buildroot/linux/linux.mk
Yann E. MORIN 40e0bf4c0c linux: forcibly disable use of gcc plugins
The soon-to-be-released linux 5.7 has changed the way it detects the
ability of gcc to use plugins, when it dropped support for gcc 4.7 or
older [0].

To detect the ability to use gcc plugins, the kernel has to check
whether the host gcc is capable enough to build them.

When we call one of the configurator for the Linux kernel, we explicitly
pass a value of HOSTCC=$(HOSTCC_NOCCACHE), because there might be a
discrepancy between the ncurses headers and libraries as found by the
Linux kconfig build [1] [2].

But then, when we build the kernel, we pass another value to use [3]
HOSTCC="$(HOSTCC) $(HOST_CFLAGS) $(HOST_LDFLAGS)" which boils down to
roughly: gcc -I.../host/include -L.../host/lib -Wl,-rpath,.../host/lib
This is needed so that at build time, the kernel can build host tools
that link with our openssl et al.

So, the two HOSTCC we pass to the kernel may have different behaviours.
For example, on a machine where gmp is missing in the system, it is
available in $(O)/host/ when using an internal toolchain (and under a
few other conditions).

In that case, when configuring the kernel, it decides that the host
compiler can't build plugins, so the dependencies of CONFIG_GCC_PLUGINS
are not met, and that option is not present in the linux' .config file
(neither as "=y" nor as "is not set"). But then, when we build the
kernel, the host compiler suddenly becomes capable of building the
plugins, and the internal syncconfig run by the kernel will notice that
the dependencies of CONFIG_GCC_PLUGINS are now met, and that the user
shall decide on its value. And this blocks a build on an interactive
console (abbreviated):

    * Restart config...
    * GCC plugins
    GCC plugins (GCC_PLUGINS) [Y/n/?] (NEW) _

But most problematic is the behaviour when run in a shell that is not
interactiove (e.g. a CI job or such) (abbreviated):

    * Restart config...
    * GCC plugins
    GCC plugins (GCC_PLUGINS) [Y/n/?] (NEW)
    Error in reading or end of file.
      Generate some entropy during boot and runtime (GCC_PLUGIN_LATENT_ENTROPY) [N/y/?] (NEW)
    Error in reading or end of file.
      Randomize layout of sensitive kernel structures (GCC_PLUGIN_RANDSTRUCT) [N/y/?] (NEW)
    Error in reading or end of file.
    * Memory initialization
    Initialize kernel stack variables at function entry
    > 1. no automatic initialization (weakest) (INIT_STACK_NONE)
      2. zero-init structs marked for userspace (weak) (GCC_PLUGIN_STRUCTLEAK_USER) (NEW)
      3. zero-init structs passed by reference (strong) (GCC_PLUGIN_STRUCTLEAK_BYREF) (NEW)
      4. zero-init anything passed by reference (very strong) (GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) (NEW)
    choice[1-4?]:
    Error in reading or end of file.
    Poison kernel stack before returning from syscalls (GCC_PLUGIN_STACKLEAK) [N/y/?] (NEW)
    Error in reading or end of file.
    Enable heap memory zeroing on allocation by default (INIT_ON_ALLOC_DEFAULT_ON) [N/y/?] n
    Enable heap memory zeroing on free by default (INIT_ON_FREE_DEFAULT_ON) [N/y/?] n

The most obvious and simple solution would be to unconditionally disable
gcc plugins altogether, in the KCONFIG_FIXUP hook. But that can't work
either, because after applying the fixups, we call olddefconfig (or the
likes) with the incapable HOSTCC, so the disabled option would be removed
anyway, and we'd be back to square one.

So, in addition to the above, we also forcibly hack the same call just
before actually building the kernel.

Note that the two are needed: the one in the fixups is needed for those
that have a system that already allows building gcc plugins, and the
second is needed in the other case, where the system does not allow it
but would work with our additional headers and libs in $(O)/host/. The
two ensure there is a very similar experience in the two situations.

Forcibly disabling the use of gcc plugins is not a regression on our
side: it has never been possible to do so so far. We're now making sure
that can't work by accident.

