- WIMLIB
-
-This is wimlib version 1.2.2 (December 2012). wimlib can be used to read,
-write, and mount files in the Windows Imaging Format (WIM files). These files
-are normally created by using the `imagex.exe' utility on Windows, but this
-library provides a free implementation of imagex for UNIX-based systems.
-
- WIM FILES
-
-A Windows Imaging (WIM) file is an archive. Like some other archive formats
-such as ZIP, files in WIM archives may be compressed. WIM archives support two
-Microsoft-specific compression formats: LZX and XPRESS. Both are based on LZ77
-and Huffman encoding, and both are supported by wimlib.
-
-Unlike ZIP files, WIM files can contain multiple independent toplevel directory
-trees known as images. While each image has its own metadata describing a
-directory tree and file access modes, files are not duplicated for each image;
-instead, each file is included only once in the entire WIM. Microsoft did this
-so that in one WIM file, they could do things like have 5 different versions of
-Windows that are almost exactly the same.
-
-Microsoft provides documentation for the WIM file format, XPRESS compression
-format, and LZX compression format. The XPRESS documentation is acceptable, but
-the LZX documentation is not entirely correct, and the WIM documentation itself
-is incomplete.
-
-A WIM file may be either stand-alone or split into multiple parts.
-
- PROGRAMS
-
-wimlib provides a public API for other programs to use, but also comes with two
-programs: `imagex' and `mkwinpeimg'.
-
-`imagex' is intended to be like the imagex.exe program from Windows. `imagex'
-can be used to create, extract, and mount WIM files. Both read-only and
-read-write mounts are supported. See the man page `doc/imagex.1' for more
-details.
-
-`mkwinpeimg' is shell script that makes it easy to create a customized bootable
-image of Windows PE that can be put on a CD or USB drive, or published on a
-server for PXE booting. See the main page `doc/mkwinpeimg.1' for more details.
-
-There is an additional program, `wimapply', that is not installed by default.
-It can be used to build a small executable with the ability to apply a WIM image
-from a standalone WIM, without having to build the whole shared library. This
-could be useful on Linux boot clients that only need to be able to apply a WIM,
-not capture/split/join/append/export/mount a WIM. See `programs/wimapply.c'.
-
- COMPRESSION RATIO
-
-wimlib can create XPRESS or LZX compressed WIM archives. Currently, the XPRESS
-compression ratio is slightly better than that provided by Microsoft's software,
-while the LZX compression ratio is approaching that of Microsoft's software but
-is not quite there yet. Running time is as good as or better than Microsoft's
-software, especially with multithreaded compression, available in wimlib v1.1.0
-and later.
-
+ INTRODUCTION
+
+This is wimlib version 1.5.3 (December 2013). wimlib is a C library for
+creating, modifying, extracting, and mounting files in the Windows Imaging
+Format (WIM files). These files are normally created using the ImageX
+(imagex.exe) or Dism (Dism.exe) utilities on Windows, but wimlib is distributed
+with a free implementation of ImageX called "wimlib-imagex" for both UNIX-like
+systems and Windows.
+
+ INSTALLATION
+
+To install wimlib and wimlib-imagex on Windows you simply need to download and
+extract the ZIP file containing the latest binaries from the SourceForge page
+(http://sourceforge.net/projects/wimlib/), which you may have already done.
+
+To install wimlib and wimlib-imagex on UNIX-like systems (with Linux being the
+primary supported and tested platform), you must compile the source code, which
+is also available at http://sourceforge.net/projects/wimlib/. Alternatively,
+check if a package has been prepared for your Linux distribution. Example files
+for Debian and RPM packaging are in the debian/ and rpm/ directories.
+
+ WIM FILES
+
+A Windows Imaging (WIM) file is an archive designed primarily for archiving
+Windows filesystems. However, it can be used on other platforms as well, with
+some limitations. Like some other archive formats such as ZIP, files in WIM
+archives may be compressed. WIM files support two compression formats: LZX and
+XPRESS *. Both are supported by wimlib.
