[Lzip-bug] Lzip patch for linux 5.4.18 and xlunzip 0.5 released

[Antonio Diaz Diaz]

I am pleased to announce the release of the lzip patch for linux 5.4.18 and 
the accompanying test tool xlunzip 0.5.

Since 2016 I maintain a patch adding lzip decompression support to the linux 
kernel. This includes support for lzip-compressed kernel image, initramfs, 
initrd, modules, and squashfs filesystems. The patch implements a linux 
module named lzip_decompress.

Lzip related components in the kernel
=====================================

The lzip_decompress module in lib/lzip_decompress.c provides a versatile 
lzip decompression function able to do buffer to buffer decompression or 
stream decompression with fill and flush callback functions. The usage of 
the function is documented in include/linux/lzip.h.

For decompressing the kernel image, initramfs, and initrd, there is a 
wrapper function in lib/decompress_lunzip.c providing the same common 
interface as the other decompress_*.c files, which is defined in 
include/linux/decompress/generic.h.

For kernel makefiles, two commands are provided in scripts/Makefile.lib for 
use with $(call if_changed). The kernel image must be compressed with $(call 
if_changed,klzip) which will append a four-byte trailer containing the size 
of the uncompressed data, which is needed by the boot code. Other things 
should be compressed with $(call if_changed,lzip).

Testing
=======

Xlunzip is a test tool for the lzip_decompress module. It is similar to 
lunzip, but it uses the lzip_decompress module as a backend. The xlunzip 
tarball contains a copy of the lzip_decompress module and can be compiled 
and tested without downloading or applying the patch to the kernel. The 
homepage of xlunzip is at http://www.nongnu.org/lzip/xlunzip.html

The patch can be downloaded from
http://download.savannah.gnu.org/releases/lzip/kernel/linux-5.4.18_lzip-1.diff.lz

Xlunzip can be downloaded from
http://download.savannah.gnu.org/releases/lzip/xlunzip/xlunzip-0.5.tar.lz

The sha256sums are:
f74b9e30086c4d91e777573c36479b9cc9aaf4650981a9a369c2374d506ac9e4 
linux-5.4.18_lzip-1.diff.lz
4e72f14c2e742634dbbd5fb71cf4e069c0f37534252a5662ab965371739f8db2 
xlunzip-0.5.tar.lz

Changes in version 0.5:

  * The lzip_decompress module has been updated to version 5.4.18.

  * Xlunzip now reports an error if a file name is empty (xlunzip -t "").

  * The words 'decompressed' and 'compressed' have been replaced with the 
shorter 'out' and 'in' in the verbose output when decompressing or testing.

  * Decompression speed has been slightly increased.

  * A compilation error with GCC 10 has been fixed. (Reported by Daniel 
Baumann).

  * The commands needed to extract files from a tar.lz archive have been 
documented in the output of '--help' and in the man page.

  * Xlunzip now compiles on DOS with DJGPP. (Patch from Robert Riebisch).

  * The configure script now accepts appending options to CFLAGS using the 
syntax 'CFLAGS+=OPTIONS'.

  * 9 new test files have been added to the testsuite.


Please send bug reports and suggestions to address@hidden


Thanks,
Antonio Diaz, lzip author and maintainer.

--
If you care about long-term archiving, please help me replace xz with lzip. 
See http://www.nongnu.org/lzip/lzip_benchmark.html#xz1
http://www.nongnu.org/lzip/manual/lzip_manual.html#Quality-assurance and
http://www.nongnu.org/lzip/xz_inadequate.html Thanks.