[Buildroot] [PATCH v2 2/3] aufs: new kernel extension

[Yann E. MORIN <yann.morin.1998@free.fr>]

Atul, Christian, All,

On 2016-04-29 19:01 +0530, Atul Singh spake thusly:
> From: Christian Stewart <christian@paral.in>
> 
> Adding a kernel extension that patches the kernel with the correct
> version of aufs-standalone. This relies on the user ensuring the
> correct version is set in the configs.
> 
> Signed-off-by: Christian Stewart <christian@paral.in>
> [Atul:
>  - Removed the depends on.
>  - Changed the name of the variable BR2_PACKAGE_AUFS_STANDALONE_VERSION.
>  - Removed the comment  "aufs needs a toolchain w/ threads".
>  - Removed the choice BR2_PACKAGE_AUFS_3X or BR2_PACKAGE_AUFS_4X.
>  - Default left to empty rather than some text.
>  - Used AUFS_DIR instead of AUFS_SRCDIR.
>  - Used $(@D) instead of $(LINUX_DIR).
> ]
> Signed-off-by: Atul Singh <atul.singh.mandla@rockwellcollins.com>
> ---
>  linux/Config.ext.in     | 28 ++++++++++++++++++++++++++++
>  linux/linux-ext-aufs.mk | 23 +++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
>  create mode 100644 linux/linux-ext-aufs.mk
> 
> diff --git a/linux/Config.ext.in b/linux/Config.ext.in
> index 755c23b..7fa1156 100644
> --- a/linux/Config.ext.in
> +++ b/linux/Config.ext.in
> @@ -64,4 +64,32 @@ config BR2_LINUX_KERNEL_EXT_FBTFT
>  
>  	  https://github.com/notro/fbtft
>  
> +# aufs-standalone
> +config BR2_LINUX_KERNEL_EXT_AUFS
> +	bool "Aufs Filesystem Module patch"
> +	select BR2_PACKAGE_AUFS
> +	help
> +	  Aufs is split in two parts: a kernel part and a userspace
> +	  part. Enabling this option automatically selects the aufs
> +	  standalone (module) package and patches the Linux kernel
> +	  built by Buildroot with the aufs kernel part (ie fs/aufs).
> +
> +	  It is important to use the correct branch of aufs-standalone.
> +
> +if BR2_LINUX_KERNEL_EXT_AUFS

When there is a single option, we don;t use an if statement, but...

> +config BR2_LINUX_KERNEL_EXT_AUFS_VERSION
> +	string "aufs-standalone branch"

... jsut a depends on statement here:

    depends on BR2_LINUX_KERNEL_EXT_AUFS

> +	default ""
> +	help
> +	  Aufs-standalone repository branch must be selected and
> +	  must match the current kernel version.  Review the
> +	  following pages to determine what branch number is valid
> +	  depending on which major version that was selected.

I'm not sure this is very explicit. What about:

    Select the aufs-standalone branch to use, without the leading
    'aufs' part (i.e. just the version).

    Note that the version you choose must match that of your kernel.
    See the following resources to see what versions are available:

> +	  https://sourceforge.net/p/aufs/aufs3-standalone/ref/master/branches/
> +	  https://github.com/sfjro/aufs4-standalone/branches/all
> +
> +endif
> +
>  endmenu
> diff --git a/linux/linux-ext-aufs.mk b/linux/linux-ext-aufs.mk
> new file mode 100644
> index 0000000..7d48745
> --- /dev/null
> +++ b/linux/linux-ext-aufs.mk
> @@ -0,0 +1,23 @@
> +################################################################################
> +# Linux Aufs extensions
> +#
> +# Patch the linux kernel with aufs extension
> +################################################################################
> +
> +LINUX_EXTENSIONS += aufs
> +
> +define AUFS_PREPARE_KERNEL
> +	if test -d $(@D)/fs/aufs/; then \
> +		echo "Your kernel already supports AUFS. Not patching."; \

We want to consider this an error, so you must also "exit 1;" here.

> +	else \
> +		$(APPLY_PATCHES) $(@D) $(AUFS_DIR) \
> +			$(AUFS_MAJOR_VERSION)-kbuild.patch \
> +			$(AUFS_MAJOR_VERSION)-base.patch \
> +			$(AUFS_MAJOR_VERSION)-mmap.patch \
> +			$(AUFS_MAJOR_VERSION)-standalone.patch ; \
> +	fi
> +	cp $(AUFS_DIR)/Documentation/ABI/testing/* $(@D)/Documentation/ABI/testing/
> +	cp -r $(AUFS_DIR)/Documentation/filesystems/aufs/ $(@D)/Documentation/filesystems/aufs/

We don't care much about the documentation for the build, don't copy it.
The user can still see it in $(AUFS_DIR).

Regards,
Yann E. MORIN.

> +	cp -r $(AUFS_DIR)/fs/aufs/ $(@D)/fs/
> +	cp $(AUFS_DIR)/include/uapi/linux/aufs_type.h $(@D)/include/uapi/linux/
> +endef
> -- 
> 2.5.0
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'