xref: /OK3568_Linux_fs/buildroot/linux/linux.mk (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1################################################################################
2#
3# Linux kernel target
4#
5################################################################################
6
7LINUX_VERSION = $(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
8LINUX_LICENSE = GPL-2.0
9ifeq ($(BR2_LINUX_KERNEL_LATEST_VERSION),y)
10LINUX_LICENSE_FILES = \
11	COPYING \
12	LICENSES/preferred/GPL-2.0 \
13	LICENSES/exceptions/Linux-syscall-note
14endif
15LINUX_CPE_ID_VENDOR = linux
16LINUX_CPE_ID_PRODUCT = linux_kernel
17LINUX_CPE_ID_PREFIX = cpe:2.3:o
18
19# Compute LINUX_SOURCE and LINUX_SITE from the configuration
20ifeq ($(BR2_LINUX_KERNEL_CUSTOM_TARBALL),y)
21LINUX_TARBALL = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION))
22LINUX_SITE = $(patsubst %/,%,$(dir $(LINUX_TARBALL)))
23LINUX_SOURCE = $(notdir $(LINUX_TARBALL))
24else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_LOCAL),y)
25LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_LOCAL_LOCATION))
26LINUX_SITE_METHOD = local
27else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_GIT),y)
28LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
29LINUX_SITE_METHOD = git
30else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_HG),y)
31LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
32LINUX_SITE_METHOD = hg
33else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_SVN),y)
34LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
35LINUX_SITE_METHOD = svn
36else ifeq ($(BR2_LINUX_KERNEL_LATEST_CIP_VERSION)$(BR2_LINUX_KERNEL_LATEST_CIP_RT_VERSION),y)
37LINUX_SOURCE = linux-cip-$(LINUX_VERSION).tar.gz
38LINUX_SITE = https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/snapshot
39else ifneq ($(findstring -rc,$(LINUX_VERSION)),)
40# Since 4.12-rc1, -rc kernels are generated from cgit. This also works for
41# older -rc kernels.
42LINUX_SITE = https://git.kernel.org/torvalds/t
43else
44LINUX_SOURCE = linux-$(LINUX_VERSION).tar.xz
45ifeq ($(findstring x2.6.,x$(LINUX_VERSION)),x2.6.)
46LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v2.6
47else
48LINUX_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/v$(firstword $(subst ., ,$(LINUX_VERSION))).x
49endif
50endif
51
52ifeq ($(BR2_LINUX_KERNEL)$(BR2_LINUX_KERNEL_LATEST_VERSION),y)
53BR_NO_CHECK_HASH_FOR += $(LINUX_SOURCE)
54endif
55
56LINUX_PATCHES = $(call qstrip,$(BR2_LINUX_KERNEL_PATCH))
57
58# We have no way to know the hashes for user-supplied patches.
59BR_NO_CHECK_HASH_FOR += $(notdir $(LINUX_PATCHES))
60
61# We rely on the generic package infrastructure to download and apply
62# remote patches (downloaded from ftp, http or https). For local
63# patches, we can't rely on that infrastructure, because there might
64# be directories in the patch list (unlike for other packages).
65LINUX_PATCH = $(filter ftp://% http://% https://%,$(LINUX_PATCHES))
66
67# while the kernel is built for the target, the build may need various
68# host libraries depending on config (and version), so use
69# HOST_MAKE_ENV here. In particular, this ensures that our
70# host-pkgconf will look for host libraries and not target ones.
71LINUX_MAKE_ENV = \
72	$(HOST_MAKE_ENV) \
73	BR_BINARIES_DIR=$(BINARIES_DIR)
74
75LINUX_INSTALL_IMAGES = YES
76LINUX_DEPENDENCIES = host-kmod
77
78# The kernel CONFIG_EXTRA_FIRMWARE feature requires firmware files at build
79# time. Make sure they are available before the kernel builds.
80LINUX_DEPENDENCIES += \
81	$(if $(BR2_PACKAGE_INTEL_MICROCODE),intel-microcode) \
82	$(if $(BR2_PACKAGE_LINUX_FIRMWARE),linux-firmware) \
83	$(if $(BR2_PACKAGE_FIRMWARE_IMX),firmware-imx) \
84	$(if $(BR2_PACKAGE_WIRELESS_REGDB),wireless-regdb)
85
86# Starting with 4.16, the generated kconfig paser code is no longer
87# shipped with the kernel sources, so we need flex and bison, but
88# only if the host does not have them.
