[Buildroot] [PATCH 1/2 v9] package/linux-backports: new package

[Romain Naour <romain.naour@openwide.fr>]

Hi Yann, all

Le 23/07/2015 23:55, Yann E. MORIN a ?crit :
> From: Petr Vorel <petr.vorel@gmail.com>
> 
> 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
							      will be
> 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>
> 

I've only tested linux-backports package with patch 2/2.

Reviewed-by: Romain Naour <romain.naour@openwide.fr>

Best regards,
Romain

> ---
> Changes v8 -> v9:
>   - better depend on the Linux .config  (Thomas)
> 
> Changes v7 -> v8:  (Yann)
>   - fix option ordering and prompts in Config.in
>   - drop editors, only menuconfig is available
>   - add licensing information
>   - bump to 4.1.1-1, drop 4.0.1-1 patch
>   - move custom error message before call to kconfig-package
>   - use $(BR_BUILDING) instead of custom, wrong test on 'make source'
>   - drop intermediate variable to set LINUX_BACKPORTS_KCONFIG_FILE
>   - qstrip all variables from Config.in
>   - fix dependencies (tricky, needs kernel to be configured)
>   - check kernel is >= 3.0
> 
> Changes v6->v7:
> * Bump version to lastest stable 4.0.1-1.
> * Update to current version of kconfig-package.
> * Add option to specify config fragments.
> * Include upstream patch to fix build error.
> 
> Changes v5->v6:
> Added changes by Arnout Vandecappelle in Mon Apr 20 21:46:34 UTC 2015:
> * linux-backports.mk: $(LINUX_BACKPORTS_KCONFIG_FILE): linux
>   this doesn't help: we'd need to use:
>   LINUX_BACKPORTS_KCONFIG_FILE := $(LINUX_BACKPORTS_DIR)/defconfigs/$(call qstrip,$(BR2_PACKAGE_LINUX_BACKPORTS_DEFCONFIG))
>   but then we don't get value for $(LINUX_BACKPORTS_DIR) nor $(@D).
> * linux-backports.mk: LINUX_BACKPORTS_PATCH_DEPENDENCIES = linux
>   This also does not help, it does linux extracting, patching, but we
>   need also configuring. We'd need something like
>   LINUX_BACKPORTS_CONFIGURE_DEPENDENCIES to be implemented.
> * Config.in: info about support from kernel 3.0.
> * Config.in: help text wrapped to 72 columns.
> 
> Changes v4->v5:
> * Added changes made by Thomas Petazzoni in Sun, 19 Apr 2015 11:03:26 +0200.
> 
> Changes v3->v4:
> * Define LINUX_BACKPORTS_MAKE_ENV instead of LINUX_BACKPORTS_MAKE_OPTS, remove TARGET_MAKE_ENV from it.
> * Add nconfig to LINUX_BACKPORTS_KCONFIG_EDITORS.
> * Clean formating of build commands.
> ---
>  package/Config.in                            |  1 +
>  package/linux-backports/Config.in            | 52 +++++++++++++++++
>  package/linux-backports/linux-backports.hash |  2 +
>  package/linux-backports/linux-backports.mk   | 87 ++++++++++++++++++++++++++++
>  4 files changed, 142 insertions(+)
>  create mode 100644 package/linux-backports/Config.in
>  create mode 100644 package/linux-backports/linux-backports.hash
>  create mode 100644 package/linux-backports/linux-backports.mk
> 
> diff --git a/package/Config.in b/package/Config.in
> index cfa7512..fb4df5e 100644
> --- a/package/Config.in
> +++ b/package/Config.in
> @@ -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"
> diff --git a/package/linux-backports/Config.in b/package/linux-backports/Config.in
> new file mode 100644
> index 0000000..e858a45
> --- /dev/null
> +++ b/package/linux-backports/Config.in
> @@ -0,0 +1,52 @@
> +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
> diff --git a/package/linux-backports/linux-backports.hash b/package/linux-backports/linux-backports.hash
> new file mode 100644
> index 0000000..0d41067
> --- /dev/null
> +++ b/package/linux-backports/linux-backports.hash
> @@ -0,0 +1,2 @@
> +# 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
> diff --git a/package/linux-backports/linux-backports.mk b/package/linux-backports/linux-backports.mk
> new file mode 100644
> index 0000000..e4ac9f4
> --- /dev/null
> +++ b/package/linux-backports/linux-backports.mk
> @@ -0,0 +1,87 @@
> +################################################################################
> +#
> +# 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 $(@)
>