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| author | Lasse Collin <lasse.collin@tukaani.org> | 2011-01-13 02:01:23 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:03:25 +0100 |
| commit | 3ebe12439ba7fc62e1d6ecb569b7287771716ca1 (patch) | |
| tree | 65945a63ad1474489d80c8ca1fb1c1c8091fb7a2 /usr/Kconfig | |
| parent | decompressors: add XZ decompressor module (diff) | |
| download | linux-3ebe12439ba7fc62e1d6ecb569b7287771716ca1.tar.xz linux-3ebe12439ba7fc62e1d6ecb569b7287771716ca1.zip | |
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')
| -rw-r--r-- | usr/Kconfig | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/usr/Kconfig b/usr/Kconfig index c2c7fe2f717d..4780deac5974 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 + select DECOMPRESS_XZ + 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. +config INITRAMFS_COMPRESSION_XZ + 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. + config INITRAMFS_COMPRESSION_LZO bool "LZO" depends on RD_LZO |