Choose xz compressed tarball for linux kernel.

Prefer xz compressed tarball so some bandwidth is saved for kernel headers
and kernel itself downloads.

Signed-off-by: Raúl Sánchez Siles <rasasi78@gmail.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

linux/linux.mk

@@ -16,7 +16,7 @@ else ifeq ($(BR2_LINUX_KERNEL_CUSTOM_GIT),y)
 LINUX_SITE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL))
 LINUX_SITE_METHOD = git
 else
-LINUX_SOURCE = linux-$(LINUX_VERSION).tar.bz2
+LINUX_SOURCE = linux-$(LINUX_VERSION).tar.xz
 # In X.Y.Z, get X and Y. We replace dots and dashes by spaces in order
 # to use the $(word) function. We support versions such as 3.1,
 # 2.6.32, 2.6.32-rc1, 3.0-rc6, etc.

toolchain/kernel-headers/kernel-headers.mk

@@ -31,8 +31,8 @@ LINUX_HEADERS_SITE:=$(BR2_KERNEL_MIRROR:/=)/linux/kernel/v2.6/
 else
 LINUX_HEADERS_SITE:=$(BR2_KERNEL_MIRROR:/=)/linux/kernel/v3.x/
 endif
-LINUX_HEADERS_SOURCE:=linux-$(LINUX_HEADERS_VERSION).tar.bz2
-LINUX_HEADERS_CAT:=$(BZCAT)
+LINUX_HEADERS_SOURCE:=linux-$(LINUX_HEADERS_VERSION).tar.xz
+LINUX_HEADERS_CAT:=$(XZCAT)
 LINUX_HEADERS_UNPACK_DIR:=$(TOOLCHAIN_DIR)/linux-$(LINUX_HEADERS_VERSION)
 LINUX_HEADERS_DIR:=$(TOOLCHAIN_DIR)/linux