any files called localversion* and the config
variable CONFIG_LOCALVERSION and append them to KERNELRELEASE.
LOCALVERSION from the command line override all of this
nullstring := space := $(nullstring) # end of line
___localver = $(objtree)/localversion* $(srctree)/localversion* __localver = $(sort $(wildcard $(___localver)))
skip backup files (containing '~')
_localver = $(foreach f, $(__localver), $(if $(findstring ~, $(f)),,$(f)))
localver = $(subst $(space),,
$(shell cat /dev/null $(_localver))
$(patsubst "%",%,$(CONFIG_LOCALVERSION)))
If CONFIG_LOCALVERSION_AUTO is set scripts/setlocalversion is called
and if the SCM is know a tag from the SCM is appended.
The appended tag is determinded by the SCM used.
Currently, only git is supported.
Other SCMs can edit scripts/setlocalversion and add the appropriate
checks as needed.
ifdef CONFIG_LOCALVERSION_AUTO
_localver-auto = $(shell $(CONFIG_SHELL)
$(srctree)/scripts/setlocalversion $(srctree))
localver-auto = $(LOCALVERSION)$(_localver-auto)
endif
localver-full = $(localver)$(localver-auto)
Store (new) KERNELRELASE string in .kernelrelease
kernelrelease = $(KERNELVERSION)$(localver-full) .kernelrelease: FORCE $(Q)rm -f $@ $(Q)echo $(kernelrelease) > $@
Things we need to do before we recursively start building the kernel
or the modules are listed in "prepare".
A multi level approach is used. prepareN is processed before prepareN-1.
archprepare is used in arch Makefiles and when processed asm symlink,
version.h and scripts_basic is processed / created.
Listed in dependency order
PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
prepare-all is deprecated, use prepare as valid replacement
PHONY += prepare-all
prepare3 is used to check if we are building in a separate output directory,
and if so do:
1) Check that make has not been executed in the kernel src $(srctree)
2) Create the include2 directory, used for the second asm symlink
prepare3: .kernelrelease
ifneq ($(KBUILD_SRC),)
@echo ' Using $(srctree) as source for kernel'
$(Q)if [ -f $(srctree)/.config ]; then
echo " $(srctree) is not clean, please run 'make mrproper'";
echo " in the '$(srctree)' directory.";
/bin/false;
fi;
$(Q)if [ ! -d include2 ]; then mkdir -p include2; fi;
$(Q)ln -fsn $(srctree)/include/asm-$(ARCH) include2/asm
endif
prepare2 creates a makefile if using a separate output directory
prepare2: prepare3 outputmakefile
prepare1: prepare2 include/linux/version.h include/asm
include/config/MARKER
ifneq ($(KBUILD_MODULES),)
$(Q)mkdir -p $(MODVERDIR)
$(Q)rm -f $(MODVERDIR)/*
endif
archprepare: prepare1 scripts_basic
prepare0: archprepare FORCE $(Q)$(MAKE) $(build)=.
All the preparing..
prepare prepare-all: prepare0
Leave this as default for preprocessing vmlinux.lds.S, which is now
done in arch/$(ARCH)/kernel/Makefile
export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
FIXME: The asm symlink changes when $(ARCH) changes. That's
hard to detect, but I suppose "make mrproper" is a good idea
before switching between archs anyway.
include/asm: @echo ' SYMLINK $@ -> include/asm-$(ARCH)' $(Q)if [ ! -d include ]; then mkdir -p include; fi; @ln -fsn asm-$(ARCH) $@
Split autoconf.h into include/linux/config/*
include/config/MARKER: scripts/basic/split-include include/linux/autoconf.h @echo ' SPLIT include/linux/autoconf.h -> include/config/*' @scripts/basic/split-include include/linux/autoconf.h include/config @touch $@
Generate some files
---------------------------------------------------------------------------
KERNELRELEASE can change from a few different places, meaning version.h
needs to be updated, so this check is forced on all builds
uts_len := 64
define filechk_version.h
if [ echo -n "$(KERNELRELEASE)" | wc -c -gt $(uts_len) ]; then
echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;
exit 1;
fi;
(echo #define UTS_RELEASE "$(KERNELRELEASE)";
echo #define LINUX_VERSION_CODE expr $(VERSION) \\* 65536 + $(PATCHLEVEL) \\* 256 + $(SUBLEVEL);
echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';
)
endef
include/linux/version.h: $(srctree)/Makefile .config .kernelrelease FORCE $(call filechk,version.h)
---------------------------------------------------------------------------
PHONY += depend dep depend dep: @echo '*** Warning: make $@ is unnecessary now.'