89LINUX_KCONFIG_DEPENDENCIES = \
90	$(BR2_BISON_HOST_DEPENDENCY) \
91	$(BR2_FLEX_HOST_DEPENDENCY)
92
93# Starting with 4.18, the kconfig in the kernel calls the
94# cross-compiler to check its capabilities. So we need the
95# toolchain before we can call the configurators.
96LINUX_KCONFIG_DEPENDENCIES += toolchain
97
98# host tools needed for kernel compression
99ifeq ($(BR2_LINUX_KERNEL_LZ4),y)
100LINUX_DEPENDENCIES += host-lz4
101else ifeq ($(BR2_LINUX_KERNEL_LZMA),y)
102LINUX_DEPENDENCIES += host-lzma
103else ifeq ($(BR2_LINUX_KERNEL_LZO),y)
104LINUX_DEPENDENCIES += host-lzop
105else ifeq ($(BR2_LINUX_KERNEL_XZ),y)
106LINUX_DEPENDENCIES += host-xz
107else ifeq ($(BR2_LINUX_KERNEL_ZSTD),y)
108LINUX_DEPENDENCIES += host-zstd
109endif
110LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_GZIP) += CONFIG_KERNEL_GZIP
111LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZ4) += CONFIG_KERNEL_LZ4
112LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZMA) += CONFIG_KERNEL_LZMA
113LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZO) += CONFIG_KERNEL_LZO
114LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_XZ) += CONFIG_KERNEL_XZ
115LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_ZSTD) += CONFIG_KERNEL_ZSTD
116LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_UNCOMPRESSED) += CONFIG_KERNEL_UNCOMPRESSED
117
118ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL),y)
119LINUX_DEPENDENCIES += host-openssl
120endif
121
122ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF),y)
123LINUX_DEPENDENCIES += host-elfutils host-pkgconf
124endif
125
126ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
127LINUX_DEPENDENCIES += host-pahole
128else
129define LINUX_FIXUP_CONFIG_PAHOLE_CHECK
130	if grep -q "^CONFIG_DEBUG_INFO_BTF=y" $(KCONFIG_DOT_CONFIG); then \
131		echo "To use CONFIG_DEBUG_INFO_BTF, enable host-pahole (BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE)" 1>&2; \
132		exit 1; \
133	fi
134endef
135endif
136
137# If host-uboot-tools is selected by the user, assume it is needed to
138# create a custom image
139ifeq ($(BR2_PACKAGE_HOST_UBOOT_TOOLS),y)
140LINUX_DEPENDENCIES += host-uboot-tools
141endif
142
143ifneq ($(ARCH_XTENSA_OVERLAY_FILE),)
144define LINUX_XTENSA_OVERLAY_EXTRACT
145	$(call arch-xtensa-overlay-extract,$(@D),linux)
146endef
147LINUX_POST_EXTRACT_HOOKS += LINUX_XTENSA_OVERLAY_EXTRACT
148LINUX_EXTRA_DOWNLOADS += $(ARCH_XTENSA_OVERLAY_URL)
149endif
150
151# We don't want to run depmod after installing the kernel. It's done in a
152# target-finalize hook, to encompass modules installed by packages.
153# Disable building host tools with -Werror: newer gcc versions can be
154# extra picky about some code (https://bugs.busybox.net/show_bug.cgi?id=14826)
155LINUX_MAKE_FLAGS = \
156	HOSTCC="$(HOSTCC) $(subst -I/,-isystem /,$(subst -I /,-isystem /,$(HOST_CFLAGS))) $(HOST_LDFLAGS)" \
157	ARCH=$(KERNEL_ARCH) \
158	INSTALL_MOD_PATH=$(TARGET_DIR) \
159	CROSS_COMPILE="$(TARGET_CROSS)" \
160	WERROR=0 \
161	REGENERATE_PARSERS=1 \
162	DEPMOD=$(HOST_DIR)/sbin/depmod
163
164ifeq ($(BR2_REPRODUCIBLE),y)
165LINUX_MAKE_ENV += \
166	KBUILD_BUILD_VERSION=1 \
167	KBUILD_BUILD_USER=buildroot \
168	KBUILD_BUILD_HOST=buildroot \
169	KBUILD_BUILD_TIMESTAMP="$(shell LC_ALL=C TZ='UTC' date -d @$(SOURCE_DATE_EPOCH))"
170endif
171
172# gcc-8 started warning about function aliases that have a
173# non-matching prototype.  This seems rather useful in general, but it
174# causes tons of warnings in the Linux kernel, where we rely on
175# abusing those aliases for system call entry points, in order to
176# sanitize the arguments passed from user space in registers.
177# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82435
178ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_8),y)
179LINUX_MAKE_ENV += KCFLAGS=-Wno-attribute-alias
180endif
181
182ifeq ($(BR2_LINUX_KERNEL_DTB_OVERLAY_SUPPORT),y)
183LINUX_MAKE_ENV += DTC_FLAGS=-@
184endif
185
186# Get the real Linux version, which tells us where kernel modules are
187# going to be installed in the target filesystem.
188# Filter out 'w' from MAKEFLAGS, to workaround a bug in make 4.1 (#13141)
189LINUX_VERSION_PROBED = `MAKEFLAGS='$(filter-out w,$(MAKEFLAGS))' $(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) --no-print-directory -s kernelrelease 2>/dev/null`
190
191LINUX_DTS_NAME += $(call qstrip,$(BR2_LINUX_KERNEL_INTREE_DTS_NAME))
192
193# We keep only the .dts files, so that the user can specify both .dts
194# and .dtsi files in BR2_LINUX_KERNEL_CUSTOM_DTS_PATH. Both will be
195# copied to arch/<arch>/boot/dts, but only the .dts files will
196# actually be generated as .dtb.
197LINUX_DTS_NAME += $(basename $(filter %.dts,$(notdir $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)))))
198
199LINUX_DTBS = $(addsuffix .dtb,$(LINUX_DTS_NAME))
200
201ifeq ($(BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM),y)
202LINUX_IMAGE_NAME = $(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_NAME))
203LINUX_TARGET_NAME = $(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_TARGET_NAME))
204ifeq ($(LINUX_IMAGE_NAME),)
205LINUX_IMAGE_NAME = $(LINUX_TARGET_NAME)
206endif
207else
208ifeq ($(BR2_LINUX_KERNEL_UIMAGE),y)
209LINUX_IMAGE_NAME = uImage
210else ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
211LINUX_IMAGE_NAME = uImage
212else ifeq ($(BR2_LINUX_KERNEL_BZIMAGE),y)
213LINUX_IMAGE_NAME = bzImage
214else ifeq ($(BR2_LINUX_KERNEL_ZIMAGE),y)
215LINUX_IMAGE_NAME = zImage
216else ifeq ($(BR2_LINUX_KERNEL_ZIMAGE_EPAPR),y)
217LINUX_IMAGE_NAME = zImage.epapr
218else ifeq ($(BR2_LINUX_KERNEL_APPENDED_ZIMAGE),y)
219LINUX_IMAGE_NAME = zImage
220else ifeq ($(BR2_LINUX_KERNEL_CUIMAGE),y)
221LINUX_IMAGE_NAME = cuImage.$(firstword $(LINUX_DTS_NAME))
222else ifeq ($(BR2_LINUX_KERNEL_SIMPLEIMAGE),y)
223LINUX_IMAGE_NAME = simpleImage.$(firstword $(LINUX_DTS_NAME))
224else ifeq ($(BR2_LINUX_KERNEL_IMAGE),y)
225LINUX_IMAGE_NAME = Image
226else ifeq ($(BR2_LINUX_KERNEL_IMAGEGZ),y)
227LINUX_IMAGE_NAME = Image.gz
228else ifeq ($(BR2_LINUX_KERNEL_LINUX_BIN),y)
229LINUX_IMAGE_NAME = linux.bin
230else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
231LINUX_IMAGE_NAME = vmlinux.bin
232else ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
233LINUX_IMAGE_NAME = vmlinux
234else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ),y)
235LINUX_IMAGE_NAME = vmlinuz
236else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ_BIN),y)
237LINUX_IMAGE_NAME = vmlinuz.bin
238endif
239# The if-else blocks above are all the image types we know of, and all
240# come from a Kconfig choice, so we know we have LINUX_IMAGE_NAME set
241# to something
242LINUX_TARGET_NAME = $(LINUX_IMAGE_NAME)
243endif
244
245LINUX_KERNEL_UIMAGE_LOADADDR = $(call qstrip,$(BR2_LINUX_KERNEL_UIMAGE_LOADADDR))
246ifneq ($(LINUX_KERNEL_UIMAGE_LOADADDR),)
247LINUX_MAKE_FLAGS += LOADADDR="$(LINUX_KERNEL_UIMAGE_LOADADDR)"
248endif
249
250# Compute the arch path, since i386 and x86_64 are in arch/x86 and not
251# in arch/$(KERNEL_ARCH). Even if the kernel creates symbolic links
252# for bzImage, arch/i386 and arch/x86_64 do not exist when copying the
253# defconfig file.
