538898d5ed
Backports provide drivers released on newer kernels backported for usage on older kernels. There are two versions of linux-backports: one that supports Linux kernels >= 3.0 and one supports even older kernels. We're only packaging the version that supports >= 3.0. linux-backports needs to have access to the kernel's .config to extract information it reintroduces as blind options in generated Kconfig snippets for its own menuconfig. However, Buildroot offers no way to express this kind of dependency. So we need to hand-write a dependency from linux-backports' own .config to linux' .config . Since linux.mk has not already been sourced by the time we source linux-backports.mk, we are missing the definition for LINUX_DIR, so we can not use it our rule. Fortunately, make provides so-called "secondary expansion", by which rules which dependencies include a $$-dereferenced variable wil lbe re-evaluated after all the rest of the Makefiles have been parsed. So, we use that secondary expansion to post-pone evaluation of that dependency so we can use LINUX_DIR. Note: reconstructing LINUX_DIR by hand does not work, because of the custom archives, git tree, or override-srcdir. Signed-off-by: Petr Vorel <petr.vorel@gmail.com> Cc: Arnout Vandecappelle <arnout@mind.be> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: "Yann E. MORIN" <yann.morin.1998@free.fr> Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr> Reviewed-by: Romain Naour <romain.naour@openwide.fr> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
88 lines
3.4 KiB
Makefile
88 lines
3.4 KiB
Makefile
################################################################################
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#
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# linux-backports
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#
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################################################################################
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LINUX_BACKPORTS_VERSION_MAJOR = 4.1.1
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LINUX_BACKPORTS_VERSION = $(LINUX_BACKPORTS_VERSION_MAJOR)-1
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LINUX_BACKPORTS_SOURCE = backports-$(LINUX_BACKPORTS_VERSION).tar.xz
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LINUX_BACKPORTS_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/projects/backports/stable/v$(LINUX_BACKPORTS_VERSION_MAJOR)
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LINUX_BACKPORTS_LICENSE = GPLv2
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LINUX_BACKPORTS_LICENSE_FILES = COPYING
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LINUX_BACKPORTS_DEPENDENCIES = linux
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LINUX_BACKPORTS_MAKE_OPTS = \
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$(LINUX_MAKE_FLAGS) \
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KLIB_BUILD=$(LINUX_DIR) \
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KLIB=$(TARGET_DIR)
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ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG),y)
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LINUX_BACKPORTS_KCONFIG_FILE = $(LINUX_BACKPORTS_DIR)/defconfigs/$(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG))
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else ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG),y)
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LINUX_BACKPORTS_KCONFIG_FILE = $(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE))
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endif
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define LINUX_BACKPORTS_BUILD_CMDS
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$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_BACKPORTS_MAKE_OPTS) -C $(@D)
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endef
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define LINUX_BACKPORTS_INSTALL_TARGET_CMDS
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$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_BACKPORTS_MAKE_OPTS) \
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-C $(LINUX_DIR) M=$(@D) \
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INSTALL_MOD_DIR=backports \
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modules_install
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endef
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LINUX_BACKPORTS_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CONFIG_FRAGMENT_FILES))
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LINUX_BACKPORTS_KCONFIG_OPTS = $(LINUX_BACKPORTS_MAKE_OPTS)
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# Checks to give errors that the user can understand
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ifeq ($(BR_BUILDING),y)
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ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG),y)
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ifeq ($(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG)),)
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$(error No linux-backports defconfig name specified, check your BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG setting)
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endif
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endif
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ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG),y)
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ifeq ($(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE)),)
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$(error No linux-backports configuration file specified, check your BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE setting)
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endif
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endif
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endif # BR_BUILDING
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$(eval $(kconfig-package))
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# linux-backports' own .config file needs options from the kernel's own
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# .config file. The dependencies handling in the infrastructure does not
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# allow to express this kind of dependencies. Besides, linux.mk might
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# not have been parsed yet, so the Linux build dir LINUX_DIR is not yet
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# known. Thus, we use a "secondary expansion" so the rule is re-evaluated
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# after all Makefiles are parsed, and thus at that time we will have the
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# LINUX_DIR variable set to the proper value.
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#
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# Furthermore, we want to check the kernel version, since linux-backports
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# only supports kernels >= 3.0. To avoid overriding linux-backports'
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# .config rule defined in the kconfig-package infra, we use an
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# intermediate stamp-file.
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#
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# Finally, it must also come after the call to kconfig-package, so we get
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# LINUX_BACKPORTS_DIR properly defined (because the target part of the
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# rule is not re-evaluated).
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#
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$(LINUX_BACKPORTS_DIR)/.config: $(LINUX_BACKPORTS_DIR)/.stamp_check_kernel_version
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.SECONDEXPANSION:
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$(LINUX_BACKPORTS_DIR)/.stamp_check_kernel_version: $$(LINUX_DIR)/.config
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$(Q)LINUX_VERSION_PROBED=$(LINUX_VERSION_PROBED); \
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if [ $${LINUX_VERSION_PROBED%%.*} -lt 3 ]; then \
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printf "Linux version '%s' is too old for linux-backports (needs 3.0 or later)\n" \
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"$${LINUX_VERSION_PROBED}"; \
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exit 1; \
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fi
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$(Q)touch $(@)
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