Commit 538898d5 authored by Petr Vorel's avatar Petr Vorel Committed by Thomas Petazzoni
Browse files

package/linux-backports: new package 



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: default avatarPetr 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: default avatarYann E. MORIN <yann.morin.1998@free.fr>
Reviewed-by: default avatarRomain Naour <romain.naour@openwide.fr>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
parent 16d7f4af

package/Config.in

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@@ -372,6 +372,7 @@ endif 
	source "package/kbd/Config.in"

	source "package/lcdproc/Config.in"

	source "package/libump/Config.in"

	source "package/linux-backports/Config.in"

	source "package/lirc-tools/Config.in"

	source "package/lm-sensors/Config.in"

	source "package/lshw/Config.in"

package/linux-backports/Config.in

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comment "linux-backports needs a Linux kernel to be built"

	depends on !BR2_LINUX_KERNEL



config BR2_PACKAGE_LINUX_BACKPORTS

	bool "linux-backports"

	depends on BR2_LINUX_KERNEL

	help

	  The linux-backports package includes many Linux drivers from

	  recent kernels, backported to older ones.



	  This version of linux-backports supports kernels starting from 3.0.



	  https://backports.wiki.kernel.org



if BR2_PACKAGE_LINUX_BACKPORTS



choice

	prompt "Linux kernel driver backports configuration"

	default BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG



config BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG

	bool "Using an in-tree defconfig file"



config BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG

	bool "Using a custom (def)config file"



endchoice



config BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG

	string "Defconfig name"

	depends on BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG

	help

	  Name of the backports defconfig file to use, without the

	  leading defconfig-. The defconfig is located in defconfigs/

	  directory in the backports tree.



config BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE

	string "Configuration file path"

	depends on BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG

	help

	  Path to the backports configuration file



	  Note: this can be a defconfig file or a complete .config file,

	  which can later be saved back with make linux-update-(def)config.



config BR2_PACKAGE_LINUX_BACKPORTS_CONFIG_FRAGMENT_FILES

	string "Additional configuration fragment files"

	help

	  A space-separated list of configuration fragment files, that

	  will be merged to the main linux-backports configuration file.



endif # BR2_PACKAGE_LINUX_BACKPORTS

package/linux-backports/linux-backports.hash

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# From: https://www.kernel.org/pub/linux/kernel/projects/backports/stable/v4.1.1/sha256sums.asc

sha256 7fca160665b801796ce50def18f2fd6def1c4452290e93ec5332444fb2021bd6  backports-4.1.1-1.tar.xz

package/linux-backports/linux-backports.mk

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################################################################################

#

# linux-backports

#

################################################################################



LINUX_BACKPORTS_VERSION_MAJOR = 4.1.1

LINUX_BACKPORTS_VERSION = $(LINUX_BACKPORTS_VERSION_MAJOR)-1

LINUX_BACKPORTS_SOURCE = backports-$(LINUX_BACKPORTS_VERSION).tar.xz

LINUX_BACKPORTS_SITE = $(BR2_KERNEL_MIRROR)/linux/kernel/projects/backports/stable/v$(LINUX_BACKPORTS_VERSION_MAJOR)

LINUX_BACKPORTS_LICENSE = GPLv2

LINUX_BACKPORTS_LICENSE_FILES = COPYING



LINUX_BACKPORTS_DEPENDENCIES = linux



LINUX_BACKPORTS_MAKE_OPTS = \

	$(LINUX_MAKE_FLAGS) \

	KLIB_BUILD=$(LINUX_DIR) \

	KLIB=$(TARGET_DIR)



ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG),y)

LINUX_BACKPORTS_KCONFIG_FILE = $(LINUX_BACKPORTS_DIR)/defconfigs/$(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG))

else ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG),y)

LINUX_BACKPORTS_KCONFIG_FILE = $(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE))

endif



define LINUX_BACKPORTS_BUILD_CMDS

	$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_BACKPORTS_MAKE_OPTS) -C $(@D)

endef



define LINUX_BACKPORTS_INSTALL_TARGET_CMDS

	$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_BACKPORTS_MAKE_OPTS) \

		-C $(LINUX_DIR) M=$(@D) \

		INSTALL_MOD_DIR=backports \

		modules_install

endef



LINUX_BACKPORTS_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CONFIG_FRAGMENT_FILES))

LINUX_BACKPORTS_KCONFIG_OPTS = $(LINUX_BACKPORTS_MAKE_OPTS)



# Checks to give errors that the user can understand

ifeq ($(BR_BUILDING),y)



ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_DEFCONFIG),y)

ifeq ($(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG)),)

$(error No linux-backports defconfig name specified, check your BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG setting)

endif

endif



ifeq ($(BR2_PACKAGE_LINUX_BACKPORTS_USE_CUSTOM_CONFIG),y)

ifeq ($(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE)),)

$(error No linux-backports configuration file specified, check your BR2_PACKAGE_LINUX_BACKPORTS_CUSTOM_CONFIG_FILE setting)

endif

endif



endif # BR_BUILDING



$(eval $(kconfig-package))



# linux-backports' own .config file needs options from the kernel's own

# .config file. The dependencies handling in the infrastructure does not

# allow to express this kind of dependencies. Besides, linux.mk might

# not have been parsed yet, so the Linux build dir LINUX_DIR is not yet

# known. Thus, we use a "secondary expansion" so the rule is re-evaluated

# after all Makefiles are parsed, and thus at that time we will have the

# LINUX_DIR variable set to the proper value.

#

# Furthermore, we want to check the kernel version, since linux-backports

# only supports kernels >= 3.0. To avoid overriding linux-backports'

# .config rule defined in the kconfig-package infra, we use an

# intermediate stamp-file.

#

# Finally, it must also come after the call to kconfig-package, so we get

# LINUX_BACKPORTS_DIR properly defined (because the target part of the

# rule is not re-evaluated).

#

$(LINUX_BACKPORTS_DIR)/.config: $(LINUX_BACKPORTS_DIR)/.stamp_check_kernel_version



.SECONDEXPANSION:

$(LINUX_BACKPORTS_DIR)/.stamp_check_kernel_version: $$(LINUX_DIR)/.config

	$(Q)LINUX_VERSION_PROBED=$(LINUX_VERSION_PROBED); \

	if [ $${LINUX_VERSION_PROBED%%.*} -lt 3 ]; then \

		printf "Linux version '%s' is too old for linux-backports (needs 3.0 or later)\n" \

			"$${LINUX_VERSION_PROBED}"; \

		exit 1; \

	fi

	$(Q)touch $(@)