Reported-by: Ganesh <ganesh45in@gmail.com>,
Reported-by: Heiko Thiery <heiko.thiery@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Michael Walle <michael.walle@kontron.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Tested-by: Heiko Thiery <heiko.thiery@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2020-05-31 22:41:57 +02:00

582 lines
22 KiB
Makefile

################################################################################
#
# Linux kernel target
#
################################################################################
LINUX_VERSION = $(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
LINUX_LICENSE = GPL-2.0
ifeq ($(BR2_LINUX_KERNEL_LATEST_VERSION),y)
LINUX_LICENSE_FILES = \
COPYING \
LICENSES/preferred/GPL-2.0 \
LICENSES/exceptions/Linux-syscall-note
endif
define LINUX_HELP_CMDS
@echo ' linux-menuconfig - Run Linux kernel menuconfig'
@echo ' linux-savedefconfig - Run Linux kernel savedefconfig'
@echo ' linux-update-defconfig - Save the Linux configuration to the path specified'
@echo ' by BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE'
endef
# Compute LINUX_SOURCE and LINUX_SITE from the configuration
ifeq ($(BR2_LINUX_KERNEL_CUSTOM_TARBALL),y)
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_REPO_URL))
LINUX_SITE_METHOD = git
else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_HG),y)
LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
LINUX_SITE_METHOD = hg
else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_SVN),y)
LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
LINUX_SITE_METHOD = svn
else ifeq ($(BR2_LINUX_KERNEL_LATEST_CIP_VERSION)$(BR2_LINUX_KERNEL_LATEST_CIP_RT_VERSION),y)
LINUX_SOURCE = linux-cip-$(LINUX_VERSION).tar.gz
LINUX_SITE = https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/snapshot
else ifneq ($(findstring -rc,$(LINUX_VERSION)),)
# Since 4.12-rc1, -rc kernels are generated from cgit. This also works for
# older -rc kernels.
LINUX_SITE = https://git.kernel.org/torvalds/t
else
LINUX_SOURCE = linux-$(LINUX_VERSION).tar.xz
ifeq ($(findstring x2.6.,x$(LINUX_VERSION)),x2.6.)
LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v2.6
else
LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v$(firstword $(subst ., ,$(LINUX_VERSION))).x
endif
endif
ifeq ($(BR2_LINUX_KERNEL)$(BR2_LINUX_KERNEL_LATEST_VERSION),y)
BR_NO_CHECK_HASH_FOR += $(LINUX_SOURCE)
endif
LINUX_PATCHES = $(call qstrip,$(BR2_LINUX_KERNEL_PATCH))
# We have no way to know the hashes for user-supplied patches.
BR_NO_CHECK_HASH_FOR += $(notdir $(LINUX_PATCHES))
# We rely on the generic package infrastructure to download and apply
# remote patches (downloaded from ftp, http or https). For local
# patches, we can't rely on that infrastructure, because there might
# be directories in the patch list (unlike for other packages).
LINUX_PATCH = $(filter ftp://% http://% https://%,$(LINUX_PATCHES))
# while the kernel is built for the target, the build may need various
# host libraries depending on config (and version), so use
# HOST_MAKE_ENV here. In particular, this ensures that our
# host-pkgconf will look for host libraries and not target ones.
LINUX_MAKE_ENV = \
$(HOST_MAKE_ENV) \
BR_BINARIES_DIR=$(BINARIES_DIR)
LINUX_INSTALL_IMAGES = YES
LINUX_DEPENDENCIES = host-kmod \
$(if $(BR2_PACKAGE_INTEL_MICROCODE),intel-microcode)
# Starting with 4.16, the generated kconfig paser code is no longer
# shipped with the kernel sources, so we need flex and bison, but
# only if the host does not have them.
LINUX_KCONFIG_DEPENDENCIES = \
