3 This is wimlib version 1.4.0 (May 2013). wimlib is a C library for creating,
4 modifying, extracting, and mounting files in the Windows Imaging Format (WIM
5 files). These files are normally created by using the `imagex.exe' utility on
6 Windows, but wimlib is distributed with a free implementation of ImageX called
7 "wimlib-imagex" for both UNIX and Windows.
11 To install wimlib and wimlib-imagex on Windows you simply need to download and
12 extract the ZIP file containing the latest binaries from the SourceForge page
13 (http://sourceforge.net/projects/wimlib/), which you may have already done.
15 To install wimlib and wimlib-imagex on UNIX (with Linux being the primary
16 supported and tested platform), you must compile it from the source code. At
17 some point I might start posting RPMs and Debian packages for convenience.
21 A Windows Imaging (WIM) file is an archive designed primarily for archiving
22 Windows filesystems. However, it can be used on other platforms as well, with
23 some limitations. Like some other archive formats such as ZIP, files in WIM
24 archives may be compressed. WIM files support two compression formats: LZX and
25 XPRESS. Both are supported by wimlib.
27 A WIM file consists of one or more "images". Each image is an independent
28 top-level directory structure and is logically separate from all other images in
29 the WIM. Each image has a name as well as a 1-based index in the WIM file. To
30 save space, WIM archives automatically combine all duplicate files across all
33 A WIM file may be either stand-alone or split into multiple parts. Split WIMs
34 are read-only and cannot be modified.
38 wimlib itself is a C library, and it provides a documented public API (See:
39 http://wimlib.sourceforge.net) for other programs to use. However, it is also
40 distributed with a command-line program called "wimlib-imagex" that uses this
41 library to implement an imaging tool similar to Microsoft's ImageX.
42 wimlib-imagex supports almost all the capabilities of Microsoft's ImageX as well
43 as additional capabilities. wimlib-imagex works on both UNIX and Windows,
44 although some features differ between the platforms.
46 Run `wimlib-imagex' with no arguments to see an overview of the available
47 commands and their syntax. For additional documentation:
49 * If you have installed wimlib-imagex on UNIX, you will find further
50 documentation in the man pages; run `man wimlib-imagex' to get started.
52 * If you have downloaded the Windows binary distribution, you will find the
53 documentation for wimlib-imagex in PDF format in the "doc" directory,
54 ready for viewing with any PDF viewer. Please note that although the PDF
55 files are converted from UNIX-style "man pages", they do document
56 Windows-specific behavior when appropriate.
60 wimlib (and wimlib-imagex) can create XPRESS or LZX compressed WIM archives.
61 Currently, the XPRESS compression ratio is slightly better than that provided by
62 Microsoft's software, while the LZX compression ratio is approaching that of
63 Microsoft's software but is not quite there yet. Running time is as good as or
64 better than Microsoft's software, especially with multithreaded compression,
65 available in wimlib v1.1.0 and later.
67 The following tables compare the compression ratio and performance for creating
68 a compressed Windows PE image (disk usage of about 524 MB, uncompressed WIM size
73 XPRESS Compression LZX Compression
74 wimlib-imagex (v1.2.1): 138,971,353 bytes 131,379,943 bytes
75 Microsoft imagex.exe: 140,406,981 bytes 127,249,176 bytes
77 Table 2. Time to create WIM
79 XPRESS Compression LZX Compression
80 wimlib-imagex (v1.2.1, 2 threads): 11 sec 17 sec
81 Microsoft imagex.exe: 25 sec 89 sec
85 WIM images may contain data, such as alternate data streams and
86 compression/encryption flags, that are best represented on the NTFS filesystem
87 used on Windows. Also, WIM images may contain security descriptors which are
88 specific to Windows and cannot be represented on other operating systems.
