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linux/scripts/xz_wrap.sh

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decompressors: add XZ decompressor module In userspace, the .lzma format has become mostly a legacy file format that got superseded by the .xz format. Similarly, LZMA Utils was superseded by XZ Utils. These patches add support for XZ decompression into the kernel. Most of the code is as is from XZ Embedded <http://tukaani.org/xz/embedded.html>. It was written for the Linux kernel but is usable in other projects too. Advantages of XZ over the current LZMA code in the kernel: - Nice API that can be used by other kernel modules; it's not limited to kernel, initramfs, and initrd decompression. - Integrity check support (CRC32) - BCJ filters improve compression of executable code on certain architectures. These together with LZMA2 can produce a few percent smaller kernel or Squashfs images than plain LZMA without making the decompression slower. This patch: Add the main decompression code (xz_dec), testing module (xz_dec_test), wrapper script (xz_wrap.sh) for the xz command line tool, and documentation. The xz_dec module is enough to have a usable XZ decompressor e.g. for Squashfs. 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>
2011-01-12 18:01:22 -07:00
#!/bin/sh
#
# This is a wrapper for xz to compress the kernel image using appropriate
# compression options depending on the architecture.
#
# Author: Lasse Collin <lasse.collin@tukaani.org>
#
# This file has been put into the public domain.
# You can do whatever you want with this file.
#
BCJ=
LZMA2OPTS=
xz: Enable BCJ filters on SPARC and 32-bit x86 The BCJ filters were meant to be enabled already on these archs, but the xz_wrap.sh script was buggy. Enabling the filters should give smaller kernel images. xz_wrap.sh will now use $SRCARCH instead of $ARCH to detect the architecture. That way it doesn't need to care about the subarchs (like i386 vs. x86_64) since the BCJ filters don't care either. Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Acked-by: Jan Beulich <jbeulich@suse.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-18 09:55:44 -07:00
case $SRCARCH in
x86) BCJ=--x86 ;;
decompressors: add XZ decompressor module In userspace, the .lzma format has become mostly a legacy file format that got superseded by the .xz format. Similarly, LZMA Utils was superseded by XZ Utils. These patches add support for XZ decompression into the kernel. Most of the code is as is from XZ Embedded <http://tukaani.org/xz/embedded.html>. It was written for the Linux kernel but is usable in other projects too. Advantages of XZ over the current LZMA code in the kernel: - Nice API that can be used by other kernel modules; it's not limited to kernel, initramfs, and initrd decompression. - Integrity check support (CRC32) - BCJ filters improve compression of executable code on certain architectures. These together with LZMA2 can produce a few percent smaller kernel or Squashfs images than plain LZMA without making the decompression slower. This patch: Add the main decompression code (xz_dec), testing module (xz_dec_test), wrapper script (xz_wrap.sh) for the xz command line tool, and documentation. The xz_dec module is enough to have a usable XZ decompressor e.g. for Squashfs. 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>
2011-01-12 18:01:22 -07:00
powerpc) BCJ=--powerpc ;;
ia64) BCJ=--ia64; LZMA2OPTS=pb=4 ;;
arm) BCJ=--arm ;;
sparc) BCJ=--sparc ;;
esac
exec xz --check=crc32 $BCJ --lzma2=$LZMA2OPTS,dict=32MiB
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