$(BR2_BISON_HOST_DEPENDENCY) \
$(BR2_FLEX_HOST_DEPENDENCY)
# Starting with 4.18, the kconfig in the kernel calls the
# cross-compiler to check its capabilities. So we need the
# toolchain before we can call the configurators.
LINUX_KCONFIG_DEPENDENCIES += toolchain
# host tools needed for kernel compression
ifeq ($(BR2_LINUX_KERNEL_LZ4),y)
LINUX_DEPENDENCIES += host-lz4
else ifeq ($(BR2_LINUX_KERNEL_LZMA),y)
LINUX_DEPENDENCIES += host-lzma
else ifeq ($(BR2_LINUX_KERNEL_LZO),y)
LINUX_DEPENDENCIES += host-lzop
else ifeq ($(BR2_LINUX_KERNEL_XZ),y)
LINUX_DEPENDENCIES += host-xz
endif
LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_GZIP) += CONFIG_KERNEL_GZIP
LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZ4) += CONFIG_KERNEL_LZ4
LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZMA) += CONFIG_KERNEL_LZMA
LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZO) += CONFIG_KERNEL_LZO
LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_XZ) += CONFIG_KERNEL_XZ
ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL),y)
LINUX_DEPENDENCIES += host-openssl
endif
ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF),y)
LINUX_DEPENDENCIES += host-elfutils host-pkgconf
endif
# If host-uboot-tools is selected by the user, assume it is needed to
# create a custom image
ifeq ($(BR2_PACKAGE_HOST_UBOOT_TOOLS),y)
LINUX_DEPENDENCIES += host-uboot-tools
endif
ifneq ($(ARCH_XTENSA_OVERLAY_FILE),)
define LINUX_XTENSA_OVERLAY_EXTRACT
$(call arch-xtensa-overlay-extract,$(@D),linux)
endef
LINUX_POST_EXTRACT_HOOKS += LINUX_XTENSA_OVERLAY_EXTRACT
LINUX_EXTRA_DOWNLOADS += $(ARCH_XTENSA_OVERLAY_URL)
endif
# We don't want to run depmod after installing the kernel. It's done in a
# target-finalize hook, to encompass modules installed by packages.
LINUX_MAKE_FLAGS = \
HOSTCC="$(HOSTCC) $(HOST_CFLAGS) $(HOST_LDFLAGS)" \
ARCH=$(KERNEL_ARCH) \
INSTALL_MOD_PATH=$(TARGET_DIR) \
CROSS_COMPILE="$(TARGET_CROSS)" \
DEPMOD=$(HOST_DIR)/sbin/depmod
ifeq ($(BR2_REPRODUCIBLE),y)
LINUX_MAKE_ENV += \
KBUILD_BUILD_VERSION=1 \
KBUILD_BUILD_USER=buildroot \
KBUILD_BUILD_HOST=buildroot \
KBUILD_BUILD_TIMESTAMP="$(shell LC_ALL=C date -d @$(SOURCE_DATE_EPOCH))"
endif
# gcc-8 started warning about function aliases that have a
# non-matching prototype. This seems rather useful in general, but it
# causes tons of warnings in the Linux kernel, where we rely on
# abusing those aliases for system call entry points, in order to
# sanitize the arguments passed from user space in registers.
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82435
ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_8),y)
LINUX_MAKE_ENV += KCFLAGS=-Wno-attribute-alias
endif
ifeq ($(BR2_LINUX_KERNEL_DTB_OVERLAY_SUPPORT),y)
LINUX_MAKE_ENV += DTC_FLAGS=-@
endif
# Get the real Linux version, which tells us where kernel modules are
# going to be installed in the target filesystem.
LINUX_VERSION_PROBED = `$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) --no-print-directory -s kernelrelease 2>/dev/null`
LINUX_DTS_NAME += $(call qstrip,$(BR2_LINUX_KERNEL_INTREE_DTS_NAME))
# We keep only the .dts files, so that the user can specify both .dts
# and .dtsi files in BR2_LINUX_KERNEL_CUSTOM_DTS_PATH. Both will be
# copied to arch/<arch>/boot/dts, but only the .dts files will
# actually be generated as .dtb.
LINUX_DTS_NAME += $(basename $(filter %.dts,$(notdir $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)))))
LINUX_DTBS = $(addsuffix .dtb,$(LINUX_DTS_NAME))
ifeq ($(BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM),y)
