buildroot/linux/linux.mk

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###############################################################################
#
# Linux kernel 2.6 target
#
###############################################################################
LINUX26_VERSION=$(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
# Compute LINUX26_SOURCE and LINUX26_SITE from the configuration
ifeq ($(LINUX26_VERSION),custom)
LINUX26_TARBALL:=$(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION))
LINUX26_SITE:=$(dir $(LINUX26_TARBALL))
LINUX26_SOURCE:=$(notdir $(LINUX26_TARBALL))
else
LINUX26_SOURCE:=linux-$(LINUX26_VERSION).tar.bz2
LINUX26_SITE:=$(BR2_KERNEL_MIRROR)/linux/kernel/v2.6/
endif
LINUX26_DIR:=$(BUILD_DIR)/linux-$(LINUX26_VERSION)
LINUX26_PATCH=$(call qstrip,$(BR2_LINUX_KERNEL_PATCH))
LINUX26_MAKE_FLAGS = \
HOSTCC="$(HOSTCC)" \
HOSTCFLAGS="$(HOSTCFLAGS)" \
ARCH=$(KERNEL_ARCH) \
INSTALL_MOD_PATH=$(TARGET_DIR) \
CROSS_COMPILE="$(CCACHE) $(TARGET_CROSS)" \
LZMA="$(LZMA)"
# Get the real Linux version, which tells us where kernel modules are
# going to be installed in the target filesystem.
LINUX26_VERSION_PROBED = $(shell $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(LINUX26_DIR) --no-print-directory -s kernelrelease)
ifeq ($(BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM),y)
LINUX26_IMAGE_NAME=$(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_TARGET_NAME))
else
ifeq ($(BR2_LINUX_KERNEL_UIMAGE),y)
ifeq ($(KERNEL_ARCH),blackfin)
# a uImage, but with a different file name
LINUX26_IMAGE_NAME=vmImage
else
LINUX26_IMAGE_NAME=uImage
endif
LINUX26_DEPENDENCIES+=$(MKIMAGE)
else ifeq ($(BR2_LINUX_KERNEL_BZIMAGE),y)
LINUX26_IMAGE_NAME=bzImage
else ifeq ($(BR2_LINUX_KERNEL_ZIMAGE),y)
LINUX26_IMAGE_NAME=zImage
else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
LINUX26_IMAGE_NAME=vmlinux.bin
else ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
LINUX26_IMAGE_NAME=vmlinux
endif
endif
# Compute the arch path, since i386 and x86_64 are in arch/x86 and not
# in arch/$(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 ($(KERNEL_ARCH),i386)
KERNEL_ARCH_PATH=$(LINUX26_DIR)/arch/x86
else ifeq ($(KERNEL_ARCH),x86_64)
KERNEL_ARCH_PATH=$(LINUX26_DIR)/arch/x86
else
KERNEL_ARCH_PATH=$(LINUX26_DIR)/arch/$(KERNEL_ARCH)
endif
ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
LINUX26_IMAGE_PATH=$(LINUX26_DIR)/$(LINUX26_IMAGE_NAME)
else
ifeq ($(KERNEL_ARCH),avr32)
LINUX26_IMAGE_PATH=$(KERNEL_ARCH_PATH)/boot/images/$(LINUX26_IMAGE_NAME)
else
LINUX26_IMAGE_PATH=$(KERNEL_ARCH_PATH)/boot/$(LINUX26_IMAGE_NAME)
endif
endif # BR2_LINUX_KERNEL_VMLINUX
# Download
$(LINUX26_DIR)/.stamp_downloaded:
@$(call MESSAGE,"Downloading kernel")
$(call DOWNLOAD,$(LINUX26_SITE),$(LINUX26_SOURCE))
$(foreach patch,$(filter ftp://% http://%,$(LINUX26_PATCH)),\