89 wimlib handles this NTFS-specific or Windows-specific data in a
90 platform-dependent way:
92 * In the Windows version of wimlib and wimlib-imagex, NTFS-specific and
93 Windows-specific data are supported natively.
95 * In the UNIX version of wimlib and wimlib-imagex, NTFS-specific and
96 Windows-specific data are ordinarily ignored; however, there is also special
97 support for capturing and extracting images directly to/from unmounted NTFS
98 volumes. This was made possible with the help of libntfs-3g from the
101 For both platforms the code for NTFS capture and extraction is complete enough
102 that it is possible to apply an image from the "install.wim" contained in recent
103 Windows installation media (Vista, Windows 7, or Windows 8) directly to a NTFS
104 filesystem, and then boot Windows from it after preparing the Boot Configuration
105 Data. In addition, a Windows installation can be captured (or backed up) into a
106 WIM file, and then re-applied later.
110 A major use for wimlib and wimlib-imagex is to create customized images of
111 Windows PE, the Windows Preinstallation Environment, on either UNIX or Windows
112 without having to rely on Microsoft's software and its restrictions and
115 Windows PE is a lightweight version of Windows that can run entirely from memory
116 and can be used to install Windows from local media or a network drive or
117 perform maintenance. It is the operating system that runs when you boot from
118 the Windows installation media.
120 You can find Windows PE on the installation DVD for Windows Vista, Windows 7, or
121 Windows 8, in the file `sources/boot.wim'. Windows PE can also be found in the
122 Windows Automated Installation Kit (WAIK), which is free to download from
123 Microsoft, inside the `WinPE.cab' file, which you can extract natively on
124 Windows, or on UNIX if you install either the `cabextract' or `p7zip' programs.
126 In addition, Windows installations and recovery partitions frequently contain a
127 WIM containing an image of the Windows Recovery Environment, which is similar to
130 A shell script `mkwinpeimg' is distributed with wimlib on UNIX to ease the
131 process of creating and customizing a bootable Windows PE image.
135 This section documents the dependencies of wimlib and the programs distributed
136 with it, when building for UNIX from source. If you have downloaded the Windows
137 binary distribution of wimlib and wimlib-imagex then all dependencies were
138 already included and this section is irrelevant.
141 This is a commonly used free library to read and write XML files. You
142 likely already have it installed as a dependency for some other program.
143 For more information see http://xmlsoft.org/.
145 * libfuse (optional but highly recommended)
146 Unless configured with --without-fuse, wimlib requires a non-ancient
147 version of libfuse to be installed. Most Linux distributions already
148 include this, but make sure you have the libfuse package installed, and
149 also libfuse-dev if your distribution distributes header files
150 separately. FUSE also requires a kernel module. If the kernel module
151 is available it will automatically be loaded if you try to mount a WIM
152 file. For more information see http://fuse.sourceforge.net/. FUSE is
153 also available for FreeBSD.
155 * libntfs-3g (optional but highly recommended)
156 Unless configured with --without-ntfs-3g, wimlib requires the library
157 and headers for libntfs-3g version 2011-4-12 or later to be installed.
158 Versions dated 2010-3-6 and earlier do not work because they are missing
159 the header xattrs.h (and the file xattrs.c, which contains functions we
160 need). libntfs-3g version 2013-1-13 is compatible only with wimlib
163 * OpenSSL / libcrypto (optional)
164 wimlib can use the SHA1 message digest code from OpenSSL instead of
165 compiling in yet another SHA1 implementation. (See LICENSE section.)
169 * syslinux (optional)
170 * cabextract (optional)
171 The `mkwinpeimg' shell script will look for several other programs
172 depending on what options are given to it. Depending on your Linux
173 distribution, you may already have these programs installed, or they may
174 be in the software repository. Making an ISO filesystem requires
175 `mkisofs' from `cdrkit' (http://www.cdrkit.org). Making a disk image
176 requires `mtools' (http://www.gnu.org/software/mtools) and `syslinux'
177 (http://www.syslinux.org). Retrieving files from the Windows Automated
178 Installation Kit requires `cabextract' (http://www.cabextract.org.uk).
182 This section documents the most important options that may be passed to the
183 "configure" script when building the UNIX version from source:
186 If libntfs-3g is not available or is not version 2011-4-12 or later,
187 wimlib can be built without it, in which case it will not be possible to
188 apply or capture images directly to/from NTFS volumes.
191 If libfuse or the FUSE kernel module is not available, wimlib can be
192 compiled with --without-fuse. This will remove the ability to mount and
196 Build in functions for SHA1 rather than using external SHA1 functions
197 from libcrypto (part of OpenSSL). The default is to use libcrypto if it
198 is found on the system.
200 --enable-xattr, --disable-xattr
201 Enable or disable support for the extended-attributes interface to NTFS
202 alternate data streams in mounted WIMs. To support these, wimlib
203 requires that the setxattr() function and the attr/xattr.h header are
204 available. The default is to autodetect whether support is possible.