LINUX_IMAGE_NAME = $(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_NAME))
LINUX_TARGET_NAME = $(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_TARGET_NAME))
ifeq ($(LINUX_IMAGE_NAME),)
LINUX_IMAGE_NAME = $(LINUX_TARGET_NAME)
endif
else
ifeq ($(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_ZIMAGE_EPAPR),y)
LINUX_IMAGE_NAME = zImage.epapr
else ifeq ($(BR2_LINUX_KERNEL_APPENDED_ZIMAGE),y)
LINUX_IMAGE_NAME = zImage
else ifeq ($(BR2_LINUX_KERNEL_CUIMAGE),y)
LINUX_IMAGE_NAME = cuImage.$(firstword $(LINUX_DTS_NAME))
else ifeq ($(BR2_LINUX_KERNEL_SIMPLEIMAGE),y)
LINUX_IMAGE_NAME = simpleImage.$(firstword $(LINUX_DTS_NAME))
else ifeq ($(BR2_LINUX_KERNEL_IMAGE),y)
LINUX_IMAGE_NAME = Image
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
else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ_BIN),y)
LINUX_IMAGE_NAME = vmlinuz.bin
endif
# The if-else blocks above are all the image types we know of, and all
# come from a Kconfig choice, so we know we have LINUX_IMAGE_NAME set
# to something
LINUX_TARGET_NAME = $(LINUX_IMAGE_NAME)
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
# 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)
LINUX_ARCH_PATH = $(LINUX_DIR)/arch/x86
else ifeq ($(KERNEL_ARCH),x86_64)
LINUX_ARCH_PATH = $(LINUX_DIR)/arch/x86
else
LINUX_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 ($(BR2_LINUX_KERNEL_VMLINUZ_BIN),y)
LINUX_IMAGE_PATH = $(LINUX_DIR)/$(LINUX_IMAGE_NAME)
else
LINUX_IMAGE_PATH = $(LINUX_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME)
endif # BR2_LINUX_KERNEL_VMLINUX
define LINUX_APPLY_LOCAL_PATCHES
for p in $(filter-out ftp://% http://% https://%,$(LINUX_PATCHES)) ; do \
if test -d $$p ; then \
$(APPLY_PATCHES) $(@D) $$p \*.patch || exit 1 ; \
else \
$(APPLY_PATCHES) $(@D) `dirname $$p` `basename $$p` || exit 1; \
fi \
done
endef
LINUX_POST_PATCH_HOOKS += LINUX_APPLY_LOCAL_PATCHES
# Older linux kernels use deprecated perl constructs in timeconst.pl
# that were removed for perl 5.22+ so it breaks on newer distributions
# Try a dry-run patch to see if this applies, if it does go ahead
define LINUX_TRY_PATCH_TIMECONST
@if patch -p1 --dry-run -f -s -d $(@D) <$(LINUX_PKGDIR)/0001-timeconst.pl-Eliminate-Perl-warning.patch.conditional >/dev/null ; then \
$(APPLY_PATCHES) $(@D) $(LINUX_PKGDIR) 0001-timeconst.pl-Eliminate-Perl-warning.patch.conditional ; \
fi
endef
LINUX_POST_PATCH_HOOKS += LINUX_TRY_PATCH_TIMECONST
LINUX_KERNEL_CUSTOM_LOGO_PATH = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_LOGO_PATH))
ifneq ($(LINUX_KERNEL_CUSTOM_LOGO_PATH),)
LINUX_DEPENDENCIES += host-imagemagick
define LINUX_KERNEL_CUSTOM_LOGO_CONVERT
$(HOST_DIR)/bin/convert $(LINUX_KERNEL_CUSTOM_LOGO_PATH) \
-dither None -colors 224 -compress none \
$(LINUX_DIR)/drivers/video/logo/logo_linux_clut224.ppm
endef
LINUX_PRE_BUILD_HOOKS += LINUX_KERNEL_CUSTOM_LOGO_CONVERT
endif
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
LINUX_KCONFIG_DEFCONFIG = $(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG))_defconfig
else ifeq ($(BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG),y)
LINUX_KCONFIG_DEFCONFIG = defconfig
else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
LINUX_KCONFIG_FILE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE))
endif
LINUX_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES))
LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
