buildroot/linux/linux.mk

340 lines
12 KiB
Makefile
Raw Normal View History

################################################################################
#
# Linux kernel target
#
################################################################################
LINUX_VERSION = $(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
LINUX_LICENSE = GPLv2
LINUX_LICENSE_FILES = COPYING
# Compute LINUX_SOURCE and LINUX_SITE from the configuration
ifeq ($(LINUX_VERSION),custom)
LINUX_TARBALL = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION))
LINUX_SITE = $(patsubst %/,%,$(dir $(LINUX_TARBALL)))
LINUX_SOURCE = $(notdir $(LINUX_TARBALL))
else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_GIT),y)
LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL))
LINUX_SITE_METHOD = git
else
LINUX_SOURCE = linux-$(LINUX_VERSION).tar.xz
# In X.Y.Z, get X and Y. We replace dots and dashes by spaces in order
# to use the $(word) function. We support versions such as 3.1,
# 2.6.32, 2.6.32-rc1, 3.0-rc6, etc.
ifeq ($(findstring x2.6.,x$(LINUX_VERSION)),x2.6.)
LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v2.6/
else
LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v3.x/
endif
# release candidates are in testing/ subdir
ifneq ($(findstring -rc,$(LINUX_VERSION)),)
LINUX_SITE := $(LINUX_SITE)testing/
endif # -rc
endif
LINUX_PATCHES = $(call qstrip,$(BR2_LINUX_KERNEL_PATCH))
LINUX_INSTALL_IMAGES = YES
LINUX_DEPENDENCIES += host-module-init-tools host-lzop
ifeq ($(BR2_LINUX_KERNEL_UBOOT_IMAGE),y)
LINUX_DEPENDENCIES += host-uboot-tools
endif
LINUX_MAKE_FLAGS = \
HOSTCC="$(HOSTCC)" \
HOSTCFLAGS="$(HOSTCFLAGS)" \
ARCH=$(KERNEL_ARCH) \
INSTALL_MOD_PATH=$(TARGET_DIR) \
CROSS_COMPILE="$(CCACHE) $(TARGET_CROSS)" \
DEPMOD=$(HOST_DIR)/usr/sbin/depmod
# Get the real Linux version, which tells us where kernel modules are
# going to be installed in the target filesystem.
LINUX_VERSION_PROBED = $(shell $(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) --no-print-directory -s kernelrelease)
ifeq ($(BR2_LINUX_KERNEL_USE_INTREE_DTS),y)
KERNEL_DTS_NAME = $(call qstrip,$(BR2_LINUX_KERNEL_INTREE_DTS_NAME))
else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),y)
KERNEL_DTS_NAME = $(basename $(notdir $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH))))
endif
ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT)$(KERNEL_DTS_NAME),y)
$(error No kernel device tree source specified, check your \
BR2_LINUX_KERNEL_USE_INTREE_DTS / BR2_LINUX_KERNEL_USE_CUSTOM_DTS settings)
endif
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
ifneq ($(words $(KERNEL_DTS_NAME)),1)
$(error Kernel with appended device tree needs exactly one DTS source.\
Check BR2_LINUX_KERNEL_INTREE_DTS_NAME or BR2_LINUX_KERNEL_CUSTOM_DTS_PATH.)
endif
endif
KERNEL_DTBS = $(addsuffix .dtb,$(KERNEL_DTS_NAME))
ifeq ($(BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM),y)
LINUX_IMAGE_NAME=$(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_TARGET_NAME))
else
ifeq ($(BR2_LINUX_KERNEL_UIMAGE),y)
LINUX_IMAGE_NAME=uImage
else ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
LINUX_IMAGE_NAME=uImage
else ifeq ($(BR2_LINUX_KERNEL_BZIMAGE),y)
LINUX_IMAGE_NAME=bzImage
else ifeq ($(BR2_LINUX_KERNEL_ZIMAGE),y)
LINUX_IMAGE_NAME=zImage
else ifeq ($(BR2_LINUX_KERNEL_APPENDED_ZIMAGE),y)
LINUX_IMAGE_NAME=zImage
else ifeq ($(BR2_LINUX_KERNEL_CUIMAGE),y)
LINUX_IMAGE_NAME=cuImage.$(KERNEL_DTS_NAME)
else ifeq ($(BR2_LINUX_KERNEL_SIMPLEIMAGE),y)
LINUX_IMAGE_NAME=simpleImage.$(KERNEL_DTS_NAME)
else ifeq ($(BR2_LINUX_KERNEL_LINUX_BIN),y)
LINUX_IMAGE_NAME=linux.bin
else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
LINUX_IMAGE_NAME=vmlinux.bin
else ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
LINUX_IMAGE_NAME=vmlinux
else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ),y)
LINUX_IMAGE_NAME=vmlinuz
endif
endif
LINUX_KERNEL_UIMAGE_LOADADDR=$(call qstrip,$(BR2_LINUX_KERNEL_UIMAGE_LOADADDR))
ifneq ($(LINUX_KERNEL_UIMAGE_LOADADDR),)
LINUX_MAKE_FLAGS+=LOADADDR="$(LINUX_KERNEL_UIMAGE_LOADADDR)"
endif
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
LINUX_IMAGE_TARGET=zImage
else
LINUX_IMAGE_TARGET=$(LINUX_IMAGE_NAME)
