- WIMLIB
-
-This is wimlib version 1.2.4 (January 2013). 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.
-
-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
+ INTRODUCTION
+
+This is wimlib version 1.7.4 (January 2015). wimlib is a C library for
+creating, modifying, extracting, and mounting files in the Windows Imaging
+Format (WIM files). wimlib and its command-line frontend 'wimlib-imagex'
+provide a free and cross-platform alternative to Microsoft's WIMGAPI, ImageX,
+and DISM.
+
+ INSTALLATION
+
+To install wimlib and wimlib-imagex on Windows, simply download and extract the
+ZIP file containing the latest binaries from the SourceForge page
+(http://sourceforge.net/projects/wimlib/). You probably have already done this!
+
+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 multiple compression formats,
+including LZX, XPRESS, and LZMS. All these formats 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.
+
+Since version 1.6.0, wimlib also supports ESD (.esd) files, except when
+encrypted. These are still WIM files but they use a newer version of the file
+format.
+
+ 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, LZX, or LZMS compressed WIM files.
+wimlib includes its own compression codecs and does not use the compression API
+available on some versions of Windows.
+
+I have gradually been improving the compression codecs in wimlib. For XPRESS
+and LZX, they now usually outperform and outcompress the equivalent Microsoft
+implementations. Although results will vary depending on the data being
+compressed, in the table below I present the results for a common use case:
+compressing an x86 Windows PE image. Each row displays the compression type,
+the size of the resulting WIM file in bytes, and how many seconds it took to
+create the file. When applicable, the results with the equivalent Microsoft
+implementation in WIMGAPI is included.
+
+ =============================================================================
+ | Compression || wimlib (v1.7.4) | WIMGAPI (Windows 8.1) |
+ =============================================================================
+ | None [1] || 361,314,224 in 2.4s | 361,315,338 in 4.5s |
+ | XPRESS [2] || 138,218,750 in 3.0s | 140,457,436 in 6.0s |
+ | XPRESS (slow) [3] || 135,173,511 in 8.9s | N/A |
+ | LZX (quick) [4] || 130,332,007 in 4.1s | N/A |
+ | LZX (normal) [5] || 126,714,807 in 12.5s | 127,293,240 in 19.2s |
+ | LZX (slow) [6] || 126,150,743 in 20.5s | N/A |
+ | LZMS (non-solid) [7] || 121,909,792 in 11.9s | N/A |
+ | LZMS (solid) [8] || 93,650,936 in 45.0s | 88,771,192 in 109.2 |
+ | "WIMBoot" [9] || 167,023,719 in 3.5s | 169,109,211 in 10.4s |
+ | "WIMBoot" (slow) [10] || 165,027,583 in 7.9s | N/A |
+ =============================================================================
+
+Notes:
+ [1] '--compress=none' for wimlib-imagex; '/compress:none' for DISM.
+
+ [2] '--compress=XPRESS' for wimlib-imagex; '/compress:fast' for DISM.
+ Compression chunk size defaults to 32768 bytes in both cases.
+
+ [3] '--compress=XPRESS:80' for wimlib-imagex; no known equivalent for DISM.
+ Compression chunk size defaults to 32768 bytes.
+
+ [4] '--compress=LZX:20' for wimlib-imagex; no known equivalent for DISM.
+ Compression chunk size defaults to 32768 bytes.
+
+ [5] '--compress=LZX' or '--compress=LZX:50' or no option for wimlib-imagex;
+ '/compress:maximum' for DISM.
+ Compression chunk size defaults to 32768 bytes in both cases.
+
+ [6] '--compress=LZX:100' for wimlib-imagex; no known equivalent for DISM.
+ Compression chunk size defaults to 32768 bytes.
+
+ [7] '--compress=LZMS' for wimlib-imagex; no known equivalent for DISM.
+ Compression chunk size defaults to 131072 bytes.
+
+ [8] '--solid' for wimlib-imagex. Should be '/compress:recovery' for DISM,
+ but only works for /Export-Image, not /Capture-Image. Compression chunk
+ size in solid blocks defaults to 33554432 for wimlib, 67108864 for DISM.
+
+ [9] '--wimboot' for wimlib-imagex; '/wimboot' for DISM.
+ This is really XPRESS compression with 4096 byte chunks, so the same as
+ '--compress=XPRESS --chunk-size=4096'.
+
+ [10] '--wimboot --compress=XPRESS:80' for wimlib-imagex;
+ no known equivalent for DISM.
+ Same format as [9], but trying harder to get a good compression ratio.
+
+Note: wimlib-imagex's --compress option also accepts the "fast", "maximum", and
+"recovery" aliases for XPRESS, LZX, and LZMS, respectively.
+
+Testing environment:
+
+ - 64 bit binaries
+ - Windows 8.1 virtual machine running on Linux with VT-x
+ - 4 CPUs and 4 GiB memory given to virtual machine
+ - SSD-backed virtual disk
+ - All tests done with page cache warmed
+
+The compression ratio provided by wimlib is also competitive with commonly used
+archive formats. Below are file sizes that result when the Canterbury corpus is
+compressed with wimlib (v1.7.2), WIMGAPI (Windows 8.1), and some other
+formats/programs:
+
+ =====================================================
+ | Format | Size (bytes) |
+ =====================================================
+ | tar | 2,826,240 |
+ | WIM (WIMGAPI, None) | 2,814,254 |
+ | WIM (wimlib, None) | 2,814,216 |
+ | WIM (WIMGAPI, XPRESS) | 825,536 |
+ | WIM (wimlib, XPRESS) | 790,016 |
+ | tar.gz (gzip, default) | 738,796 |
+ | ZIP (Info-ZIP, default) | 735,334 |
+ | tar.gz (gzip, -9) | 733,971 |
+ | ZIP (Info-ZIP, -9) | 732,297 |
+ | WIM (wimlib, LZX quick) | 704,006 |
+ | WIM (WIMGAPI, LZX) | 651,866 |
+ | WIM (wimlib, LZX normal) | 632,614 |
+ | WIM (wimlib, LZX slow) | 625,050 |
+ | WIM (wimlib, LZMS non-solid) | 581,960 |
+ | tar.bz2 (bzip, default) | 565,008 |
+ | tar.bz2 (bzip, -9) | 565,008 |
+ | WIM (wimlib, LZX solid) | 532,700 |
+ | WIM (wimlib, LZMS solid) | 525,990 |
+ | WIM (wimlib, LZX solid, slow) | 525,140 |
+ | WIM (wimlib, LZMS solid, slow) | 523,728 |
+ | WIM (WIMGAPI, LZMS solid) | 521,366 |
+ | WIM (wimlib, LZX solid, very slow) | 520,832 |
+ | tar.xz (xz, default) | 486,916 |
+ | tar.xz (xz, -9) | 486,904 |
+ | 7z (7-zip, default) | 484,700 |
+ | 7z (7-zip, -9) | 483,239 |
+ =====================================================
+
+Note: WIM does even better on directory trees containing duplicate files, which
+the Canterbury corpus doesn't have.
+
+ 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 an 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