immortalwrt/include/kernel-defaults.mk
Eneas U de Queiroz 3c3cbd9214 build: kernel: avoid unnecessary package rebuilds
The $(LINUX_DIR)/.config timesptamp changes between runs of
make target/compile and make target/install (which builds the image).

Kernel-dependent packages and out of tree modules are built in between
those runs, and they check the .config timestamp to decide if they need
to be rebuilt.

Save the target/compile .config to use its timestamp if the file does
not change between runs.  That way the subsequent kernel packages are
not unnecessarily rebuilt when you run 'make' back to back.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>
2021-11-16 13:15:41 +08:00

165 lines
7.2 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2006-2020 OpenWrt.org
ifdef CONFIG_STRIP_KERNEL_EXPORTS
KERNEL_MAKEOPTS += \
EXTRA_LDSFLAGS="-I$(KERNEL_BUILD_DIR) -include symtab.h"
endif
INITRAMFS_EXTRA_FILES ?= $(GENERIC_PLATFORM_DIR)/image/initramfs-base-files.txt
ifneq (,$(KERNEL_CC))
KERNEL_MAKEOPTS += CC="$(KERNEL_CC)"
endif
export HOST_EXTRACFLAGS=-I$(STAGING_DIR_HOST)/include
# defined in quilt.mk
Kernel/Patch:=$(Kernel/Patch/Default)
ifneq (,$(findstring .xz,$(LINUX_SOURCE)))
LINUX_CAT:=xzcat
else
LINUX_CAT:=zcat
endif
ifeq ($(strip $(CONFIG_EXTERNAL_KERNEL_TREE)),"")
ifeq ($(strip $(CONFIG_KERNEL_GIT_CLONE_URI)),"")
define Kernel/Prepare/Default
$(LINUX_CAT) $(DL_DIR)/$(LINUX_SOURCE) | $(TAR) -C $(KERNEL_BUILD_DIR) $(TAR_OPTIONS)
$(Kernel/Patch)
$(if $(QUILT),touch $(LINUX_DIR)/.quilt_used)
endef
else
define Kernel/Prepare/Default
$(LINUX_CAT) $(DL_DIR)/$(LINUX_SOURCE) | $(TAR) -C $(KERNEL_BUILD_DIR) $(TAR_OPTIONS)
endef
endif
else
define Kernel/Prepare/Default
mkdir -p $(KERNEL_BUILD_DIR)
if [ -d $(LINUX_DIR) ]; then \
rmdir $(LINUX_DIR); \
fi
ln -s $(CONFIG_EXTERNAL_KERNEL_TREE) $(LINUX_DIR)
endef
endif
ifeq ($(CONFIG_TARGET_ROOTFS_INITRAMFS),y)
ifeq ($(strip $(CONFIG_EXTERNAL_CPIO)),"")
define Kernel/SetInitramfs/PreConfigure
grep -v -e INITRAMFS -e CONFIG_RD_ -e CONFIG_BLK_DEV_INITRD $(LINUX_DIR)/.config.old > $(LINUX_DIR)/.config
echo 'CONFIG_BLK_DEV_INITRD=y' >> $(LINUX_DIR)/.config
echo 'CONFIG_INITRAMFS_SOURCE="$(strip $(TARGET_DIR) $(INITRAMFS_EXTRA_FILES))"' >> $(LINUX_DIR)/.config
endef
else
define Kernel/SetInitramfs/PreConfigure
grep -v INITRAMFS $(LINUX_DIR)/.config.old > $(LINUX_DIR)/.config
echo 'CONFIG_INITRAMFS_SOURCE="$(call qstrip,$(CONFIG_EXTERNAL_CPIO))"' >> $(LINUX_DIR)/.config
endef
endif
define Kernel/SetInitramfs
rm -f $(LINUX_DIR)/.config.prev
mv $(LINUX_DIR)/.config $(LINUX_DIR)/.config.old
$(call Kernel/SetInitramfs/PreConfigure)
echo 'CONFIG_INITRAMFS_ROOT_UID=$(shell id -u)' >> $(LINUX_DIR)/.config
echo 'CONFIG_INITRAMFS_ROOT_GID=$(shell id -g)' >> $(LINUX_DIR)/.config
echo "$(if $(CONFIG_TARGET_INITRAMFS_FORCE),CONFIG_INITRAMFS_FORCE=y,# CONFIG_INITRAMFS_FORCE is not set)" >> $(LINUX_DIR)/.config
echo "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_NONE),CONFIG_INITRAMFS_COMPRESSION_NONE=y,# CONFIG_INITRAMFS_COMPRESSION_NONE is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_GZIP),CONFIG_INITRAMFS_COMPRESSION_GZIP=y\nCONFIG_RD_GZIP=y,# CONFIG_INITRAMFS_COMPRESSION_GZIP is not set\n# CONFIG_RD_GZIP is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_BZIP2),CONFIG_INITRAMFS_COMPRESSION_BZIP2=y\nCONFIG_RD_BZIP2=y,# CONFIG_INITRAMFS_COMPRESSION_BZIP2 is not set\n# CONFIG_RD_BZIP2 is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZMA),CONFIG_INITRAMFS_COMPRESSION_LZMA=y\nCONFIG_RD_LZMA=y,# CONFIG_INITRAMFS_COMPRESSION_LZMA is not set\n# CONFIG_RD_LZMA is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZO),CONFIG_INITRAMFS_COMPRESSION_LZO=y\nCONFIG_RD_LZO=y,# CONFIG_INITRAMFS_COMPRESSION_LZO is not set\n# CONFIG_RD_LZO is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_XZ),CONFIG_INITRAMFS_COMPRESSION_XZ=y\nCONFIG_RD_XZ=y,# CONFIG_INITRAMFS_COMPRESSION_XZ is not set\n# CONFIG_RD_XZ is not set)" >> $(LINUX_DIR)/.config