endif
# Compute the arch path, since i386 and x86_64 are in arch/x86 and not
# in arch/$(KERNEL_ARCH). Even if the kernel creates symbolic links
# for bzImage, arch/i386 and arch/x86_64 do not exist when copying the
# defconfig file.
ifeq ($(KERNEL_ARCH),i386)
KERNEL_ARCH_PATH=$(LINUX_DIR)/arch/x86
else ifeq ($(KERNEL_ARCH),x86_64)
KERNEL_ARCH_PATH=$(LINUX_DIR)/arch/x86
else
KERNEL_ARCH_PATH=$(LINUX_DIR)/arch/$(KERNEL_ARCH)
endif
ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
LINUX_IMAGE_PATH=$(LINUX_DIR)/$(LINUX_IMAGE_NAME)
else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ),y)
LINUX_IMAGE_PATH=$(LINUX_DIR)/$(LINUX_IMAGE_NAME)
else
ifeq ($(KERNEL_ARCH),avr32)
LINUX_IMAGE_PATH=$(KERNEL_ARCH_PATH)/boot/images/$(LINUX_IMAGE_NAME)
else
LINUX_IMAGE_PATH=$(KERNEL_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME)
endif
endif # BR2_LINUX_KERNEL_VMLINUX
define LINUX_DOWNLOAD_PATCHES
$(if $(LINUX_PATCHES),
@$(call MESSAGE,"Download additional patches"))
$(foreach patch,$(filter ftp://% http://%,$(LINUX_PATCHES)),\
$(call DOWNLOAD,$(patch))$(sep))
endef
LINUX_POST_DOWNLOAD_HOOKS += LINUX_DOWNLOAD_PATCHES
define LINUX_APPLY_PATCHES
for p in $(LINUX_PATCHES) ; do \
if echo $$p | grep -q -E "^ftp://|^http://" ; then \
support/scripts/apply-patches.sh $(@D) $(DL_DIR) `basename $$p` ; \
elif test -d $$p ; then \
support/scripts/apply-patches.sh $(@D) $$p linux-\*.patch ; \
else \
support/scripts/apply-patches.sh $(@D) `dirname $$p` `basename $$p` ; \
fi \
done
endef
LINUX_POST_PATCH_HOOKS += LINUX_APPLY_PATCHES
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
KERNEL_SOURCE_CONFIG = $(KERNEL_ARCH_PATH)/configs/$(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG))_defconfig
else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
KERNEL_SOURCE_CONFIG = $(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE)
endif
define LINUX_CONFIGURE_CMDS
cp $(KERNEL_SOURCE_CONFIG) $(KERNEL_ARCH_PATH)/configs/buildroot_defconfig
$(TARGET_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) buildroot_defconfig
rm $(KERNEL_ARCH_PATH)/configs/buildroot_defconfig
$(if $(BR2_arm)$(BR2_armeb),
$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI,$(@D)/.config))
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
# As the kernel gets compiled before root filesystems are
# built, we create a fake cpio file. It'll be
# replaced later by the real cpio archive, and the kernel will be
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
# rebuilt using the linux26-rebuild-with-initramfs target.
$(if $(BR2_TARGET_ROOTFS_INITRAMFS),
touch $(BINARIES_DIR)/rootfs.cpio
$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD,$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,\"$(BINARIES_DIR)/rootfs.cpio\",$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0,$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0,$(@D)/.config))
$(if $(BR2_ROOTFS_DEVICE_CREATION_STATIC),,
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS,$(@D)/.config)
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT,$(@D)/.config))
$(if $(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),
$(call KCONFIG_SET_OPT,CONFIG_UEVENT_HELPER_PATH,\"/sbin/mdev\",$(@D)/.config))
$(if $(BR2_PACKAGE_SYSTEMD),
$(call KCONFIG_ENABLE_OPT,CONFIG_CGROUPS,$(@D)/.config))
$(if $(BR2_LINUX_KERNEL_APPENDED_DTB),
$(call KCONFIG_ENABLE_OPT,CONFIG_ARM_APPENDED_DTB,$(@D)/.config))
yes '' | $(TARGET_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) oldconfig
endef
ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)
ifeq ($(BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT),)
define LINUX_BUILD_DTB
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(KERNEL_DTBS)
endef
define LINUX_INSTALL_DTB
# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
cp $(addprefix \
$(KERNEL_ARCH_PATH)/boot/$(if $(wildcard \
$(addprefix $(KERNEL_ARCH_PATH)/boot/dts/,$(KERNEL_DTBS))),dts/),$(KERNEL_DTBS)) \
$(BINARIES_DIR)/
endef
define LINUX_INSTALL_DTB_TARGET
# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
cp $(addprefix \
$(KERNEL_ARCH_PATH)/boot/$(if $(wildcard \
$(addprefix $(KERNEL_ARCH_PATH)/boot/dts/,$(KERNEL_DTBS))),dts/),$(KERNEL_DTBS)) \