# LINUX_MAKE_FLAGS overrides HOSTCC to allow the kernel build to find
# our host-openssl and host-libelf. However, this triggers a bug in
# the kconfig build script that causes it to build with
# /usr/include/ncurses.h (which is typically wchar) but link with
# $(HOST_DIR)/lib/libncurses.so (which is not). We don't actually
# need any host-package for kconfig, so remove the HOSTCC override
# again. In addition, even though linux depends on the toolchain and
# therefore host-ccache would be ready, we use HOSTCC_NOCCACHE for
# consistency with other kconfig packages.
LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS) HOSTCC="$(HOSTCC_NOCCACHE)"
# If no package has yet set it, set it from the Kconfig option
LINUX_NEEDS_MODULES ?= $(BR2_LINUX_NEEDS_MODULES)
# Make sure the Linux kernel is built with the right endianness. Not
# all architectures support
# CONFIG_CPU_BIG_ENDIAN/CONFIG_CPU_LITTLE_ENDIAN in Linux, but the
# option will be thrown away and ignored if it doesn't exist.
ifeq ($(BR2_ENDIAN),"BIG")
define LINUX_FIXUP_CONFIG_ENDIANNESS
$(call KCONFIG_ENABLE_OPT,CONFIG_CPU_BIG_ENDIAN)
endef
else
define LINUX_FIXUP_CONFIG_ENDIANNESS
$(call KCONFIG_ENABLE_OPT,CONFIG_CPU_LITTLE_ENDIAN)
endef
endif
define LINUX_KCONFIG_FIXUP_CMDS
$(if $(LINUX_NEEDS_MODULES),
$(call KCONFIG_ENABLE_OPT,CONFIG_MODULES))
$(call KCONFIG_ENABLE_OPT,$(strip $(LINUX_COMPRESSION_OPT_y)))
$(foreach opt, $(LINUX_COMPRESSION_OPT_),
$(call KCONFIG_DISABLE_OPT,$(opt))
)
$(LINUX_FIXUP_CONFIG_ENDIANNESS)
$(if $(BR2_arm)$(BR2_armeb),
$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI))
$(if $(BR2_powerpc)$(BR2_powerpc64)$(BR2_powerpc64le),
$(call KCONFIG_ENABLE_OPT,CONFIG_PPC_DISABLE_WERROR))
$(if $(BR2_ARC_PAGE_SIZE_4K),
$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
$(if $(BR2_ARC_PAGE_SIZE_8K),
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
$(if $(BR2_ARC_PAGE_SIZE_16K),
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
$(if $(BR2_TARGET_ROOTFS_CPIO),
$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD))
# 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
# rebuilt using the linux-rebuild-with-initramfs target.
$(if $(BR2_TARGET_ROOTFS_INITRAMFS),
mkdir -p $(BINARIES_DIR)
touch $(BINARIES_DIR)/rootfs.cpio
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,"$${BR_BINARIES_DIR}/rootfs.cpio")
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0))
$(if $(BR2_ROOTFS_DEVICE_CREATION_STATIC),,
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS)
$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT))
$(if $(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV),
$(call KCONFIG_ENABLE_OPT,CONFIG_INOTIFY_USER))
$(if $(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),
$(call KCONFIG_ENABLE_OPT,CONFIG_NET))
$(if $(BR2_PACKAGE_LINUX_TOOLS_PERF),
$(call KCONFIG_ENABLE_OPT,CONFIG_PERF_EVENTS))
$(if $(BR2_LINUX_KERNEL_APPENDED_DTB),
$(call KCONFIG_ENABLE_OPT,CONFIG_ARM_APPENDED_DTB))
$(if $(LINUX_KERNEL_CUSTOM_LOGO_PATH),
$(call KCONFIG_ENABLE_OPT,CONFIG_FB)
$(call KCONFIG_ENABLE_OPT,CONFIG_LOGO)
$(call KCONFIG_ENABLE_OPT,CONFIG_LOGO_LINUX_CLUT224))
$(call KCONFIG_DISABLE_OPT,CONFIG_GCC_PLUGINS)
$(PACKAGES_LINUX_CONFIG_FIXUPS)
endef
ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)
# Starting with 4.17, the generated dtc parser code is no longer
# shipped with the kernel sources, so we need flex and bison. For
# reproducibility, we use our owns rather than the host ones.
LINUX_DEPENDENCIES += host-bison host-flex
ifeq ($(BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT),)
define LINUX_BUILD_DTB
$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_DTBS)
endef
