Openwrt/include/kernel-defaults.mk
Jonas Gorski 5fe923b15d kernel: allow reproducable builds
Similar how we fix the file times in the filesystems, fix the build time
of the kernel, and make the build number static. This should allow the
kernel build to be reproducable when combined with setting the
KERNEL_BUILD_USER and _DOMAIN in case of different machines.

The reproducability only applies to non-initramfs kernels, those still
require additional changes.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
2016-08-13 11:35:00 +02:00

182 lines
7.6 KiB
Makefile

#
# Copyright (C) 2006-2015 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#
KERNEL_MAKEOPTS := -C $(LINUX_DIR) \
HOSTCFLAGS="$(HOST_CFLAGS) -Wall -Wmissing-prototypes -Wstrict-prototypes" \
CROSS_COMPILE="$(KERNEL_CROSS)" \
ARCH="$(LINUX_KARCH)" \
KBUILD_HAVE_NLS=no \
KBUILD_BUILD_USER="$(call qstrip,$(CONFIG_KERNEL_BUILD_USER))" \
KBUILD_BUILD_HOST="$(call qstrip,$(CONFIG_KERNEL_BUILD_DOMAIN))" \
KBUILD_BUILD_TIMESTAMP="$(shell date -u --date="@$(SOURCE_DATE_EPOCH)")" \
KBUILD_BUILD_VERSION="0" \
CONFIG_SHELL="$(BASH)" \
$(if $(findstring c,$(OPENWRT_VERBOSE)),V=1,V='') \
$(if $(PKG_BUILD_ID),LDFLAGS_MODULE=--build-id=0x$(PKG_BUILD_ID))
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="$(KERNEL_CC)"
endif
ifdef CONFIG_USE_SPARSE
KERNEL_MAKEOPTS += C=1 CHECK=$(STAGING_DIR_HOST)/bin/sparse
endif
export HOST_EXTRACFLAGS=-I$(STAGING_DIR_HOST)/include
# defined in quilt.mk
Kernel/Patch:=$(Kernel/Patch/Default)
KERNEL_GIT_OPTS:=
ifneq ($(strip $(CONFIG_KERNEL_GIT_LOCAL_REPOSITORY)),"")
KERNEL_GIT_OPTS+=--reference $(CONFIG_KERNEL_GIT_LOCAL_REPOSITORY)
endif
ifneq ($(strip $(CONFIG_KERNEL_GIT_BRANCH)),"")
KERNEL_GIT_OPTS+=--branch $(CONFIG_KERNEL_GIT_BRANCH)
endif
ifeq ($(strip $(CONFIG_EXTERNAL_KERNEL_TREE)),"")
ifeq ($(strip $(CONFIG_KERNEL_GIT_CLONE_URI)),"")
define Kernel/Prepare/Default
xzcat $(DL_DIR)/$(LINUX_SOURCE) | $(TAR) -C $(KERNEL_BUILD_DIR) $(TAR_OPTIONS)
$(Kernel/Patch)
$(if $(QUILT),touch $(LINUX_DIR)/.quilt_used)
endef
else
define Kernel/Prepare/Default
git clone $(KERNEL_GIT_OPTS) $(CONFIG_KERNEL_GIT_CLONE_URI) $(LINUX_DIR)
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_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
endef
define Kernel/Configure/Default
$(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 ] || $(MAKE) $(KERNEL_MAKEOPTS) INSTALL_HDR_PATH=$(LINUX_DIR)/user_headers headers_install
$(SH_FUNC) grep '=[ym]' $(LINUX_DIR)/.config.set | LC_ALL=C sort | md5s > $(LINUX_DIR)/.vermagic
endef
define Kernel/Configure/Initramfs
$(call Kernel/SetInitramfs)
endef
define Kernel/CompileModules/Default
rm -f $(LINUX_DIR)/vmlinux $(LINUX_DIR)/System.map
+$(MAKE) $(KERNEL_MAKEOPTS) modules
endef
OBJCOPY_STRIP = -R .reginfo -R .notes -R .note -R .comment -R .mdebug -R .note.gnu.build-id
# AMD64 shares the location with x86
ifeq ($(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),$(filter-out dtbs,$(KERNELNAME))), \
$(CP) $(LINUX_DIR)/arch/$(LINUX_KARCH)/boot/$(IMAGES_DIR)/$(k) $(KERNEL_BUILD_DIR)/$(k)$(1); \
) \
}
endef
define Kernel/CompileImage/Default
rm -f $(TARGET_DIR)/init
+$(MAKE) $(KERNEL_MAKEOPTS) $(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)/base-files/init $(TARGET_DIR)/init
rm -rf $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/usr/initramfs_data.cpio*
+$(MAKE) $(KERNEL_MAKEOPTS) $(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