$(TARGET_DIR)/boot/
endef
endif
endif
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
# dtbs moved from arch/$ARCH/boot to arch/$ARCH/boot/dts since 3.8-rc1
define LINUX_APPEND_DTB
if [ -e $(KERNEL_ARCH_PATH)/boot/$(KERNEL_DTS_NAME).dtb ]; then \
cat $(KERNEL_ARCH_PATH)/boot/$(KERNEL_DTS_NAME).dtb; \
else \
cat $(KERNEL_ARCH_PATH)/boot/dts/$(KERNEL_DTS_NAME).dtb; \
fi >> $(KERNEL_ARCH_PATH)/boot/zImage
endef
ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
# We need to generate the uImage here after that so that the uImage is
# generated with the right image size.
LINUX_APPEND_DTB += $(sep)$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) uImage
endif
endif
# Compilation. We make sure the kernel gets rebuilt when the
# configuration has changed.
define LINUX_BUILD_CMDS
$(if $(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),
cp $(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH) $(KERNEL_ARCH_PATH)/boot/dts/)
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_IMAGE_TARGET)
@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then \
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) modules ; \
fi
$(LINUX_BUILD_DTB)
$(LINUX_APPEND_DTB)
endef
ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET
install -m 0644 -D $(LINUX_IMAGE_PATH) $(TARGET_DIR)/boot/$(LINUX_IMAGE_NAME)
$(LINUX_INSTALL_DTB_TARGET)
endef
endif
define LINUX_INSTALL_HOST_TOOLS
# Installing dtc (device tree compiler) as host tool, if selected
if grep -q "CONFIG_DTC=y" $(@D)/.config; then \
$(INSTALL) -D -m 0755 $(@D)/scripts/dtc/dtc $(HOST_DIR)/usr/bin/dtc ; \
fi
endef
define LINUX_INSTALL_IMAGES_CMDS
cp $(LINUX_IMAGE_PATH) $(BINARIES_DIR)
endef
define LINUX_INSTALL_TARGET_CMDS
$(LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET)
$(LINUX_INSTALL_DTB)
# Install modules and remove symbolic links pointing to build
# directories, not relevant on the target
@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then \
$(TARGET_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) \
DEPMOD="$(HOST_DIR)/usr/sbin/depmod" modules_install ; \
rm -f $(TARGET_DIR)/lib/modules/$(LINUX_VERSION_PROBED)/build ; \
rm -f $(TARGET_DIR)/lib/modules/$(LINUX_VERSION_PROBED)/source ; \
fi
$(LINUX_INSTALL_HOST_TOOLS)
endef
include linux/linux-ext-*.mk
$(eval $(generic-package))
ifeq ($(BR2_LINUX_KERNEL),y)
linux-menuconfig linux-xconfig linux-gconfig linux-nconfig linux26-menuconfig linux26-xconfig linux26-gconfig linux26-nconfig: dirs linux-configure
$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) \
$(subst linux-,,$(subst linux26-,,$@))
rm -f $(LINUX_DIR)/.stamp_{built,target_installed,images_installed}
linux-savedefconfig linux26-savedefconfig: dirs linux-configure
$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) \
$(subst linux-,,$(subst linux26-,,$@))
ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
linux-update-config linux26-update-config: linux-configure $(LINUX_DIR)/.config
cp -f $(LINUX_DIR)/.config $(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE)
linux-update-defconfig linux26-update-defconfig: linux-savedefconfig
cp -f $(LINUX_DIR)/defconfig $(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE)
else
linux-update-config linux26-update-config: ;
linux-update-defconfig linux26-update-defconfig: ;
endif
endif
# Support for rebuilding the kernel after the cpio archive has
# been generated in $(BINARIES_DIR)/rootfs.cpio.
$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(LINUX_DIR)/.stamp_target_installed $(LINUX_DIR)/.stamp_images_installed $(BINARIES_DIR)/rootfs.cpio
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
@$(call MESSAGE,"Rebuilding kernel with initramfs")
# Build the kernel.
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_IMAGE_NAME)
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
# Copy the kernel image to its final destination
cp $(LINUX_IMAGE_PATH) $(BINARIES_DIR)
# If there is a .ub file copy it to the final destination
test ! -f $(LINUX_IMAGE_PATH).ub || cp $(LINUX_IMAGE_PATH).ub $(BINARIES_DIR)
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
$(Q)touch $@
# The initramfs building code must make sure this target gets called
# after it generated the initramfs list of files.
linux-rebuild-with-initramfs linux26-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_initramfs_rebuilt
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the fs/common.mk infrastructure. This allows individual filesystems to set a target name that we should depend on *after* generating the root filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
# Checks to give errors that the user can understand
ifeq ($(filter source,$(MAKECMDGOALS)),)
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG)),)
$(error No kernel defconfig name specified, check your BR2_LINUX_KERNEL_DEFCONFIG setting)
endif
endif
ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE)),)
$(error No kernel configuration file specified, check your BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE setting)
endif
endif
endif