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),)
define LINUX_INSTALL_DTB
# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
cp $(addprefix \
$(LINUX_ARCH_PATH)/boot/$(if $(wildcard \
$(addprefix $(LINUX_ARCH_PATH)/boot/dts/,$(LINUX_DTBS))),dts/),$(LINUX_DTBS)) \
$(1)
endef
endif # BR2_LINUX_KERNEL_APPENDED_DTB
endif # BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT
endif # BR2_LINUX_KERNEL_DTS_SUPPORT
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
# dtbs moved from arch/$ARCH/boot to arch/$ARCH/boot/dts since 3.8-rc1
define LINUX_APPEND_DTB
(cd $(LINUX_ARCH_PATH)/boot; \
for dtb in $(LINUX_DTS_NAME); do \
if test -e $${dtb}.dtb ; then \
dtbpath=$${dtb}.dtb ; \
else \
dtbpath=dts/$${dtb}.dtb ; \
fi ; \
cat zImage $${dtbpath} > zImage.$${dtb} || exit 1; \
done)
endef
ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
# We need to generate a new u-boot image that takes into
# account the extra-size added by the device tree at the end
# of the image. To do so, we first need to retrieve both load
# address and entry point for the kernel from the already
# generate uboot image before using mkimage -l.
LINUX_APPEND_DTB += ; \
MKIMAGE_ARGS=`$(MKIMAGE) -l $(LINUX_IMAGE_PATH) |\
sed -n -e 's/Image Name:[ ]*\(.*\)/-n \1/p' -e 's/Load Address:/-a/p' -e 's/Entry Point:/-e/p'`; \
for dtb in $(LINUX_DTS_NAME); do \
$(MKIMAGE) -A $(MKIMAGE_ARCH) -O linux \
-T kernel -C none $${MKIMAGE_ARGS} \
-d $(LINUX_ARCH_PATH)/boot/zImage.$${dtb} $(LINUX_IMAGE_PATH).$${dtb}; \
done
endif
endif
# Compilation. We make sure the kernel gets rebuilt when the
# configuration has changed. We call the 'all' and
# '$(LINUX_TARGET_NAME)' targets separately because calling them in
# the same $(MAKE) invocation has shown to cause parallel build
# issues.
# The call to disable gcc-plugins is a stop-gap measure:
# http://lists.busybox.net/pipermail/buildroot/2020-May/282727.html
define LINUX_BUILD_CMDS
$(call KCONFIG_DISABLE_OPT,CONFIG_GCC_PLUGINS)
$(foreach dts,$(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)), \
cp -f $(dts) $(LINUX_ARCH_PATH)/boot/dts/
)
$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) all
$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_TARGET_NAME)
$(LINUX_BUILD_DTB)
$(LINUX_APPEND_DTB)
endef
ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
# When a DTB was appended, install the potential several images with
# appended DTBs.
define LINUX_INSTALL_IMAGE
mkdir -p $(1)
cp $(LINUX_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME).* $(1)
endef
else
# Otherwise, just install the unique image generated by the kernel
# build process.
define LINUX_INSTALL_IMAGE
$(INSTALL) -m 0644 -D $(LINUX_IMAGE_PATH) $(1)/$(notdir $(LINUX_IMAGE_NAME))
endef
endif
ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET
$(call LINUX_INSTALL_IMAGE,$(TARGET_DIR)/boot)
$(call LINUX_INSTALL_DTB,$(TARGET_DIR)/boot)
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)/bin/linux-dtc ; \
$(if $(BR2_PACKAGE_HOST_DTC),,ln -sf linux-dtc $(HOST_DIR)/bin/dtc;) \
fi
endef
define LINUX_INSTALL_IMAGES_CMDS
$(call LINUX_INSTALL_IMAGE,$(BINARIES_DIR))
$(call LINUX_INSTALL_DTB,$(BINARIES_DIR))
endef
ifeq ($(BR2_STRIP_strip),y)
LINUX_MAKE_FLAGS += INSTALL_MOD_STRIP=1
endif
define LINUX_INSTALL_TARGET_CMDS
$(LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET)
# Install modules and remove symbolic links pointing to build
# directories, not relevant on the target
@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then \
$(LINUX_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) 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
