From 88878c7dfb04e69b75f1518fe809b917095a33b8 Mon Sep 17 00:00:00 2001
From: P J P <prasad@redhat.com>
Date: Sun, 15 Sep 2013 13:37:43 +0530
Subject: [PATCH 2/2] Export initial ramdisk compression config option

Make menuconfig allows one to choose compression format of an
initial ramdisk image. But this choice does not result in duly
compressed ramdisk image. Because - $ make install - does not
pass on the selected compression choice to the dracut(8) tool,
which creates the initramfs file. dracut(8) generates the image
with the default compression, ie. gzip(1).

This patch exports the selected compression option to a sub-shell
environment, so that it could be used by dracut(8) tool to generate
appropriately compressed initramfs images.

There isn't a straight forward way to pass on options to dracut(8)
via positional parameters. Because it is indirectly invoked at the
end of a $ make install sequence.

 # make install
   -> arch/$arch/boot/Makefile
    -> arch/$arch/boot/install.sh
     -> /sbing/installkernel ...
      -> /sbin/new-kernel-pkg ...
       -> /sbin/dracut ...

Signed-off-by: P J P <prasad@redhat.com>

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 41250fb..9f4cdf1d 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -11,6 +11,23 @@ else
         KBUILD_DEFCONFIG := $(ARCH)_defconfig
 endif
 
+# Select initial ramdisk compression format, default is gzip(1).
+# This shall be used by the dracut(8) tool while creating an initramfs image.
+#
+INITRD_COMPRESS=gzip
+ifeq ($(CONFIG_RD_BZIP2), y)
+        INITRD_COMPRESS=bzip2
+else ifeq ($(CONFIG_RD_LZMA), y)
+        INITRD_COMPRESS=lzma
+else ifeq ($(CONFIG_RD_XZ), y)
+        INITRD_COMPRESS=xz
+else ifeq ($(CONFIG_RD_LZO), y)
+        INITRD_COMPRESS=lzo
+else ifeq ($(CONFIG_RD_LZ4), y)
+        INITRD_COMPRESS=lz4
+endif
+export INITRD_COMPRESS
+
 # BITS is used as extension for files which are available in a 32 bit
 # and a 64 bit version to simplify shared Makefiles.
 # e.g.: obj-y += foo_$(BITS).o
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index 76faec1..b3d6c38 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -57,6 +57,11 @@ static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
  *	cramfs
  *	squashfs
  *	gzip
+ *	bzip2
+ *	lzma
+ *	xz
+ *	lzo
+ *	lz4
  */
 static int __init
 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
-- 
1.8.3.1