254ifeq ($(KERNEL_ARCH),i386)
255LINUX_ARCH_PATH = $(LINUX_DIR)/arch/x86
256else ifeq ($(KERNEL_ARCH),x86_64)
257LINUX_ARCH_PATH = $(LINUX_DIR)/arch/x86
258else ifeq ($(KERNEL_ARCH),sparc64)
259LINUX_ARCH_PATH = $(LINUX_DIR)/arch/sparc
260else
261LINUX_ARCH_PATH = $(LINUX_DIR)/arch/$(KERNEL_ARCH)
262endif
263
264ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
265LINUX_IMAGE_PATH = $(LINUX_DIR)/$(LINUX_IMAGE_NAME)
266else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ),y)
267LINUX_IMAGE_PATH = $(LINUX_DIR)/$(LINUX_IMAGE_NAME)
268else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ_BIN),y)
269LINUX_IMAGE_PATH = $(LINUX_DIR)/$(LINUX_IMAGE_NAME)
270else
271LINUX_IMAGE_PATH = $(LINUX_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME)
272endif # BR2_LINUX_KERNEL_VMLINUX
273
274define LINUX_APPLY_LOCAL_PATCHES
275	for p in $(filter-out ftp://% http://% https://%,$(LINUX_PATCHES)) ; do \
276		if test -d $$p ; then \
277			$(APPLY_PATCHES) $(@D) $$p \*.patch || exit 1 ; \
278		else \
279			$(APPLY_PATCHES) $(@D) `dirname $$p` `basename $$p` || exit 1; \
280		fi \
281	done
282endef
283
284LINUX_POST_PATCH_HOOKS += LINUX_APPLY_LOCAL_PATCHES
285
286# Older versions break on gcc 10+ because of redefined symbols
287define LINUX_DROP_YYLLOC
288	$(Q)grep -Z -l -r -E '^YYLTYPE yylloc;$$' $(@D) \
289	|xargs -0 -r $(SED) '/^YYLTYPE yylloc;$$/d'
290endef
291LINUX_POST_PATCH_HOOKS += LINUX_DROP_YYLLOC
292
293# Kernel version < 5.6 breaks if host-gcc version is >= 10 and
294# 'yylloc' symbol is removed in previous hook, due to missing
295# '%locations' bison directive in dtc-parser.y.  See:
296# https://bugs.busybox.net/show_bug.cgi?id=14971
297define LINUX_ADD_DTC_LOCATIONS
298	$(Q)DTC_PARSER=$(@D)/scripts/dtc/dtc-parser.y; \
299	if test -e "$${DTC_PARSER}" \
300		&& ! grep -Eq '^%locations$$' "$${DTC_PARSER}" ; then \
301		$(SED) '/^%{$$/i %locations' "$${DTC_PARSER}"; \
302	fi
303endef
304LINUX_POST_PATCH_HOOKS += LINUX_ADD_DTC_LOCATIONS
305
306# Older linux kernels use deprecated perl constructs in timeconst.pl
307# that were removed for perl 5.22+ so it breaks on newer distributions
308# Try a dry-run patch to see if this applies, if it does go ahead
309define LINUX_TRY_PATCH_TIMECONST
310	@if patch -p1 --dry-run -f -s -d $(@D) <$(LINUX_PKGDIR)/0001-timeconst.pl-Eliminate-Perl-warning.patch.conditional >/dev/null ; then \
311		$(APPLY_PATCHES) $(@D) $(LINUX_PKGDIR) 0001-timeconst.pl-Eliminate-Perl-warning.patch.conditional ; \
312	fi
313endef
314LINUX_POST_PATCH_HOOKS += LINUX_TRY_PATCH_TIMECONST
315
316LINUX_KERNEL_CUSTOM_LOGO_PATH = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_LOGO_PATH))
317ifneq ($(LINUX_KERNEL_CUSTOM_LOGO_PATH),)
318LINUX_DEPENDENCIES += host-imagemagick
319define LINUX_KERNEL_CUSTOM_LOGO_CONVERT
320	$(HOST_DIR)/bin/convert $(LINUX_KERNEL_CUSTOM_LOGO_PATH) \
321		-dither None -colors 224 -compress none \
322		$(LINUX_DIR)/drivers/video/logo/logo_linux_clut224.ppm
323endef
324LINUX_PRE_BUILD_HOOKS += LINUX_KERNEL_CUSTOM_LOGO_CONVERT
325endif
326
327ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
328LINUX_KCONFIG_DEFCONFIG = $(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG))_defconfig
329else ifeq ($(BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG),y)
330ifeq ($(BR2_powerpc64le),y)
331LINUX_KCONFIG_DEFCONFIG = ppc64le_defconfig
332else
333LINUX_KCONFIG_DEFCONFIG = defconfig
334endif
335else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