---------------------------------------------------------------------------
Modules
ifdef CONFIG_MODULES
By default, build modules as well
all: modules
Build modules
PHONY += modules modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) @echo ' Building modules, stage 2.'; $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost
Target to prepare building external modules
PHONY += modules_prepare modules_prepare: prepare scripts
Target to install modules
PHONY += modules_install modules_install: modinst _modinst_post
PHONY += modinst
modinst:
@if [ -z "$(DEPMOD) -V 2>/dev/null | grep module-init-tools" ]; then
echo "Warning: you may need to install module-init-tools";
echo "See http://www.codemonkey.org.uk/docs/post-halloween-2.6.txt";
sleep 1;
fi
@rm -rf $(MODLIB)/kernel
@rm -f $(MODLIB)/source
@mkdir -p $(MODLIB)/kernel
@ln -s $(srctree) $(MODLIB)/source
@if [ ! $(objtree) -ef $(MODLIB)/build ]; then
rm -f $(MODLIB)/build ;
ln -s $(objtree) $(MODLIB)/build ;
fi
$(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modinst
If System.map exists, run depmod. This deliberately does not have a
dependency on System.map since that would run the dependency tree on
vmlinux. This depmod is only for convenience to give the initial
boot a modules.dep even before / is mounted read-write. However the
boot script depmod is the master version.
ifeq "$(strip $(INSTALL_MOD_PATH))" "" depmod_opts := else depmod_opts := -b $(INSTALL_MOD_PATH) -r endif PHONY += _modinst_post _modinst_post: modinst if [ -r System.map -a -x $(DEPMOD) ]; then $(DEPMOD) -ae -F System.map $(depmod_opts) $(KERNELRELEASE); fi
else # CONFIG_MODULES
Modules not configured
---------------------------------------------------------------------------
modules modules_install: FORCE @echo @echo "The present kernel configuration has modules disabled." @echo "Type 'make config' and enable loadable module support." @echo "Then build a kernel with module support enabled." @echo @exit 1
endif # CONFIG_MODULES
Cleaning is done on three levels.
make clean Delete most generated files
Leave enough to build external modules
make mrproper Delete the current configuration, and all generated files
make distclean Remove editor backup files, patch leftover files and the like
Directories & files removed with 'make clean'
CLEAN_DIRS += $(MODVERDIR)
CLEAN_FILES += vmlinux System.map
.tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
Directories & files removed with 'make mrproper'
MRPROPER_DIRS += include/config include2
MRPROPER_FILES += .config .config.old include/asm .version .old_version
include/linux/autoconf.h include/linux/version.h
.kernelrelease Module.symvers tags TAGS cscope*
clean - Delete most, but leave enough to build external modules
clean: rm-dirs := $(CLEAN_DIRS) clean: rm-files := $(CLEAN_FILES) clean-dirs := $(addprefix clean,$(srctree) $(vmlinux-alldirs))
PHONY += $(clean-dirs) clean archclean $(clean-dirs): $(Q)$(MAKE) $(clean)=$(patsubst clean%,%,$@)
clean: archclean $(clean-dirs)
$(call cmd,rmdirs)
$(call cmd,rmfiles)
@find . $(RCS_FIND_IGNORE)
( -name '.[oas]' -o -name '.ko' -o -name '..cmd'
-o -name '..d' -o -name '..tmp' -o -name '.mod.c' )
-type f -print | xargs rm -f
mrproper - Delete all generated files, including .config
mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS)) mrproper: rm-files := $(wildcard $(MRPROPER_FILES)) mrproper-dirs := $(addprefix mrproper,Documentation/DocBook scripts)