+
+A WIM file consists of one or more "images". Each image is an independent
+top-level directory structure and is logically separate from all other images in
+the WIM. Each image has a name as well as a 1-based index in the WIM file. To
+save space, WIM archives automatically combine all duplicate files across all
+images.
+
+A WIM file may be either stand-alone or split into multiple parts. Split WIMs
+are read-only and cannot be modified.
+
+* Note: The Windows 8 WIMGAPI apparently adds a third format, LZMS, but it is
+ not documented and is incompatible with ImageX and Dism. It is unclear if
+ this new format is actually being used for anything.
+
+ IMAGEX IMPLEMENTATION
+
+wimlib itself is a C library, and it provides a documented public API (See:
+http://wimlib.sourceforge.net) for other programs to use. However, it is also
+distributed with a command-line program called "wimlib-imagex" that uses this
+library to implement an imaging tool similar to Microsoft's ImageX.
+wimlib-imagex supports almost all the capabilities of Microsoft's ImageX as well
+as additional capabilities. wimlib-imagex works on both UNIX-like systems and
+Windows, although some features differ between the platforms.
+
+Run `wimlib-imagex' with no arguments to see an overview of the available
+commands and their syntax. For additional documentation:
+
+ * If you have installed wimlib-imagex on a UNIX-like system, you will find
+ further documentation in the man pages; run `man wimlib-imagex' to get
+ started.
+
+ * If you have downloaded the Windows binary distribution, you will find the
+ documentation for wimlib-imagex in PDF format in the "doc" directory,
+ ready for viewing with any PDF viewer. Please note that although the PDF
+ files are converted from UNIX-style "man pages", they do document
+ Windows-specific behavior when appropriate.
+
+ COMPRESSION RATIO
+
+wimlib (and wimlib-imagex) can create XPRESS or LZX compressed WIM archives.
The following tables compare the compression ratio and performance for creating
-a compressed Windows PE image (disk usage of about 524 MB, uncompressed WIM size
-361 MB):
-
- Table 1. WIM size
-
- XPRESS Compression LZX Compression
- wimlib imagex (v1.2.1): 138,971,353 bytes 131,379,943 bytes
- Microsoft imagex.exe: 140,406,981 bytes 127,249,176 bytes
-
- Table 2. Time to create WIM
-
- XPRESS Compression LZX Compression
- wimlib imagex (v1.2.1, 2 threads): 11 sec 17 sec
- Microsoft imagex.exe: 25 sec 89 sec
-
- NTFS SUPPORT
-
-As of version 1.0.0, wimlib supports capturing and applying images directly to
-NTFS volumes. This was made possible with the help of libntfs-3g from the
-NTFS-3g project. This feature supports capturing and restoring NTFS-specific
-data such as security descriptors, alternate data streams, and reparse point
-data.
-
-The code for NTFS image capture and image application is complete enough that it
-is possible to apply an image from the "install.wim" contained in recent Windows
-installation media (Vista, Windows 7, or Windows 8) directly to a NTFS volume,
-and then boot Windows from it after preparing the Boot Configuration Data. In
-addition, a Windows installation can be captured (or backed up) into a WIM file,
-and then re-applied later.
-
- WINDOWS PE
-
-A major use for this library is to create customized images of Windows PE, the
-Windows Preinstallation Environment, without having to rely on Windows. Windows
-PE is a lightweight version of Windows that can run entirely from memory and can
-be used to install Windows from local media or a network drive or perform
-maintenance. Windows PE is the operating system that runs when you boot from
+a compressed x86_64 Windows PE image. Note: these timings were done on Windows
+so that the times would be fully comparable; however, wimlib may have even
+better performance on other operating systems such as Linux. Timings were done
+with 2 CPUs available, both of which automatically are used by wimlib for both
+XPRESS and LZX, and also by imagex.exe but apparently only for LZX.