336LINUX_KCONFIG_FILE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE))
337endif
338LINUX_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES))
339LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
340
341# LINUX_MAKE_FLAGS overrides HOSTCC to allow the kernel build to find
342# our host-openssl and host-libelf. However, this triggers a bug in
343# the kconfig build script that causes it to build with
344# /usr/include/ncurses.h (which is typically wchar) but link with
345# $(HOST_DIR)/lib/libncurses.so (which is not).  We don't actually
346# need any host-package for kconfig, so remove the HOSTCC override
347# again. In addition, even though linux depends on the toolchain and
348# therefore host-ccache would be ready, we use HOSTCC_NOCCACHE for
349# consistency with other kconfig packages.
350LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS) HOSTCC="$(HOSTCC_NOCCACHE)"
351
352# If no package has yet set it, set it from the Kconfig option
353LINUX_NEEDS_MODULES ?= $(BR2_LINUX_NEEDS_MODULES)
354
355# Make sure the Linux kernel is built with the right endianness. Not
356# all architectures support
357# CONFIG_CPU_BIG_ENDIAN/CONFIG_CPU_LITTLE_ENDIAN in Linux, but the
358# option will be thrown away and ignored if it doesn't exist.
359ifeq ($(BR2_ENDIAN),"BIG")
360define LINUX_FIXUP_CONFIG_ENDIANNESS
361	$(call KCONFIG_ENABLE_OPT,CONFIG_CPU_BIG_ENDIAN)
362endef
363else
364define LINUX_FIXUP_CONFIG_ENDIANNESS
365	$(call KCONFIG_ENABLE_OPT,CONFIG_CPU_LITTLE_ENDIAN)
366endef
367endif
368
369define LINUX_KCONFIG_FIXUP_CMDS
370	$(if $(LINUX_NEEDS_MODULES),
371		$(call KCONFIG_ENABLE_OPT,CONFIG_MODULES))
372	$(call KCONFIG_ENABLE_OPT,$(strip $(LINUX_COMPRESSION_OPT_y)))
373	$(foreach opt, $(LINUX_COMPRESSION_OPT_),
374		$(call KCONFIG_DISABLE_OPT,$(opt))
375	)
376	$(LINUX_FIXUP_CONFIG_ENDIANNESS)
377	$(LINUX_FIXUP_CONFIG_PAHOLE_CHECK)
378	$(if $(BR2_arm)$(BR2_armeb),
379		$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI))
380	$(if $(BR2_powerpc)$(BR2_powerpc64)$(BR2_powerpc64le),
381		$(call KCONFIG_ENABLE_OPT,CONFIG_PPC_DISABLE_WERROR))
382	$(if $(BR2_ARC_PAGE_SIZE_4K),
383		$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
384		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
385		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
386	$(if $(BR2_ARC_PAGE_SIZE_8K),
387		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
388		$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
389		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
390	$(if $(BR2_ARC_PAGE_SIZE_16K),
391		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_4K)
392		$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_PAGE_SIZE_8K)
393		$(call KCONFIG_ENABLE_OPT,CONFIG_ARC_PAGE_SIZE_16K))
394	$(if $(BR2_ARM64_PAGE_SIZE_4K),
395		$(call KCONFIG_ENABLE_OPT,CONFIG_ARM64_4K_PAGES)
396		$(call KCONFIG_DISABLE_OPT,CONFIG_ARM64_16K_PAGES)
397		$(call KCONFIG_DISABLE_OPT,CONFIG_ARM64_64K_PAGES))
398	$(if $(BR2_ARM64_PAGE_SIZE_64K),
399		$(call KCONFIG_DISABLE_OPT,CONFIG_ARM64_4K_PAGES)
400		$(call KCONFIG_DISABLE_OPT,CONFIG_ARM64_16K_PAGES)
401		$(call KCONFIG_ENABLE_OPT,CONFIG_ARM64_64K_PAGES))
402	$(if $(BR2_TARGET_ROOTFS_CPIO),
403		$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD))
404	# As the kernel gets compiled before root filesystems are
405	# built, we create a fake cpio file. It'll be
406	# replaced later by the real cpio archive, and the kernel will be
407	# rebuilt using the linux-rebuild-with-initramfs target.