echo -e "$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZ4),CONFIG_INITRAMFS_COMPRESSION_LZ4=y\nCONFIG_RD_LZ4=y,# CONFIG_INITRAMFS_COMPRESSION_LZ4 is not set\n# CONFIG_RD_LZ4 is not set)" >> $(LINUX_DIR)/.config
endef
else
endif
define Kernel/SetNoInitramfs
mv $(LINUX_DIR)/.config.set $(LINUX_DIR)/.config.old
grep -v INITRAMFS $(LINUX_DIR)/.config.old > $(LINUX_DIR)/.config.set
echo 'CONFIG_INITRAMFS_SOURCE=""' >> $(LINUX_DIR)/.config.set
echo '# CONFIG_INITRAMFS_FORCE is not set' >> $(LINUX_DIR)/.config.set
endef
define Kernel/Configure/Default
rm -f $(LINUX_DIR)/localversion
$(LINUX_CONF_CMD) > $(LINUX_DIR)/.config.target
# copy CONFIG_KERNEL_* settings over to .config.target
awk '/^(#[[:space:]]+)?CONFIG_KERNEL/{sub("CONFIG_KERNEL_","CONFIG_");print}' $(TOPDIR)/.config >> $(LINUX_DIR)/.config.target
echo "# CONFIG_KALLSYMS_EXTRA_PASS is not set" >> $(LINUX_DIR)/.config.target
echo "# CONFIG_KALLSYMS_ALL is not set" >> $(LINUX_DIR)/.config.target
echo "CONFIG_KALLSYMS_UNCOMPRESSED=y" >> $(LINUX_DIR)/.config.target
$(SCRIPT_DIR)/package-metadata.pl kconfig $(TMP_DIR)/.packageinfo $(TOPDIR)/.config $(KERNEL_PATCHVER) > $(LINUX_DIR)/.config.override
$(SCRIPT_DIR)/kconfig.pl 'm+' '+' $(LINUX_DIR)/.config.target /dev/null $(LINUX_DIR)/.config.override > $(LINUX_DIR)/.config.set
$(call Kernel/SetNoInitramfs)
rm -rf $(KERNEL_BUILD_DIR)/modules
cmp -s $(LINUX_DIR)/.config.set $(LINUX_DIR)/.config.prev || { \
cp $(LINUX_DIR)/.config.set $(LINUX_DIR)/.config; \
cp $(LINUX_DIR)/.config.set $(LINUX_DIR)/.config.prev; \
}
$(_SINGLE) [ -d $(LINUX_DIR)/user_headers ] || $(KERNEL_MAKE) INSTALL_HDR_PATH=$(LINUX_DIR)/user_headers headers_install
grep '=[ym]' $(LINUX_DIR)/.config.set | LC_ALL=C sort | $(MKHASH) md5 > $(LINUX_DIR)/.vermagic
endef
define Kernel/Configure/Initramfs
$(call Kernel/SetInitramfs)
endef
define Kernel/CompileModules/Default
rm -f $(LINUX_DIR)/vmlinux $(LINUX_DIR)/System.map
+$(KERNEL_MAKE) modules
# If .config did not change, use the previous timestamp to avoid package rebuilds
cmp -s $(LINUX_DIR)/.config $(LINUX_DIR)/.config.modules.save && \
mv $(LINUX_DIR)/.config.modules.save $(LINUX_DIR)/.config; \
$(CP) $(LINUX_DIR)/.config $(LINUX_DIR)/.config.modules.save
endef
OBJCOPY_STRIP = -R .reginfo -R .notes -R .note -R .comment -R .mdebug -R .note.gnu.build-id
# AMD64 shares the location with x86
ifeq ($(LINUX_KARCH),x86_64)
IMAGES_DIR:=../../x86/boot
endif
define Kernel/CopyImage
cmp -s $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug || { \
$(KERNEL_CROSS)objcopy -O binary $(OBJCOPY_STRIP) -S $(LINUX_DIR)/vmlinux $(LINUX_KERNEL)$(1); \
$(KERNEL_CROSS)objcopy $(OBJCOPY_STRIP) -S $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).elf; \
$(CP) $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug; \
$(foreach k, \
$(if $(KERNEL_IMAGES),$(KERNEL_IMAGES),$(filter-out vmlinux dtbs,$(KERNELNAME))), \
$(CP) $(LINUX_DIR)/arch/$(LINUX_KARCH)/boot/$(IMAGES_DIR)/$(k) $(KERNEL_BUILD_DIR)/$(k)$(1); \
) \
}
endef
define Kernel/CompileImage/Default
rm -f $(TARGET_DIR)/init
+$(KERNEL_MAKE) $(if $(KERNELNAME),$(KERNELNAME),all) modules
$(call Kernel/CopyImage)
endef
ifneq ($(CONFIG_TARGET_ROOTFS_INITRAMFS),)
define Kernel/CompileImage/Initramfs
$(call Kernel/Configure/Initramfs)
$(CP) $(GENERIC_PLATFORM_DIR)/other-files/init $(TARGET_DIR)/init
$(if $(SOURCE_DATE_EPOCH),touch -hcd "@$(SOURCE_DATE_EPOCH)" $(TARGET_DIR)/init)
rm -rf $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/usr/initramfs_data.cpio*
+$(KERNEL_MAKE) $(if $(KERNELNAME),$(KERNELNAME),all) modules
$(call Kernel/CopyImage,-initramfs)
endef
else
define Kernel/CompileImage/Initramfs
endef
endif
define Kernel/Clean/Default
rm -f $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/.configured
rm -f $(LINUX_KERNEL)
$(_SINGLE)$(MAKE) -C $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION) clean
endef