$(call DOWNLOAD,$(dir $(patch)),$(notdir $(patch)))$(sep))
mkdir -p $(@D)
touch $@
# Extraction
$(LINUX26_DIR)/.stamp_extracted: $(LINUX26_DIR)/.stamp_downloaded
@$(call MESSAGE,"Extracting kernel")
mkdir -p $(@D)
$(Q)$(INFLATE$(suffix $(LINUX26_SOURCE))) $(DL_DIR)/$(LINUX26_SOURCE) | \
tar -C $(@D) $(TAR_STRIP_COMPONENTS)=1 $(TAR_OPTIONS) -
$(Q)touch $@
# Patch
$(LINUX26_DIR)/.stamp_patched: $(LINUX26_DIR)/.stamp_extracted
@$(call MESSAGE,"Patching kernel")
for p in $(LINUX26_PATCH) ; do \
if echo $$p | grep -q -E "^ftp://|^http://" ; then \
toolchain/patch-kernel.sh $(@D) $(DL_DIR) `basename $$p` ; \
elif test -d $$p ; then \
toolchain/patch-kernel.sh $(@D) $$p linux-\*.patch ; \
else \
toolchain/patch-kernel.sh $(@D) `dirname $$p` `basename $$p` ; \
fi \
done
$(Q)touch $@
# Configuration
$(LINUX26_DIR)/.stamp_configured: $(LINUX26_DIR)/.stamp_patched
@$(call MESSAGE,"Configuring kernel")
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
$(TARGET_MAKE_ENV) $(MAKE1) $(LINUX26_MAKE_FLAGS) -C $(@D) $(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG))_defconfig
else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
cp $(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE) $(KERNEL_ARCH_PATH)/configs/buildroot_defconfig
$(TARGET_MAKE_ENV) $(MAKE1) $(LINUX26_MAKE_FLAGS) -C $(@D) buildroot_defconfig
rm $(KERNEL_ARCH_PATH)/configs/buildroot_defconfig
endif
ifeq ($(BR2_ARM_EABI),y)
$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI,$(@D)/.config)
else
$(call KCONFIG_DISABLE_OPT,CONFIG_AEABI,$(@D)/.config)
endif
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
ifeq ($(BR2_TARGET_ROOTFS_INITRAMFS),y)
# As the kernel gets compiled before root filesystems are
# built, we create a fake initramfs file list. It'll be
# replaced later by the real list, and the kernel will be
# rebuilt using the linux26-rebuild-with-initramfs target.
touch $(BINARIES_DIR)/rootfs.initramfs
$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD,$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,\"$(BINARIES_DIR)/rootfs.initramfs\",$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0,$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0,$(@D)/.config)
$(call KCONFIG_DISABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_NONE,$(@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
$(call KCONFIG_ENABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_GZIP,$(@D)/.config)
endif
ifneq ($(BR2_ROOTFS_DEVICE_CREATION_STATIC),y)
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS,$(@D)/.config)
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT,$(@D)/.config)
endif
ifeq ($(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),y)
$(call KCONFIG_SET_OPT,CONFIG_UEVENT_HELPER_PATH,\"/sbin/mdev\",$(@D)/.config)