408	$(if $(BR2_TARGET_ROOTFS_INITRAMFS),
409		mkdir -p $(BINARIES_DIR)
410		touch $(BINARIES_DIR)/rootfs.cpio
411		$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,"$${BR_BINARIES_DIR}/rootfs.cpio")
412		$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0)
413		$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0))
414	$(if $(BR2_ROOTFS_DEVICE_CREATION_STATIC),,
415		$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS)
416		$(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT))
417	$(if $(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV),
418		$(call KCONFIG_ENABLE_OPT,CONFIG_INOTIFY_USER))
419	$(if $(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),
420		$(call KCONFIG_ENABLE_OPT,CONFIG_NET))
421	$(if $(BR2_LINUX_KERNEL_APPENDED_DTB),
422		$(call KCONFIG_ENABLE_OPT,CONFIG_ARM_APPENDED_DTB))
423	$(if $(LINUX_KERNEL_CUSTOM_LOGO_PATH),
424		$(call KCONFIG_ENABLE_OPT,CONFIG_FB)
425		$(call KCONFIG_ENABLE_OPT,CONFIG_LOGO)
426		$(call KCONFIG_ENABLE_OPT,CONFIG_LOGO_LINUX_CLUT224))
427	$(call KCONFIG_DISABLE_OPT,CONFIG_GCC_PLUGINS)
428	$(PACKAGES_LINUX_CONFIG_FIXUPS)
429endef
430
431ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)
432# Starting with 4.17, the generated dtc parser code is no longer
433# shipped with the kernel sources, so we need flex and bison. For
434# reproducibility, we use our owns rather than the host ones.
435LINUX_DEPENDENCIES += host-bison host-flex
436
437ifeq ($(BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT),)
438define LINUX_BUILD_DTB
439	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_DTBS)
440endef
441ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),)
442define LINUX_INSTALL_DTB
443	# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
444	$(foreach dtb,$(LINUX_DTBS), \
445		install -D \
446			$(or $(wildcard $(LINUX_ARCH_PATH)/boot/dts/$(dtb)),$(LINUX_ARCH_PATH)/boot/$(dtb)) \
447			$(1)/$(if $(BR2_LINUX_KERNEL_DTB_KEEP_DIRNAME),$(dtb),$(notdir $(dtb)))
448	)
449endef
450endif # BR2_LINUX_KERNEL_APPENDED_DTB
451endif # BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT
452endif # BR2_LINUX_KERNEL_DTS_SUPPORT
453
454ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
455# dtbs moved from arch/$ARCH/boot to arch/$ARCH/boot/dts since 3.8-rc1
456define LINUX_APPEND_DTB
457	(cd $(LINUX_ARCH_PATH)/boot; \
458		for dtb in $(LINUX_DTS_NAME); do \
459			if test -e $${dtb}.dtb ; then \
460				dtbpath=$${dtb}.dtb ; \
461			else \
462				dtbpath=dts/$${dtb}.dtb ; \
463			fi ; \
464			cat zImage $${dtbpath} > zImage.$${dtb} || exit 1; \
465		done)
466endef
467ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
468# We need to generate a new u-boot image that takes into
469# account the extra-size added by the device tree at the end
470# of the image. To do so, we first need to retrieve both load
471# address and entry point for the kernel from the already
472# generate uboot image before using mkimage -l.
