lib: add support for LZ4-compressed kernel

Add support for extracting LZ4-compressed kernel images, as well as
LZ4-compressed ramdisk images in the kernel boot process.

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/usr/Kconfig b/usr/Kconfig
index 085872bb2bb5..642f503d3e9f 100644
--- a/usr/Kconfig
+++ b/usr/Kconfig
@@ -90,6 +90,15 @@ config RD_LZO
           Support loading of a LZO encoded initial ramdisk or cpio buffer
           If unsure, say N.
 
+config RD_LZ4
+        bool "Support initial ramdisks compressed using LZ4" if EXPERT
+        default !EXPERT
+        depends on BLK_DEV_INITRD
+        select DECOMPRESS_LZ4
+        help
+          Support loading of a LZ4 encoded initial ramdisk or cpio buffer
+          If unsure, say N.
+
 choice
         prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!=""
         help