+
+ Table 1. WIM size
+
+ XPRESS Compression LZX Compression
+ wimlib-imagex (v1.5.3): 207,444,390 bytes 188,106,091 bytes
+ Microsoft imagex.exe (Windows 7): 209,960,209 bytes 188,224,481 bytes
+
+ Table 2. Time to create WIM
+
+ XPRESS Compression LZX Compression
+ wimlib-imagex (v1.5.3): 73 sec 202 sec
+ Microsoft imagex.exe (Windows 7): 90 sec 149 sec
+
+The above LZX data are using explicitly specified maximum compression
+('--compress=maximum') as of wimlib v1.5.3. If `wimlib-imagex capture' or
+`wimlib-imagex capture' is instead run with no '--compress' argument, then a
+faster LZX compressor is used; it will produce results in between those given
+for XPRESS and LZX above.
+
+Note: if the absolute maximum (but still compatible) compression ratio is
+desired, `wimlib-imagex optimize WIMFILE --recompress --compress-slow' on one of
+the above LZX-compressed WIMs produces a WIM of 187,089,943 bytes in about 400
+seconds.
+
+ NTFS SUPPORT
+
+WIM images may contain data, such as alternate data streams and
+compression/encryption flags, that are best represented on the NTFS filesystem
+used on Windows. Also, WIM images may contain security descriptors which are
+specific to Windows and cannot be represented on other operating systems.
+wimlib handles this NTFS-specific or Windows-specific data in a
+platform-dependent way:
+
+ * In the Windows version of wimlib and wimlib-imagex, NTFS-specific and
+ Windows-specific data are supported natively.
+
+ * In the UNIX version of wimlib and wimlib-imagex, NTFS-specific and
+ Windows-specific data are ordinarily ignored; however, there is also special
+ support for capturing and extracting images directly to/from unmounted NTFS
+ volumes. This was made possible with the help of libntfs-3g from the
+ NTFS-3g project.
+
+For both platforms the code for NTFS capture and extraction is complete enough
+that it is possible to apply an image from the "install.wim" contained in recent
+Windows installation media (Vista, Windows 7, or Windows 8) directly to a NTFS
+filesystem, and then boot Windows from it after preparing the Boot Configuration
+Data. In addition, a Windows installation can be captured (or backed up) into a
+WIM file, and then re-applied later.
+
+ WINDOWS PE
+
+A major use for wimlib and wimlib-imagex is to create customized images of
+Windows PE, the Windows Preinstallation Environment, on either UNIX-like systems
+or Windows without having to rely on Microsoft's software and its restrictions
+and limitations.
+
+Windows PE is a lightweight version of Windows that can run entirely from memory
+and can be used to install Windows from local media or a network drive or
+perform maintenance. It is the operating system that runs when you boot from
the Windows installation media.
You can find Windows PE on the installation DVD for Windows Vista, Windows 7, or
Windows 8, in the file `sources/boot.wim'. Windows PE can also be found in the
Windows Automated Installation Kit (WAIK), which is free to download from
-Microsoft, inside the `WinPE.cab' file, which you can extract if you install
-either the `cabextract' or `p7zip' programs.
+Microsoft, inside the `WinPE.cab' file, which you can extract natively on
+Windows, or on UNIX-like systems if you install either the `cabextract' or
+`p7zip' programs.
In addition, Windows installations and recovery partitions frequently contain a
WIM containing an image of the Windows Recovery Environment, which is similar to
Windows PE.
- DEPENDENCIES
+A shell script `mkwinpeimg' is distributed with wimlib on UNIX-like systems to
+ease the process of creating and customizing a bootable Windows PE image.
+
+ DEPENDENCIES
+
+This section documents the dependencies of wimlib and the programs distributed
+with it, when building for a UNIX-like system from source. If you have
+downloaded the Windows binary distribution of wimlib and wimlib-imagex then all
+dependencies were already included and this section is irrelevant.
* libxml2 (required)
This is a commonly used free library to read and write XML files. You
* libfuse (optional but highly recommended)
Unless configured with --without-fuse, wimlib requires a non-ancient
- version of libfuse to be installed. Most GNU/Linux distributions
- already include this, but make sure you have the libfuse package
- installed, and also libfuse-dev if your distribution distributes header
- files separately. FUSE also requires a kernel module. If the kernel
- module is available it will automatically be loaded if you try to mount
- a WIM file. For more information see http://fuse.sourceforge.net/.
