u-boot/arch/blackfin/config.mk
Masahiro Yamada 026f9cf24f kbuild: improve Kbuild speed
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]
2014-03-07 10:59:06 -05:00

70 lines
1.8 KiB
Makefile

#
# (C) Copyright 2000-2002
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# SPDX-License-Identifier: GPL-2.0+
#
ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := bfin-uclinux-
endif
CONFIG_STANDALONE_LOAD_ADDR ?= 0x1000 -m elf32bfin
ifeq ($(CONFIG_BFIN_CPU),)
CONFIG_BFIN_CPU := \
$(shell awk '$$2 == "CONFIG_BFIN_CPU" { print $$3 }' \
$(srctree)/include/configs/$(BOARD).h)
else
CONFIG_BFIN_CPU := $(strip $(CONFIG_BFIN_CPU:"%"=%))
endif
CONFIG_BFIN_BOOT_MODE := $(strip $(CONFIG_BFIN_BOOT_MODE:"%"=%))
PLATFORM_RELFLAGS += -ffixed-P3 -fomit-frame-pointer -mno-fdpic
PLATFORM_CPPFLAGS += -DCONFIG_BLACKFIN
LDFLAGS_FINAL += --gc-sections
LDFLAGS += -m elf32bfin
PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections
PLATFORM_RELFLAGS += -mcpu=$(CONFIG_BFIN_CPU)
ifneq ($(CONFIG_BFIN_BOOT_MODE),BFIN_BOOT_BYPASS)
ALL-y += u-boot.ldr
endif
ifeq ($(CONFIG_ENV_IS_EMBEDDED_IN_LDR),y)
CREATE_LDR_ENV = tools/envcrc --binary > env-ldr.o
HOSTCFLAGS_NOPED_ADSP := \
$(shell $(CPP) -dD - -mcpu=$(CONFIG_BFIN_CPU) </dev/null \
| awk '$$2 ~ /ADSP/ { print "-D" $$2 }')
HOSTCFLAGS_NOPED += $(HOSTCFLAGS_NOPED_ADSP)
else
CREATE_LDR_ENV =
endif
SYM_PREFIX = _
export SYM_PREFIX
LDR_FLAGS-y :=
LDR_FLAGS-$(CONFIG_BFIN_BOOTROM_USES_EVT1) += -J
LDR_FLAGS += --bmode $(subst BFIN_BOOT_,,$(CONFIG_BFIN_BOOT_MODE))
LDR_FLAGS += --use-vmas
LDR_FLAGS += --initcode $(CPUDIR)/initcode.o
ifneq ($(CONFIG_BFIN_BOOT_MODE),BFIN_BOOT_UART)
LDR_FLAGS-$(CONFIG_ENV_IS_EMBEDDED_IN_LDR) += \
--punchit $$(($(CONFIG_ENV_OFFSET))):$$(($(CONFIG_ENV_SIZE))):env-ldr.o
endif
ifneq (,$(findstring s,$(MAKEFLAGS)))
LDR_FLAGS += --quiet
endif
LDR_FLAGS += $(LDR_FLAGS-y)
# Set some default LDR flags based on boot mode.
LDR_FLAGS += $(LDR_FLAGS-$(CONFIG_BFIN_BOOT_MODE))
ifneq ($(CONFIG_SYS_TEXT_BASE),)
$(error do not set CONFIG_SYS_TEXT_BASE for Blackfin boards)
endif