leandrof/u-boot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

kbuild: improve Kbuild speed

Browse Source 
Kbuild brought about many advantages for us but a significant
performance regression was reported by Simon Glass.

After some discussions and analysis, it turned out
its main cause is in $(call cc-option,...).

Historically, U-Boot parses all config.mk
(arch/*/config.mk and board/*/config.mk)
every time descending into subdirectories.
That means cc-options are evaluated over and over again.

$(call cc-option,...) is useful but costly.
So we want to evaluate them only in ./Makefile
and spl/Makefile and export compiler flags.

This commit changes the build system as follows:

  - Modify scripts/Makefile.build to not include config.mk
    Instead, add $(PLATFORM_CPPFLAGS) to asflags-y, ccflags-y,
    cppflags-y.

  - Export many variables
    Going forward, Kbuild will not parse config.mk files
    when it descends into subdirectories.
    If we want to set variables in config.mk and use them
    in subdirectories, they must be exported.

    This is the list of variables to get exported:
      PLATFORM_CPPFLAGS
      CPUDIR
      BOARDDIR
      OBJCOPYFLAGS
      LDFLAGS
      LDFLAGS_FINAL
        (used in nand_spl/board/*/*/Makefile)
      CONFIG_STANDALONE_LOAD_ADDR
        (used in examples/standalone/Makefile)
      SYM_PREFIX
        (used in examples/standalone/Makefile)
      RELFLAGS
        (used in examples/standalone/Makefile)

  - Delete CPPFLAGS
    This variable has been replaced with PLATFORM_CPPFLAGS

  - Copy gcclibdir from example/standalone/Makefile
    to arch/sparc/config.mk
    The reference in CONFIG_STANDALONE_LOAD_ADDR must be
    resolved before it is exported.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> [on Sandbox]
Tested-by: Stephen Warren <swarren@nvidia.com> [on Tegra]
This commit is contained in:
Masahiro Yamada 2014-03-05 16:59:40 +09:00 committed by Tom Rini
parent a0a15b441c
commit 026f9cf24f
8 changed files with 44 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Makefile
View File

@ -358,13 +358,13 @@ UBOOTRELEASE = $(shell cat include/config/uboot.release 2> /dev/null)
UBOOTVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
export VERSION PATCHLEVEL SUBLEVEL UBOOTRELEASE UBOOTVERSION
export ARCH CPU BOARD VENDOR SOC
export ARCH CPU BOARD VENDOR SOC CPUDIR BOARDDIR
export CONFIG_SHELL HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM LDR STRIP OBJCOPY OBJDUMP
export MAKE AWK
export DTC CHECK CHECKFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS UBOOTINCLUDE
export KBUILD_CPPFLAGS NOSTDINC_FLAGS UBOOTINCLUDE OBJCOPYFLAGS LDFLAGS
export KBUILD_CFLAGS KBUILD_AFLAGS
# When compiling out-of-tree modules, put MODVERDIR in the module
@ -567,7 +567,8 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
CHECKFLAGS += $(NOSTDINC_FLAGS)
# FIX ME
cpp_flags := $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
cpp_flags := $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) $(UBOOTINCLUDE) \
$(NOSTDINC_FLAGS)
c_flags := $(KBUILD_CFLAGS) $(cpp_flags)
#########################################################################

1
arch/blackfin/config.mk
View File

@ -43,6 +43,7 @@ CREATE_LDR_ENV =
endif
SYM_PREFIX = _
export SYM_PREFIX
LDR_FLAGS-y :=
LDR_FLAGS-$(CONFIG_BFIN_BOOTROM_USES_EVT1) += -J

2
arch/sparc/config.mk
View File

@ -9,6 +9,8 @@ ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := sparc-elf-
endif
gcclibdir := $(shell dirname `$(CC) -print-libgcc-file-name`)
CONFIG_STANDALONE_LOAD_ADDR ?= 0x00000000 -L $(gcclibdir) \
-T $(srctree)/examples/standalone/sparc.lds