- FUSE is also available for FreeBSD.
+ version of libfuse to be installed. Most Linux distributions already
+ include this, but make sure you have the libfuse package installed, and
+ also libfuse-dev if your distribution distributes header files
+ separately. FUSE also requires a kernel module. If the kernel module
+ is available it will automatically be loaded if you try to mount a WIM
+ file. For more information see http://fuse.sourceforge.net/. FUSE is
+ also available for FreeBSD.
* libntfs-3g (optional but highly recommended)
Unless configured with --without-ntfs-3g, wimlib requires the library
and headers for libntfs-3g version 2011-4-12 or later to be installed.
Versions dated 2010-3-6 and earlier do not work because they are missing
the header xattrs.h (and the file xattrs.c, which contains functions we
- need).
+ need). libntfs-3g version 2013-1-13 is compatible only with wimlib
+ 1.2.4 and later.
* OpenSSL / libcrypto (optional)
wimlib can use the SHA1 message digest code from OpenSSL instead of
- compiling in yet another SHA1 implementation. (See LICENSE section.)
+ compiling in yet another SHA1 implementation. (See LICENSE section.)
* cdrkit (optional)
* mtools (optional)
* syslinux (optional)
* cabextract (optional)
The `mkwinpeimg' shell script will look for several other programs
- depending on what options are given to it. Depending on your GNU/Linux
+ depending on what options are given to it. Depending on your Linux
distribution, you may already have these programs installed, or they may
be in the software repository. Making an ISO filesystem requires
`mkisofs' from `cdrkit' (http://www.cdrkit.org). Making a disk image
(http://www.syslinux.org). Retrieving files from the Windows Automated
Installation Kit requires `cabextract' (http://www.cabextract.org.uk).
- CONFIGURATION
+ CONFIGURATION
-Besides the various well-known options, the following options can be passed to
-wimlib's `configure' script:
+This section documents the most important options that may be passed to the
+"configure" script when building from source:
--without-ntfs-3g
If libntfs-3g is not available or is not version 2011-4-12 or later,
Use a very fast assembly language implementation of SHA1 from Intel.
Only use this if the build target supports the SSSE3 instructions.
---disable-custom-memory-allocator
- If this option is given, a very small amount of space will be saved by
- removing support for the wimlib_set_memory_allocator() function. imagex
- will be unaffected.
-
---disable-verify-compression
- Unless this option is given, every time wimlib compresses a data block,
- it will decompress it into a temporary buffer and abort the program with
- an error message if the decompressed data does not exactly match the
- original data. This only makes compression about 10% slower. However,
- this checking can probably be safely disabled because there are no known
- bugs in the compression code, and the SHA1 message digest of every
- extracted file is checked anyway.
-
--disable-error-messages
Save some space by removing all error messages from the library.
--disable-assertions
- Remove all assertions, even the ones that are included by default.
-
---enable-more-assertions
- Enable assertions that are not included by default.
+ Remove assertions included by default.
---enable-debug
- Include debugging messages. Only use this option if you have found a
- bug in the library.
+ PORTABILITY
---enable-more-debug
- Include more debugging messages. Only use this option if you have found
- a bug in the library.
-
- PORTABILITY
-
-wimlib has mostly been developed and tested on x86_64 (64-bit) GNU/Linux.
-
-It has been tested on x86 (32-bit) GNU/Linux occasionally.
+wimlib has primarily been tested on Linux and Windows (primarily Windows 7, but
+also Windows XP and Windows 8).
wimlib may work on FreeBSD and Mac OS X. However, this is not well tested. If
you do not have libntfs-3g 2011-4-12 or later available, you must configure
wimlib with --without-ntfs-3g. On FreeBSD, before mounting a WIM you need to
load the POSIX message queue module (run `kldload mqueuefs').
-The code pays attention to endianness, so it should work on big-endian
-architectures, but I've never tested this so do not expect it to work.
