path: root/usr/Kconfig
diff options
authorLasse Collin <lasse.collin@tukaani.org>2011-01-12 17:01:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 08:03:25 -0800
commit3ebe12439ba7fc62e1d6ecb569b7287771716ca1 (patch)
tree65945a63ad1474489d80c8ca1fb1c1c8091fb7a2 /usr/Kconfig
parent24fa0402a9b6a537e87e38341e78b7da86486846 (diff)
decompressors: add boot-time XZ support
This implements the API defined in <linux/decompress/generic.h> which is used for kernel, initramfs, and initrd decompression. This patch together with the first patch is enough for XZ-compressed initramfs and initrd; XZ-compressed kernel will need arch-specific changes. The buffering requirements described in decompress_unxz.c are stricter than with gzip, so the relevant changes should be done to the arch-specific code when adding support for XZ-compressed kernel. Similarly, the heap size in arch-specific pre-boot code may need to be increased (30 KiB is enough). The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and memzero() (memset(ptr, 0, size)), which aren't available in all arch-specific pre-boot environments. I'm including simple versions in decompress_unxz.c, but a cleaner solution would naturally be nicer. Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: Phillip Lougher <phillip@lougher.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'usr/Kconfig')
1 files changed, 18 insertions, 0 deletions
diff --git a/usr/Kconfig b/usr/Kconfig
index c2c7fe2f717..4780deac597 100644
--- a/usr/Kconfig
+++ b/usr/Kconfig
@@ -72,6 +72,15 @@ config RD_LZMA
Support loading of a LZMA encoded initial ramdisk or cpio buffer
If unsure, say N.
+config RD_XZ
+ bool "Support initial ramdisks compressed using XZ" if EMBEDDED
+ default !EMBEDDED
+ depends on BLK_DEV_INITRD
+ help
+ Support loading of a XZ encoded initial ramdisk or cpio buffer.
+ If unsure, say N.
config RD_LZO
bool "Support initial ramdisks compressed using LZO" if EMBEDDED
default !EMBEDDED
@@ -139,6 +148,15 @@ config INITRAMFS_COMPRESSION_LZMA
three. Compression is slowest. The initramfs size is about 33%
smaller with LZMA in comparison to gzip.
+ bool "XZ"
+ depends on RD_XZ
+ help
+ XZ uses the LZMA2 algorithm. The initramfs size is about 30%
+ smaller with XZ in comparison to gzip. Decompression speed
+ is better than that of bzip2 but worse than gzip and LZO.
+ Compression is slow.
bool "LZO"
depends on RD_LZO