Openwrt/include/kernel-defaults.mk
Felix Fietkau 3bbb927728 build: Allow kernel modules to set build ID debug symbol
This change adds support for specifying a build ID for kernel modules.
This is done by setting PKG_BUILD_ID to a hexadecimal string, which will
then be passed to the kernel linker. In addition, when this flag is set,
the build ID debug symbol (.note.gnu.build-id) will not be stripped from
the kernel module. This symbol is exported in sysfs by the kernel (if
the kernel is compiled with CONFIG_KALLSYMS) and so can be used to
uniquely identify a version of a kernel module in a running kernel. This
is useful for keeping track of different versions of a module when doing
experiments and development.

Modules that specify the build ID will be ~100 bytes larger (depending
on the length of the build ID specified). There is no size difference
for kernel modules that do not set this variable.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

SVN-Revision: 47290
2015-10-30 15:20:12 +00:00

171 lines
7.0 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 \
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)
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
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 $(LINUX_DIR)/.config.old
grep -v INITRAMFS $(LINUX_DIR)/.config.old > $(LINUX_DIR)/.config
echo 'CONFIG_INITRAMFS_SOURCE=""' >> $(LINUX_DIR)/.config
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 is not set" >> $(LINUX_DIR)/.config.target
$(SCRIPT_DIR)/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
$(call Kernel/SetNoInitramfs)
rm -rf $(KERNEL_BUILD_DIR)/modules
$(_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 | 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
$(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.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