+The code has primarily been tested on x86 and x86_64 CPUs, but it's written to
+be portable to other architectures and I've also tested it on ARM. However,
+although the code is written to correctly deal with endianness, it has not yet
+actually been tested on a big-endian architecture.
-There are no plans to port wimlib to Windows since the programming interface on
-Windows is very different and Microsoft's imagex.exe is already available.
-
- REFERENCES
+ REFERENCES
The WIM file format is specified in a document that can be found in the
Microsoft Download Center. There is a similar document that specifies the LZX
compression format, and a document that specifies the XPRESS compression format.
However, many parts of these formats are poorly documented, and some parts have
no documentation whatsoever. Some particularly poorly documented parts of the
-formats have had comments added in various places in the library. Please see
-the code and/or ask me if you have any questions about the WIM file format as it
-exists in reality and not as it exists in Microsoft's poorly written
+formats have had comments added in various places in the library code. Please
+see the code and/or ask me if you have any questions about the WIM file format
+as it exists in reality and not as it exists in Microsoft's poorly written
documentation.
-The code in ntfs-apply.c and ntfs-capture.c uses the NTFS-3g library, which is a
-library for reading and writing to NTFS filesystems (the filesystem used by
-recent versions of Windows). See
+The code in ntfs-3g_apply.c and ntfs-3g_capture.c uses the NTFS-3g library,
+which is a library for reading and writing to NTFS filesystems (the filesystem
+used by recent versions of Windows). See
http://www.tuxera.com/community/ntfs-3g-download/ for more information.
lzx-decompress.c, the code to decompress WIM file resources that are compressed
-using LZX compression, is originally based on code from the cabextract project
-(http://www.cabextract.org.uk).
+using LZX compression, was originally based on code from the cabextract project
+(http://www.cabextract.org.uk) but has been rewritten.
lzx-compress.c, the code to compress WIM file resources using LZX compression,
-is originally based on code written by Matthew Russotto (www.russotto.net/chm/).
-
-lz77.c, the code to find LZ77 matches (used for both XPRESS and LZX compression),
-is based on code from zlib.
-
-A very limited number of other free programs can handle some parts of the WIM
-file format. 7-zip is able to extract and create WIMs (as well as files in many
-other archive formats). However, wimlib is designed specifically to handle WIM
-files and provides features previously only available in Microsoft's imagex.exe,
-such as the ability to mount WIMs read-write as well as read-only, and the
-ability to create LZX or XPRESS compressed WIMs.
-
-An earlier version of wimlib is being used to deploy Windows 7 from the Ultimate
-Deployment Appliance. For more information see
+was originally based on code written by Matthew Russotto (www.russotto.net/chm/)
+but has been rewritten.
+
+lz77.c, the code to find LZ77 matches (used for both XPRESS and LZX
+compression), is based on code from zlib but has been rewritten.
+
+A limited number of other free programs can handle some parts of the WIM
+file format:
+
+ * 7-zip is able to extract and create WIMs (as well as files in many
+ other archive formats). However, wimlib is designed specifically to handle
+ WIM files and provides features previously only available in Microsoft's
+ imagex.exe, such as the ability to mount WIMs read-write as well as
+ read-only, the ability to create LZX or XPRESS compressed WIMs, and the
+ correct handling of security descriptors and hard links.
+ * ImagePyX (https://github.com/maxpat78/ImagePyX) is a Python program that
+ provides similar capabilities to wimlib-imagex. One thing to note, though,
+ is that it does not support compression and decompression by itself, but
+ instead relies on external native code, such as the codecs from wimlib.
+
+A very early version of wimlib is being used to deploy Windows 7 from the
+Ultimate Deployment Appliance. For more information see
http://www.ultimatedeployment.org/.
-You can see the documentation about Microsoft's version of the imagex program at
+You can see the documentation about Microsoft's version of ImageX at
http://technet.microsoft.com/en-us/library/cc749447(v=ws.10).aspx, so you can
-see how it compares to the version provided by this library.