28
config.mk
View File

@ -6,11 +6,18 @@
#
#########################################################################
# clean the slate ...
PLATFORM_RELFLAGS =
PLATFORM_CPPFLAGS =
PLATFORM_LDFLAGS =
# This file is included from ./Makefile and spl/Makefile.
# Clean the state to avoid the same flags added twice.
#
# (Tegra needs different flags for SPL.
# That's the reason why this file must be included from spl/Makefile too.
# If we did not have Tegra SoCs, build system would be much simpler...)
PLATFORM_RELFLAGS :=
PLATFORM_CPPFLAGS :=
PLATFORM_LDFLAGS :=
LDFLAGS :=
LDFLAGS_FINAL :=
OBJCOPYFLAGS :=
#########################################################################
# Some architecture config.mk files need to know what CPUDIR is set to,
@ -41,12 +48,17 @@ endif
#########################################################################
RELFLAGS= $(PLATFORM_RELFLAGS)
RELFLAGS := $(PLATFORM_RELFLAGS)
OBJCOPYFLAGS += --gap-fill=0xff
CPPFLAGS = $(RELFLAGS)
CPPFLAGS += -pipe $(PLATFORM_CPPFLAGS)
PLATFORM_CPPFLAGS += $(RELFLAGS)
PLATFORM_CPPFLAGS += -pipe
LDFLAGS += $(PLATFORM_LDFLAGS)
LDFLAGS_FINAL += -Bstatic
export PLATFORM_CPPFLAGS
export RELFLAGS
export LDFLAGS_FINAL
export CONFIG_STANDALONE_LOAD_ADDR

5
examples/standalone/Makefile
View File

@ -44,9 +44,8 @@ gcclibdir := $(shell dirname `$(CC) -print-libgcc-file-name`)
# relocatable executable. The relocation data is not needed, and
# also causes the entry point of the standalone application to be
# inconsistent.
ifeq ($(ARCH),powerpc)
# FIX ME
CPPFLAGS := $(filter-out $(RELFLAGS), $(CPPFLAGS))
ifeq ($(CONFIG_PPC),y)
PLATFORM_CPPFLAGS := $(filter-out $(RELFLAGS),$(PLATFORM_CPPFLAGS))
endif
# We don't want gcc reordering functions if possible. This ensures that an

10
scripts/Makefile.build
View File

@ -55,11 +55,6 @@ endif
include scripts/Kbuild.include
# Added for U-Boot
# We must include config.mk after Kbuild.include
# so that some config.mk can use cc-option.
include config.mk
# For backward compatibility check that these variables do not change
save-cflags := $(CFLAGS)
@ -68,6 +63,11 @@ kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
include $(kbuild-file)
# Added for U-Boot
asflags-y += $(PLATFORM_CPPFLAGS)
ccflags-y += $(PLATFORM_CPPFLAGS)
cppflags-y += $(PLATFORM_CPPFLAGS)
# If the save-* variables changed error out
ifeq ($(KBUILD_NOPEDANTIC),)
ifneq ("$(save-cflags)","$(CFLAGS)")

7
scripts/Makefile.lib
View File

@ -101,13 +101,12 @@ basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))"
modname_flags = $(if $(filter 1,$(words $(modname))),\
-D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")
# U-Boot also uses $(CPPFLAGS)
orig_c_flags = $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
$(ccflags-y) $(CFLAGS_$(basetarget).o)
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
_a_flags = $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
$(asflags-y) $(AFLAGS_$(basetarget).o)
_cpp_flags = $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
#
# Enable gcov profiling flags for a file, directory or for all files depending

15
spl/Makefile
View File

@ -29,10 +29,6 @@ ifeq ($(CONFIG_TPL_BUILD),y)
KBUILD_CPPFLAGS += -DCONFIG_TPL_BUILD
endif
# Enable garbage collection of un-used sections for SPL
KBUILD_CFLAGS += -ffunction-sections -fdata-sections
LDFLAGS_FINAL += --gc-sections
ifeq ($(CONFIG_TPL_BUILD),y)
export CONFIG_TPL_BUILD
SPL_BIN := u-boot-tpl
@ -50,8 +46,14 @@ endif
include $(TOPDIR)/config.mk
# Enable garbage collection of un-used sections for SPL
KBUILD_CFLAGS += -ffunction-sections -fdata-sections
LDFLAGS_FINAL += --gc-sections
# FIX ME
c_flags := $(KBUILD_CFLAGS) $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
cpp_flags := $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) $(UBOOTINCLUDE) \
$(NOSTDINC_FLAGS)
c_flags := $(KBUILD_CFLAGS) $(cpp_flags)
# Auto-generate the spl-autoconf.mk file (which is included by all makefiles for SPL)
quiet_cmd_autoconf = GEN $@
@ -228,9 +230,6 @@ PHONY += $(u-boot-spl-dirs)
$(u-boot-spl-dirs):
$(Q)$(MAKE) $(build)=$@
# FIX ME
cpp_flags := $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
quiet_cmd_cpp_lds = LDS $@
cmd_cpp_lds = $(CPP) $(cpp_flags) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ \
-x assembler-with-cpp -P -o $@ $<