PHONY += $(mrproper-dirs) mrproper archmrproper $(mrproper-dirs): $(Q)$(MAKE) $(clean)=$(patsubst mrproper%,%,$@)
mrproper: clean archmrproper $(mrproper-dirs) $(call cmd,rmdirs) $(call cmd,rmfiles)
distclean
PHONY += distclean
distclean: mrproper
@find $(srctree) $(RCS_FIND_IGNORE)
( -name '.orig' -o -name '.rej' -o -name '~'
-o -name '.bak' -o -name '##' -o -name '..orig'
-o -name '..rej' -o -size 0
-o -name '%' -o -name '.*.cmd' -o -name 'core' )
-type f -print | xargs rm -f
Packaging of the kernel to various formats
---------------------------------------------------------------------------
rpm target kept for backward compatibility
package-dir := $(srctree)/scripts/package
%pkg: FORCE $(Q)$(MAKE) $(build)=$(package-dir) $@ rpm: FORCE $(Q)$(MAKE) $(build)=$(package-dir) $@
Brief documentation of the typical targets used
---------------------------------------------------------------------------
boards := $(wildcard $(srctree)/arch/$(ARCH)/configs/*_defconfig) boards := $(notdir $(boards))
help:
@echo 'Cleaning targets:'
@echo ' clean - remove most generated files but keep the config'
@echo ' mrproper - remove all generated files + config + various backup files'
@echo ''
@echo 'Configuration targets:'
@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
@echo ''
@echo 'Other generic targets:'
@echo ' all - Build all targets marked with []'
@echo ' vmlinux - Build the bare kernel'
@echo '* modules - Build all modules'
@echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
@echo ' dir/ - Build all files in dir and below'
@echo ' dir/file.[ois] - Build specified target only'
@echo ' dir/file.ko - Build module including final link'
@echo ' rpm - Build a kernel as an RPM package'
@echo ' tags/TAGS - Generate tags file for editors'
@echo ' cscope - Generate cscope index'
@echo ' kernelrelease - Output the release version string'
@echo ' kernelversion - Output the version stored in Makefile'
@echo ''
@echo 'Static analysers'
@echo ' checkstack - Generate a list of stack hogs'
@echo ' namespacecheck - Name space analysis on compiled kernel'
@echo ''
@echo 'Kernel packaging:'
@$(MAKE) $(build)=$(package-dir) help
@echo ''
@echo 'Documentation targets:'
@$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp
@echo ''
@echo 'Architecture specific targets ($(ARCH)):'
@$(if $(archhelp),$(archhelp),
echo ' No architecture specific help defined for $(ARCH)')
@echo ''
@$(if $(boards),
$(foreach b, $(boards),
printf " %-24s - Build for %s\n" $(b) $(subst _defconfig,,$(b));)
echo '')
@echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
@echo ' make O=dir [targets] Locate all output files in "dir", including .config'
@echo ' make C=1 [targets] Check all c source with $$CHECK (sparse)'
@echo ' make C=2 [targets] Force check of all c source with $$CHECK (sparse)'
@echo ''
@echo 'Execute "make" or "make all" to build all targets marked with [*] '
@echo 'For further info see the ./README file'
Documentation targets
---------------------------------------------------------------------------
%docs: scripts_basic FORCE $(Q)$(MAKE) $(build)=Documentation/DocBook $@
else # KBUILD_EXTMOD
External module support.
When building external modules the kernel used as basis is considered
read-only, and no consistency checks are made and the make
system is not used on the basis kernel. If updates are required
in the basis kernel ordinary make commands (without M=...) must
be used.