# Run depmod in a target-finalize hook, to encompass modules installed by
# packages.
define LINUX_RUN_DEPMOD
if grep -q "CONFIG_MODULES=y" $(LINUX_DIR)/.config; then \
$(HOST_DIR)/sbin/depmod -a -b $(TARGET_DIR) $(LINUX_VERSION_PROBED); \
fi
endef
LINUX_TARGET_FINALIZE_HOOKS += LINUX_RUN_DEPMOD
# Include all our extensions.
#
# Note: our package infrastructure uses the full-path of the last-scanned
# Makefile to determine what package we're currently defining, using the
# last directory component in the path. Additionally, the full path of
# the package directory is also stored in _PKGDIR (e.g. to find patches)
#
# As such, including other Makefiles, like below, before we call one of
# the *-package macros usually doesn't work.
#
# However, by including the in-tree extensions after the ones from the
# br2-external trees, we're back to the situation where the last Makefile
# scanned *is* included from the correct directory.
#
# NOTE: this is very fragile, and extra care must be taken to ensure that
# we always end up with an in-tree included file. That's mostly OK, because
# we do have in-tree linux-extensions.
#
include $(sort $(wildcard $(foreach ext,$(BR2_EXTERNAL_DIRS), \
$(ext)/linux/linux-ext-*.mk)))
include $(sort $(wildcard linux/linux-ext-*.mk))
LINUX_PATCH_DEPENDENCIES += $(foreach ext,$(LINUX_EXTENSIONS),\
$(if $(BR2_LINUX_KERNEL_EXT_$(call UPPERCASE,$(ext))),$(ext)))
LINUX_PRE_PATCH_HOOKS += $(foreach ext,$(LINUX_EXTENSIONS),\
$(if $(BR2_LINUX_KERNEL_EXT_$(call UPPERCASE,$(ext))),\
$(call UPPERCASE,$(ext))_PREPARE_KERNEL))
# Checks to give errors that the user can understand
# When a custom repository has been set, check for the repository version
ifeq ($(BR2_LINUX_KERNEL_CUSTOM_SVN)$(BR2_LINUX_KERNEL_CUSTOM_GIT)$(BR2_LINUX_KERNEL_CUSTOM_HG),y)
ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION)),)
$(error No custom repository version set. Check your BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION setting)
endif
ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL)),)
$(error No custom repo URL set. Check your BR2_LINUX_KERNEL_CUSTOM_REPO_URL setting)
endif
endif
ifeq ($(BR_BUILDING),y)
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
# We must use the user-supplied kconfig value, because
# LINUX_KCONFIG_DEFCONFIG will at least contain the
# trailing _defconfig
ifeq ($(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 ($(LINUX_KCONFIG_FILE),)
$(error No kernel configuration file specified, check your BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE setting)
endif
endif
ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT):$(strip $(LINUX_DTS_NAME)),y:)
$(error No kernel device tree source specified, check your \
BR2_LINUX_KERNEL_INTREE_DTS_NAME / BR2_LINUX_KERNEL_CUSTOM_DTS_PATH settings)
endif
endif # BR_BUILDING
$(eval $(kconfig-package))
# Support for rebuilding the kernel after the cpio archive has
# been generated.
.PHONY: linux-rebuild-with-initramfs
linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_target_installed
linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_images_installed
linux-rebuild-with-initramfs: rootfs-cpio
linux-rebuild-with-initramfs:
@$(call MESSAGE,"Rebuilding kernel with initramfs")
# Build the kernel.
$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) $(LINUX_TARGET_NAME)
$(LINUX_APPEND_DTB)
# Copy the kernel image(s) to its(their) final destination
$(call LINUX_INSTALL_IMAGE,$(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)