Add LZO compression support for initramfs and old-style initrd

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Tested-by: Wu Zhangjin <wuzhangjin@gmail.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Russell King <rmk@arm.linux.org.uk>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Albin Tonnerre 2010-01-08 14:42:46 -08:00 committed by Linus Torvalds
parent 13510997d6
commit cacb246f8d
4 changed files with 31 additions and 5 deletions

View File

@ -117,6 +117,10 @@ config DECOMPRESS_BZIP2
config DECOMPRESS_LZMA
tristate
config DECOMPRESS_LZO
select LZO_DECOMPRESS
tristate
#
# Generic allocator support is selected if needed
#

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@ -69,6 +69,7 @@ obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o
obj-$(CONFIG_TEXTSEARCH) += textsearch.o
obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o

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@ -9,6 +9,7 @@
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/types.h>
#include <linux/string.h>
@ -22,6 +23,9 @@
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif
static const struct compress_format {
unsigned char magic[2];
@ -32,6 +36,7 @@ static const struct compress_format {
{ {037, 0236}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
{ {0x89, 0x4c}, "lzo", unlzo },
{ {0, 0}, NULL, NULL }
};

View File

@ -72,6 +72,15 @@ config RD_LZMA
Support loading of a LZMA encoded initial ramdisk or cpio buffer
If unsure, say N.
config RD_LZO
bool "Support initial ramdisks compressed using LZO" if EMBEDDED
default !EMBEDDED
depends on BLK_DEV_INITRD
select DECOMPRESS_LZO
help
Support loading of a LZO encoded initial ramdisk or cpio buffer
If unsure, say N.
choice
prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!=""
help
@ -108,16 +117,15 @@ config INITRAMFS_COMPRESSION_GZIP
bool "Gzip"
depends on RD_GZIP
help
The old and tried gzip compression. Its compression ratio is
the poorest among the 3 choices; however its speed (both
compression and decompression) is the fastest.
The old and tried gzip compression. It provides a good balance
between compression ratio and decompression speed.
config INITRAMFS_COMPRESSION_BZIP2
bool "Bzip2"
depends on RD_BZIP2
help
Its compression ratio and speed is intermediate.
Decompression speed is slowest among the three. The initramfs
Decompression speed is slowest among the four. The initramfs
size is about 10% smaller with bzip2, in comparison to gzip.
Bzip2 uses a large amount of memory. For modern kernels you
will need at least 8MB RAM or more for booting.
@ -128,7 +136,15 @@ config INITRAMFS_COMPRESSION_LZMA
help
The most recent compression algorithm.
Its ratio is best, decompression speed is between the other
two. Compression is slowest. The initramfs size is about 33%
three. Compression is slowest. The initramfs size is about 33%
smaller with LZMA in comparison to gzip.
config INITRAMFS_COMPRESSION_LZO
bool "LZO"
depends on RD_LZO
help
Its compression ratio is the poorest among the four. The kernel
size is about about 10% bigger than gzip; however its speed
(both compression and decompression) is the fastest.
endchoice