The following are the only valid targets when building external
modules.
make M=dir clean Delete all automatically generated files
make M=dir modules Make all modules in specified dir
make M=dir Same as 'make M=dir modules'
make M=dir modules_install
Install the modules build in the module directory
Assumes install directory is already created
We are always building modules
KBUILD_MODULES := 1 PHONY += crmodverdir crmodverdir: $(Q)mkdir -p $(MODVERDIR) $(Q)rm -f $(MODVERDIR)/*
PHONY += $(objtree)/Module.symvers
$(objtree)/Module.symvers:
@test -e $(objtree)/Module.symvers || (
echo;
echo " WARNING: Symbol version dump $(objtree)/Module.symvers";
echo " is missing; modules will have no dependencies and modversions.";
echo )
module-dirs := $(addprefix module,$(KBUILD_EXTMOD)) PHONY += $(module-dirs) modules $(module-dirs): crmodverdir $(objtree)/Module.symvers $(Q)$(MAKE) $(build)=$(patsubst module%,%,$@)
modules: $(module-dirs) @echo ' Building modules, stage 2.'; $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost
PHONY += modules_install modules_install: emodinst _emodinst_post
install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra) PHONY += emodinst emodinst: $(Q)mkdir -p $(MODLIB)/$(install-dir) $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modinst
Run depmod only is we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = if [ -r System.map -a -x $(DEPMOD) ]; then
$(DEPMOD) -ae -F System.map
$(if $(strip $(INSTALL_MOD_PATH)),
-b $(INSTALL_MOD_PATH) -r)
$(KERNELRELEASE);
fi
PHONY += _emodinst_post _emodinst_post: emodinst $(call cmd,depmod)
clean-dirs := $(addprefix clean,$(KBUILD_EXTMOD))
PHONY += $(clean-dirs) clean $(clean-dirs): $(Q)$(MAKE) $(clean)=$(patsubst clean%,%,$@)
clean: rm-dirs := $(MODVERDIR)
clean: $(clean-dirs)
$(call cmd,rmdirs)
@find $(KBUILD_EXTMOD) $(RCS_FIND_IGNORE)
( -name '.[oas]' -o -name '.ko' -o -name '..cmd'
-o -name '..d' -o -name '..tmp' -o -name '.mod.c' )
-type f -print | xargs rm -f
help: @echo ' Building external modules.' @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target' @echo '' @echo ' modules - default target, build the module(s)' @echo ' modules_install - install the module' @echo ' clean - remove generated files in module directory only' @echo ''
Dummies...
PHONY += prepare scripts prepare: ; scripts: ; endif # KBUILD_EXTMOD
Generate tags for editors
---------------------------------------------------------------------------
#We want __srctree to totally vanish out when KBUILD_OUTPUT is not set #(which is the most common case IMHO) to avoid unneeded clutter in the big tags file. #Adding $(srctree) adds about 20M on i386 to the size of the output file!
ifeq ($(src),$(obj)) __srctree = else __srctree = $(srctree)/ endif
ifeq ($(ALLSOURCE_ARCHS),) ifeq ($(ARCH),um) ALLINCLUDE_ARCHS := $(ARCH) $(SUBARCH) else ALLINCLUDE_ARCHS := $(ARCH) endif else #Allow user to specify only ALLSOURCE_PATHS on the command line, keeping existing behaviour. ALLINCLUDE_ARCHS := $(ALLSOURCE_ARCHS) endif
ALLSOURCE_ARCHS := $(ARCH)
define all-sources
( find $(__srctree) $(RCS_FIND_IGNORE)
-name include -o -name arch -prune -o
-name '.[chS]' -print;
for ARCH in $(ALLSOURCE_ARCHS) ; do
find $(__srctree)arch/$${ARCH} $(RCS_FIND_IGNORE)
-name '.[chS]' -print;
done ;
find $(__srctree)security/selinux/include $(RCS_FIND_IGNORE)
-name '.[chS]' -print;
find $(__srctree)include $(RCS_FIND_IGNORE)
-name config -o -name 'asm-*' -prune
-o -name '.[chS]' -print;
for ARCH in $(ALLINCLUDE_ARCHS) ; do
find $(__srctree)include/asm-$${ARCH} $(RCS_FIND_IGNORE)
-name '.[chS]' -print;
done ;
find $(__srctree)include/asm-generic $(RCS_FIND_IGNORE)
-name '.[chS]' -print )
endef
quiet_cmd_cscope-file = FILELST cscope.files cmd_cscope-file = (echo -k; echo -q; $(all-sources)) > cscope.files
quiet_cmd_cscope = MAKE cscope.out cmd_cscope = cscope -b
cscope: FORCE $(call cmd,cscope-file) $(call cmd,cscope)