473LINUX_APPEND_DTB += ; \
474	MKIMAGE_ARGS=`$(MKIMAGE) -l $(LINUX_IMAGE_PATH) |\
475	sed -n -e 's/Image Name:[ ]*\(.*\)/-n \1/p' -e 's/Load Address:/-a/p' -e 's/Entry Point:/-e/p'`; \
476	for dtb in $(LINUX_DTS_NAME); do \
477		$(MKIMAGE) -A $(MKIMAGE_ARCH) -O linux \
478			-T kernel -C none $${MKIMAGE_ARGS} \
479			-d $(LINUX_ARCH_PATH)/boot/zImage.$${dtb} $(LINUX_IMAGE_PATH).$${dtb}; \
480	done
481endif
482endif
483
484# Compilation. We make sure the kernel gets rebuilt when the
485# configuration has changed. We call the 'all' and
486# '$(LINUX_TARGET_NAME)' targets separately because calling them in
487# the same $(MAKE) invocation has shown to cause parallel build
488# issues.
489# The call to disable gcc-plugins is a stop-gap measure:
490#   http://lists.busybox.net/pipermail/buildroot/2020-May/282727.html
491define LINUX_BUILD_CMDS
492	$(call KCONFIG_DISABLE_OPT,CONFIG_GCC_PLUGINS)
493	$(foreach dts,$(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)), \
494		cp -f $(dts) $(LINUX_ARCH_PATH)/boot/dts/
495	)
496	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) all
497	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_TARGET_NAME)
498	$(LINUX_BUILD_DTB)
499	$(LINUX_APPEND_DTB)
500endef
501
502ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
503# When a DTB was appended, install the potential several images with
504# appended DTBs.
505define LINUX_INSTALL_IMAGE
506	mkdir -p $(1)
507	cp $(LINUX_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME).* $(1)
508endef
509else
510# Otherwise, just install the unique image generated by the kernel
511# build process.
512define LINUX_INSTALL_IMAGE
513	$(INSTALL) -m 0644 -D $(LINUX_IMAGE_PATH) $(1)/$(notdir $(LINUX_IMAGE_NAME))
514endef
515endif
516
517ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
518define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET
519	$(call LINUX_INSTALL_IMAGE,$(TARGET_DIR)/boot)
520	$(call LINUX_INSTALL_DTB,$(TARGET_DIR)/boot)
521endef
522endif
523
524define LINUX_INSTALL_HOST_TOOLS
525	# Installing dtc (device tree compiler) as host tool, if selected
526	if grep -q "CONFIG_DTC=y" $(@D)/.config; then \
527		$(INSTALL) -D -m 0755 $(@D)/scripts/dtc/dtc $(HOST_DIR)/bin/linux-dtc ; \
528		$(if $(BR2_PACKAGE_HOST_DTC),,ln -sf linux-dtc $(HOST_DIR)/bin/dtc;) \
529	fi
530endef
531
532define LINUX_INSTALL_IMAGES_CMDS
533	$(call LINUX_INSTALL_IMAGE,$(BINARIES_DIR))
534	$(call LINUX_INSTALL_DTB,$(BINARIES_DIR))
535endef
536
537ifeq ($(BR2_STRIP_strip),y)
538LINUX_MAKE_FLAGS += INSTALL_MOD_STRIP=1
539endif
540
541define LINUX_INSTALL_TARGET_CMDS
542	$(LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET)
543	# Install modules and remove symbolic links pointing to build
544	# directories, not relevant on the target
545	@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then \
546		$(LINUX_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) modules_install; \
547		rm -f $(TARGET_DIR)/lib/modules/$(LINUX_VERSION_PROBED)/build ; \
548		rm -f $(TARGET_DIR)/lib/modules/$(LINUX_VERSION_PROBED)/source ; \
549	fi
550	$(LINUX_INSTALL_HOST_TOOLS)
551endef
552
553# Run depmod in a target-finalize hook, to encompass modules installed by
554# packages.
555define LINUX_RUN_DEPMOD
556	if test -d $(TARGET_DIR)/lib/modules/$(LINUX_VERSION_PROBED) \
557		&& grep -q "CONFIG_MODULES=y" $(LINUX_DIR)/.config; then \
558		$(HOST_DIR)/sbin/depmod -a -b $(TARGET_DIR) $(LINUX_VERSION_PROBED); \
559	fi
560endef
561LINUX_TARGET_FINALIZE_HOOKS += LINUX_RUN_DEPMOD
562
563# Include all our extensions.
