[Buildroot] [PATCH 1/1] build host lz4 to support lz4 compression in the kernel.

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Sagaert Johan,

On Wed,  1 Apr 2015 12:30:57 +0200, Sagaert Johan wrote:

> diff --git a/linux/linux.mk b/linux/linux.mk
> index 22fce35..137c64d 100644
> --- a/linux/linux.mk
> +++ b/linux/linux.mk
> @@ -49,7 +49,7 @@ LINUX_PATCHES = $(call qstrip,$(BR2_LINUX_KERNEL_PATCH))
>  LINUX_PATCH = $(filter ftp://% http://% https://%,$(LINUX_PATCHES))
>  
>  LINUX_INSTALL_IMAGES = YES
> -LINUX_DEPENDENCIES += host-kmod host-lzop
> +LINUX_DEPENDENCIES += host-kmod host-lzop host-lz4

I think it's time to add some Config.in options in linux/Config.in to
select the compression tools to be made available, and enforce their
usage/availability in the Linux .config file. It is annoying to bvuild
host-lzop and host-lz4 every time you're building a kernel if you don't
care about those compressions algos.

> diff --git a/package/lz4/host-lz4.mk b/package/lz4/host-lz4.mk
> new file mode 100644
> index 0000000..03138f9
> --- /dev/null
> +++ b/package/lz4/host-lz4.mk
> @@ -0,0 +1,21 @@
> +################################################################################
> +#
> +# host-lz4
> +#
> +################################################################################
> +
> +HOST_LZ4_VERSION = r123
> +HOST_LZ4_SITE = $(call github,Cyan4973,lz4,$(HOST_LZ4_VERSION))
> +HOST_LZ4_LICENSE = BSD-2c
> +HOST_LZ4_LICENSE_FILES = LICENSE
> +
> +define HOST_LZ4_BUILD_CMDS
> +	$(MAKE) $(HOST_CONFIGURE_OPTS) -C $(@D)
> +endef
> +
> +define HOST_LZ4_INSTALL_CMDS
> +	$(MAKE) $(HOST_CONFIGURE_OPTS) -C $(@D) install DESTDIR=$(HOST_DIR)
> +endef
> +
> +$(eval $(host-generic-package))
> +
> diff --git a/package/lz4/lz4.mk b/package/lz4/lz4.mk
> index 38e10d8..6f8af03 100644
> --- a/package/lz4/lz4.mk
> +++ b/package/lz4/lz4.mk
> @@ -17,14 +17,6 @@ endef
>  LZ4_POST_PATCH_HOOKS += LZ4_DISABLE_SHARED
>  endif
>  
> -define HOST_LZ4_BUILD_CMDS
> -	$(MAKE) $(HOST_CONFIGURE_OPTS) -C $(@D)
> -endef
> -
> -define HOST_LZ4_INSTALL_CMDS
> -	$(MAKE) $(HOST_CONFIGURE_OPTS) -C $(@D) install DESTDIR=$(HOST_DIR)
> -endef
> -
>  define LZ4_BUILD_CMDS
>  	$(MAKE) $(TARGET_CONFIGURE_OPTS) -C $(@D) liblz4
>  endef
> @@ -38,4 +30,3 @@ define LZ4_INSTALL_TARGET_CMDS
>  endef
>  
>  $(eval $(generic-package))
> -$(eval $(host-generic-package))

This entire change seems completely unnecessary, and not only that, but
it is completely incompatible with the Buildroot best practices to
write host packages. Why did you do this change in the first place?

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com