quiet_cmd_TAGS = MAKE $@
define cmd_TAGS
rm -f $@;
ETAGSF=etags --version | grep -i exuberant >/dev/null && \ echo "-I __initdata,__exitdata,__acquires,__releases \ -I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL \ --extra=+f --c-kinds=+px";
$(all-sources) | xargs etags $$ETAGSF -a
endef
TAGS: FORCE $(call cmd,TAGS)
quiet_cmd_tags = MAKE $@
define cmd_tags
rm -f $@;
CTAGSF=ctags --version | grep -i exuberant >/dev/null && \ echo "-I __initdata,__exitdata,__acquires,__releases \ -I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL \ --extra=+f --c-kinds=+px";
$(all-sources) | xargs ctags $$CTAGSF -a
endef
tags: FORCE $(call cmd,tags)
Scripts to check various things for consistency
---------------------------------------------------------------------------
includecheck:
find * $(RCS_FIND_IGNORE)
-name '*.[hcS]' -type f -print | sort
| xargs $(PERL) -w scripts/checkincludes.pl
versioncheck:
find * $(RCS_FIND_IGNORE)
-name '*.[hcS]' -type f -print | sort
| xargs $(PERL) -w scripts/checkversion.pl
namespacecheck: $(PERL) $(srctree)/scripts/namespace.pl
endif #ifeq ($(config-targets),1) endif #ifeq ($(mixed-targets),1)
PHONY += checkstack
checkstack:
$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') |
$(PERL) $(src)/scripts/checkstack.pl $(ARCH)
kernelrelease:
$(if $(wildcard .kernelrelease), $(Q)echo $(KERNELRELEASE),
$(error kernelrelease not valid - run 'make *config' to update it))
kernelversion:
@echo $(KERNELVERSION)
Single targets
---------------------------------------------------------------------------
Single targets are compatible with:
- build whith mixed source and output
- build with separate output dir 'make O=...'
- external modules
target-dir => where to store outputfile
build-dir => directory in kernel source tree to use
ifeq ($(KBUILD_EXTMOD),) build-dir = $(patsubst %/,%,$(dir $@)) target-dir = $(dir $@) else zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@))) build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash)) target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@)) endif
%.s: %.c prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@) %.i: %.c prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@) %.o: %.c prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@) %.lst: %.c prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@) %.s: %.S prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@) %.o: %.S prepare scripts FORCE $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
Modules
/ %/: prepare scripts FORCE
$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)
$(build)=$(build-dir)
%.ko: prepare scripts FORCE
$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)
$(build)=$(build-dir) $(@:.ko=.o)
$(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost
FIXME Should go into a make.lib or something
===========================================================================
quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs))) cmd_rmdirs = rm -rf $(rm-dirs)
quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))) cmd_rmfiles = rm -f $(rm-files)
a_flags = -Wp,-MD,$(depfile) $(AFLAGS) $(AFLAGS_KERNEL)
$(NOSTDINC_FLAGS) $(CPPFLAGS)
$(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(*F).o)
quiet_cmd_as_o_S = AS $@ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
read all saved command lines
targets := $(wildcard $(sort $(targets))) cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),) $(cmd_files): ; # Do not try to update included dependency files include $(cmd_files) endif
Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=dir
Usage:
$(Q)$(MAKE) $(clean)=dir
clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
endif # skip-makefile
PHONY += FORCE FORCE:
Declare the contents of the .PHONY variable as phony. We keep that
information in a variable se we can use it in if_changed and friends.
.PHONY: $(PHONY)