564#
565# Note: our package infrastructure uses the full-path of the last-scanned
566# Makefile to determine what package we're currently defining, using the
567# last directory component in the path. Additionally, the full path of
568# the package directory is also stored in _PKGDIR (e.g. to find patches)
569#
570# As such, including other Makefiles, like below, before we call one of
571# the *-package macros usually doesn't work.
572#
573# However, by including the in-tree extensions after the ones from the
574# br2-external trees, we're back to the situation where the last Makefile
575# scanned *is* included from the correct directory.
576#
577# NOTE: this is very fragile, and extra care must be taken to ensure that
578# we always end up with an in-tree included file. That's mostly OK, because
579# we do have in-tree linux-extensions.
580#
581include $(sort $(wildcard $(foreach ext,$(BR2_EXTERNAL_DIRS), \
582	$(ext)/linux/linux-ext-*.mk)))
583include $(sort $(wildcard linux/linux-ext-*.mk))
584
585LINUX_PATCH_DEPENDENCIES += $(foreach ext,$(LINUX_EXTENSIONS),\
586	$(if $(BR2_LINUX_KERNEL_EXT_$(call UPPERCASE,$(ext))),$(ext)))
587
588LINUX_PRE_PATCH_HOOKS += $(foreach ext,$(LINUX_EXTENSIONS),\
589	$(if $(BR2_LINUX_KERNEL_EXT_$(call UPPERCASE,$(ext))),\
590		$(call UPPERCASE,$(ext))_PREPARE_KERNEL))
591
592# Checks to give errors that the user can understand
593
594# When a custom repository has been set, check for the repository version
595ifeq ($(BR2_LINUX_KERNEL_CUSTOM_SVN)$(BR2_LINUX_KERNEL_CUSTOM_GIT)$(BR2_LINUX_KERNEL_CUSTOM_HG),y)
596ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION)),)
597$(error No custom repository version set. Check your BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION setting)
598endif
599ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL)),)
600$(error No custom repo URL set. Check your BR2_LINUX_KERNEL_CUSTOM_REPO_URL setting)
601endif
602endif
603
604ifeq ($(BR_BUILDING),y)
605
606ifeq ($(BR2_LINUX_KERNEL_CUSTOM_VERSION),y)
607ifeq ($(LINUX_VERSION),)
608$(error No custom kernel version set. Check your BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE setting)
609endif
610endif
611
612ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
613# We must use the user-supplied kconfig value, because
614# LINUX_KCONFIG_DEFCONFIG will at least contain the
615# trailing _defconfig
616ifeq ($(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG)),)
617$(error No kernel defconfig name specified, check your BR2_LINUX_KERNEL_DEFCONFIG setting)
618endif
619endif
620
621ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
622ifeq ($(LINUX_KCONFIG_FILE),)
623$(error No kernel configuration file specified, check your BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE setting)
624endif
625endif
626
627ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT):$(strip $(LINUX_DTS_NAME)),y:)
628$(error No kernel device tree source specified, check your \
629	BR2_LINUX_KERNEL_INTREE_DTS_NAME / BR2_LINUX_KERNEL_CUSTOM_DTS_PATH settings)
630endif
631
632endif # BR_BUILDING
633
634$(eval $(kconfig-package))
635
636# Support for rebuilding the kernel after the cpio archive has
637# been generated.
638.PHONY: linux-rebuild-with-initramfs
639linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_target_installed
640linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_images_installed
641linux-rebuild-with-initramfs: rootfs-cpio
642linux-rebuild-with-initramfs:
643	@$(call MESSAGE,"Rebuilding kernel with initramfs")
644	# Build the kernel.
645	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) $(LINUX_TARGET_NAME)
646	$(LINUX_APPEND_DTB)
647	# Copy the kernel image(s) to its(their) final destination
648	$(call LINUX_INSTALL_IMAGE,$(BINARIES_DIR))
649	# If there is a .ub file copy it to the final destination
650	test ! -f $(LINUX_IMAGE_PATH).ub || cp $(LINUX_IMAGE_PATH).ub $(BINARIES_DIR)
651