-
- GNU/Linux equivalents of WIM format
-
-What's the equivalent way to capture the filesystem of a GNU/Linux operating
-system into an archive file? You have a few options:
-
-SquashFS:
- SquashFS (http://squashfs.sourceforge.net/) provides a compressed,
- read-only filesystem for Linux, and it's probably the closest equivalent
- of the WIM format and better designed. Although you can't mount
- SquashFS read-write, when wimlib does this for WIM files it's really an
- illusion since the WIM isn't actually modified until the image is
- unmounted. Multiple top-level images in SquashFS files are not
- supported, although nothing stops you from just putting each image in a
- separate directory.
-
-FSArchiver:
- FSArchiver (http://www.fsarchiver.org/Main_Page) is not widely used, but
- it appears to have some features quite similar to the WIM format.
-
-Tar:
- The well-known tar format can usually capture a UNIX filesystem just
- fine, and compressing the tar file produces a good compression ratio
- (better than WIM, especially if using XZ compression), but there is no
- support for random access, file deduplication, multiple images per
- archive, or extended attributes.
-
-Zip:
- Zip shares some features with WIM but is not designed to store entire
- filesystems.
-
-7z:
- The 7z format has some nice features but is unfortunately not designed
- with UNIX in mind.
-
- MORE INFORMATION
-
-See the manual pages for `imagex', the manual pages for the subcommands of
-`imagex', and the manual page for `mkwinpeimg'.
+see how it compares to wimlib-imagex.
-As of version 0.5.0, wimlib's public API is documented. Doxygen is required to
-build the documentation. To build the documentation, run `configure', then
-enter the directory `doc' and run `doxygen'. The HTML documentation will be
-created in a directory named `html'.
+If you are looking for a UNIX archive format that provides features similar to
+WIM, I recommend you take a look at SquashFS (http://squashfs.sourceforge.net/).
- LICENSE
+ LICENSE
-As of version 1.0.0, wimlib is released under the GNU GPL version 3.0 or later.
-This includes the files in the `programs' directory as well as the files in the
-`src' directory.
+As of version 1.0.0, wimlib and all programs and scripts distributed with it are
+released under the GNU GPL version 3.0 or later.
wimlib is independently developed and does not contain any code, data, or files
copyrighted by Microsoft. It is not known to be affected by any patents.
-By default, wimlib will be linked to the system library "libcrypto", which
-probably will be OpenSSL. Some people believe that GPL code cannot be linked to
-OpenSSL without a linking exception. As far as I know, I cannot officially
-include a linking exception with the license of this library because several
-files could be considered derived works of LGPL code copyrighted by others. If
-you believe this to be a problem, configure with --without-libcrypto to avoid
-linking with OpenSSL. There is no difference in functionality--- there will
-just be stand-alone SHA1 message digest code built into the library.
+On UNIX-like systems, if you do not want wimlib to be dynamically linked with
+libcrypto (OpenSSL), configure with --without-libcrypto. This replaces the SHA1
+implementation with built-in code and there will be no difference in
+functionality.
- DISCLAIMER
+ DISCLAIMER
-wimlib is experimental. Use Microsoft's `imagex.exe' if you want to make sure
-your WIM files are made correctly (but beware: Microsoft's version contains some
-bugs).
+wimlib comes with no warranty whatsoever. Use Microsoft's `imagex.exe' if you
+want to make sure your WIM files are made "correctly" (but beware: Microsoft's
+version contains some bugs).
-Please submit a bug report (to ebiggers3@gmail.com) if you find a bug in wimlib.
+Please submit a bug report (to ebiggers3@gmail.com) if you find a bug in wimlib
+and/or wimlib-imagex.
-Some parts of the WIM file format are poorly documented or even completely
-undocumented, so I've just had to do the best I can to read and write WIMs that
-appear to be compatible with Microsoft's software.
+Be aware that some parts of the WIM file format are poorly documented or even
+completely undocumented, so I've just had to do the best I can to read and write
+WIMs that appear to be compatible with Microsoft's software.
git://wimlib.net / wimlib / blobdiff