endif
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(@D) oldconfig
$(Q)touch $@
# Compilation. We make sure the kernel gets rebuilt when the
# configuration has changed.
$(LINUX26_DIR)/.stamp_compiled: $(LINUX26_DIR)/.stamp_configured $(LINUX26_DIR)/.config
@$(call MESSAGE,"Compiling kernel")
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(@D) $(LINUX26_IMAGE_NAME)
@if [ $(shell grep -c "CONFIG_MODULES=y" $(LINUX26_DIR)/.config) != 0 ] ; then \
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(@D) modules ; \
fi
$(Q)touch $@
# Installation
$(LINUX26_DIR)/.stamp_installed: $(LINUX26_DIR)/.stamp_compiled
@$(call MESSAGE,"Installing kernel")
ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
install -m 0644 -D $(LINUX26_IMAGE_PATH) $(TARGET_DIR)/boot/$(LINUX26_IMAGE_NAME)
endif
cp $(LINUX26_IMAGE_PATH) $(BINARIES_DIR)
# Install modules and remove symbolic links pointing to build
# directories, not relevant on the target
@if [ $(shell grep -c "CONFIG_MODULES=y" $(LINUX26_DIR)/.config) != 0 ] ; then \
$(TARGET_MAKE_ENV) $(MAKE1) $(LINUX26_MAKE_FLAGS) -C $(@D) \
DEPMOD="$(HOST_DIR)/usr/sbin/depmod" modules_install ; \
rm -f $(TARGET_DIR)/lib/modules/$(LINUX26_VERSION_PROBED)/build ; \
rm -f $(TARGET_DIR)/lib/modules/$(LINUX26_VERSION_PROBED)/source ; \
fi
$(Q)touch $@
linux linux26: host-module-init-tools $(LINUX26_DEPENDENCIES) $(LINUX26_DIR)/.stamp_installed
linux-menuconfig linux-xconfig linux-gconfig linux-nconfig linux26-menuconfig linux26-xconfig linux26-gconfig linux26-nconfig: dirs $(LINUX26_DIR)/.stamp_configured
$(MAKE) $(LINUX26_MAKE_FLAGS) -C $(LINUX26_DIR) \
$(subst linux-,,$(subst linux26-,,$@))
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(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
# Support for rebuilding the kernel after the initramfs file list has
# been generated in $(BINARIES_DIR)/rootfs.initramfs.
$(LINUX26_DIR)/.stamp_initramfs_rebuilt: $(LINUX26_DIR)/.stamp_installed $(BINARIES_DIR)/rootfs.initramfs
@$(call MESSAGE,"Rebuilding kernel with initramfs")
# Remove the previously generated initramfs which was empty,
# to make sure the kernel will actually regenerate it.
$(RM) -f $(@D)/usr/initramfs_data.cpio*
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(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
# Build the kernel.
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(@D) $(LINUX26_IMAGE_NAME)
# Copy the kernel image to its final destination
cp $(LINUX26_IMAGE_PATH) $(BINARIES_DIR)
$(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: $(LINUX26_DIR)/.stamp_initramfs_rebuilt
linux: add support for initramfs In Buildroot, the kernel is built and installed *before* the root filesystems are built. This allows the root filesystem to correctly contain the kernel modules that have been installed. However, in the initramfs case, the root filesystem is part of the kernel. Therefore, the kernel should be built *after* the root filesystem (which, in the initramfs case simply builds a text file listing all files/directories/devices/symlinks that should be part of the initramfs). However, this isn't possible as the initramfs text file would lack all kernel modules. So, the solution choosen here is to keep the normal order: kernel is built before the root filesystem is generated, and to add a little quirk to retrigger a kernel compilation after the root filesystem generation. To do so, we add a ROOTFS_$(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_$(FSTYPE)_DEPENDENCIES, on which we depend *before* generating the root filesystem). The initramfs code in fs/initramfs/initramfs.mk uses this to add a dependency on 'linux26-rebuild-with-initramfs'. In linux/linux.mk, we do various things : * If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is enabled as a root filesystem type), then we create an empty rootfs.initramfs file (remember that at this point, the root filesystem hasn't been generated) and we adjust the kernel configuration to include an initramfs. Of course, in the initial kernel build, this initramfs will be empty. * In the linux26-rebuild-with-initramfs target, we retrigger a compilation of the kernel image, after removing the initramfs in the kernel sources to make sure it gets properly rebuilt (we've experienced cases were modifying the rootfs.initramfs file wouldn't retrigger the generation of the initramfs at the kernel level). This is fairly quirky, but initramfs really is a special case, so in one way or another, we need a little quirk to solve its specialness. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2010-06-14 01:19:38 +08:00
ifeq ($(BR2_LINUX_KERNEL),y)
TARGETS+=linux26
endif
# 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