206 --disable-multithreaded-compression
207 By default, data will be compressed using multiple threads when writing
208 a WIM, unless only 1 processor is detected. Specify this option to
209 disable support for this.
212 Use a very fast assembly language implementation of SHA1 from Intel.
213 Only use this if the build target supports the SSSE3 instructions.
215 --disable-error-messages
216 Save some space by removing all error messages from the library.
219 Remove assertions included by default.
223 wimlib has primarily been tested on Linux and Windows (primarily Windows 7, but
224 also Windows XP and Windows 8).
226 wimlib may work on FreeBSD and Mac OS X. However, this is not well tested. If
227 you do not have libntfs-3g 2011-4-12 or later available, you must configure
228 wimlib with --without-ntfs-3g. On FreeBSD, before mounting a WIM you need to
229 load the POSIX message queue module (run `kldload mqueuefs').
231 wimlib has not been tested on big-endian CPU architectures.
235 The WIM file format is specified in a document that can be found in the
236 Microsoft Download Center. There is a similar document that specifies the LZX
237 compression format, and a document that specifies the XPRESS compression format.
238 However, many parts of these formats are poorly documented, and some parts have
239 no documentation whatsoever. Some particularly poorly documented parts of the
240 formats have had comments added in various places in the library code. Please
241 see the code and/or ask me if you have any questions about the WIM file format
242 as it exists in reality and not as it exists in Microsoft's poorly written
245 The code in ntfs-apply.c and ntfs-capture.c uses the NTFS-3g library, which is a
246 library for reading and writing to NTFS filesystems (the filesystem used by
247 recent versions of Windows). See
248 http://www.tuxera.com/community/ntfs-3g-download/ for more information.
250 lzx-decompress.c, the code to decompress WIM file resources that are compressed
251 using LZX compression, was originally based on code from the cabextract project
252 (http://www.cabextract.org.uk) but has been rewritten.
254 lzx-compress.c, the code to compress WIM file resources using LZX compression,
255 was originally based on code written by Matthew Russotto (www.russotto.net/chm/)
256 but has been rewritten.
258 lz77.c, the code to find LZ77 matches (used for both XPRESS and LZX
259 compression), is based on code from zlib but has been rewritten.
261 A limited number of other free programs can handle some parts of the WIM
264 * 7-zip is able to extract and create WIMs (as well as files in many
265 other archive formats). However, wimlib is designed specifically to handle
266 WIM files and provides features previously only available in Microsoft's
267 imagex.exe, such as the ability to mount WIMs read-write as well as
268 read-only, the ability to create LZX or XPRESS compressed WIMs, and the
269 correct handling of security descriptors and hard links.
270 * ImagePyX (https://github.com/maxpat78/ImagePyX) is a Python program that
271 provides similar capabilities to wimlib-imagex. One thing to note, though,
272 is that it does not support compression and decompression by itself, but
273 instead relies on external native code, such as the codecs from wimlib.
275 A very early version of wimlib is being used to deploy Windows 7 from the
276 Ultimate Deployment Appliance. For more information see
277 http://www.ultimatedeployment.org/.
279 You can see the documentation about Microsoft's version of ImageX at
280 http://technet.microsoft.com/en-us/library/cc749447(v=ws.10).aspx, so you can
281 see how it compares to wimlib-imagex.
283 If you are looking for a UNIX archive format that provides features similar to
284 WIM, I recommend you take a look at SquashFS (http://squashfs.sourceforge.net/).
288 As of version 1.0.0, wimlib and all programs and scripts distributed with it are
289 released under the GNU GPL version 3.0 or later.
291 wimlib is independently developed and does not contain any code, data, or files
292 copyrighted by Microsoft. It is not known to be affected by any patents.
294 On UNIX, if you do not want wimlib to be dynamically linked with libcrypto
295 (OpenSSL), configure with --without-libcrypto. This replaces the SHA1
296 implementation with built-in code and there will be no difference in
301 wimlib comes with no warranty whatsoever. Use Microsoft's `imagex.exe' if you
302 want to make sure your WIM files are made "correctly" (but beware: Microsoft's
303 version contains some bugs).
305 Please submit a bug report (to ebiggers3@gmail.com) if you find a bug in wimlib
306 and/or wimlib-imagex.
308 Be aware that some parts of the WIM file format are poorly documented or even
309 completely undocumented, so I've just had to do the best I can to read and write
310 WIMs that appear to be compatible with Microsoft's software.
git://wimlib.net / wimlib / blob