Release Notes for X11R7.5

Introduction to the X11R7.5 Release

This release is the sixth modular release of the X Window System. The next full release will be X11R7.6 and is expected in 2010.

Unlike X11R1 through X11R6.9, X11R7.x releases are not built from one monolithic source tree, but many individual modules. These modules are distributed as individual source code releases, and each one is released when it is ready, instead of only when the overall window system is ready for release. The X11R7.x releases are made by “rolling up” the individual module releases into a collection that is often affectionately called the “katamari” by the developers.

The X11R7.5 release does not include all of the software formerly included in the previous X Window System releases. It is designed to be a reasonable baseline from which to start when building the window system for the first time for a new installation, distribution, or package set. It does not provide a full desktop environment, expecting a more feature rich set of applications to be installed from one of the several excellent desktop environments available for the X Window System. The X.Org developers continue to maintain and produce new releases of much of the software that was formerly in the main window system releases but is no longer included in the katamari releases, including many of the Athena Widgets desktop applications that were provided as samples in previous window system versions.

Once their window system build is established, most builders watch for announcements of individual module updates on the xorg-announce mailing list and update to those as needed. The X.Org Foundation currently releases the X Window System katamari releases approximately once a year, but many modules, especially the X servers and drivers, are updated more frequently between those releases.

For help with how to build and develop in the modular tree see the Modular Developer's Guide in the X.Org wiki.

We encourage you to submit bug fixes and enhancements to freedesktop.org's bug tracking system using the xorg product, and to discuss them on <xorg@lists.freedesktop.org>. More details on patch submission and review process are available on the SubmittingPatches page of the X.Org wiki.

The release numbering is based on the original MIT X numbering system. X11 refers to the version of the network protocol that the X Window system is based on: Version 11 was first released in 1988 and has been stable for 21 years, with only upward compatible additions to the core X protocol, a record of stability envied in computing. Formal releases of X started with X version 9 from MIT; the first commercial X products were based on X version 10. The MIT X Consortium and its successors, the X Consortium, the Open Group X Project Team, and the X.Org Group released versions X11R3 through X11R6.6. Since the founding of the X.Org Foundation in early 2004, many further releases have been issued, from X11R6.7 to the current 7.5.

The next section describes what is new in the latest version (7.5) compared with the previous full release (7.4).

Summary of new features in X11R7.5

This is a sampling of the new features in X11R7.5. A more complete list of changes can be found in the ChangeLog files that are part of the source of each X module.

• Multi-Pointer X (MPX) provides the user with multiple independent mouse cursors and multiple independent keyboard foci. Each cursor is a true system cursor and different pointers can operate in multiple applications simultaneously.

• Input device properties allow you to attach properties to a device. These properties can be of arbitrary type and can be changed without the server having to know their details.

• The X Input Extension version 2.0 (XI2) is designed to replace both core input processing and prior versions of the X Input Extension. Besides MPX, it provides a number of other enhancements over version 1.5, including:

  • use of XGE and GenericEvents.

  • explicit device hierarchy of master and slave devices.

  • the ability for devices to change capabilities at runtime.

  • raw device events

• Resize, Rotate and Reflect Extension (RANDR) version 1.3 builds on the changes made with version 1.2 and adds some new capabilities without fundmentally changing the extension again. The following features are added in this version:

  Projective Transforms

  The implementation work for general rotation support made it trivial to add full projective transformations. These can be used to scale the screen up/down as well as perform projector keystone correct or other effects.

  Panning

  Panning was removed with RandR 1.2 because the old semantics didn't fit any longer. With RandR 1.3 panning can be specified per crtc.

• The DRI2 extension is designed to associate and access auxillary rendering buffers with an X drawable. It is a essentially a helper extension to support implementation of direct rendering drivers/libraries/technologies. The first consumer of this extension is a direct rendering OpenGL driver, but the DRI2 extension is not designed to be OpenGL specific. Work is underway to utilize DRI2 for the Video Decode and Presentation API for Unix (VPDAU) as well. Direct rendering implementations of OpenVG, Xv, cairo and other graphics APIs should find the functionality exposed by this extension helpful and hopefully sufficient.

• Video and input driver enhancements. Please see the ChangeLog files for individual drivers; there are far too many updates to list here.

• ... and the usual assortment of correctness and crash fixes.

Overview of X11R7.5

On most platforms, X11R7.5 has a single hardware-driving X server binary called Xorg. This binary can dynamically load the video drivers, input drivers, and other modules that are needed. Xorg has currently has support for Linux, Solaris, and some BSD OSs on Alpha, PowerPC, IA-64, AMD64, Intel x86, Sparc, and MIPS platforms.

Additional specialized X server binaries may be found depending on the platform and build configuration, including:

Details of X11R7.5 components

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Xorg server

Loader and Modules

The Xorg server relies on the operating system's native module loader support for handling program modules. The X server makes use of modules for video drivers, X server extensions, input device drivers, framebuffer layers, and internal components used by some drivers (like XAA & EXA).

The module interfaces (both API and ABI) used in this release are subject to change without notice. While we will attempt to provide backward compatibility for the module interfaces, we cannot guarantee this. Compatibility in the other direction is explicitly not guaranteed because new modules may rely on interfaces added in new releases.

Note about module security

The X server runs with root privileges, i.e., the X server loadable modules also run with these privileges. For this reason we recommend that all users be careful to only use loadable modules from reliable sources, otherwise the introduction of viruses and contaminated code can occur and wreak havoc on your system. We hope to have a mechanism for signing/verifying the modules that we provide available in a future release.

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Configuration File

The Xorg server uses a configuration file as the primary mechanism for providing configuration and run-time parameters. The configuration file format is described in detail in the xorg.conf(5) manual page.

Note that this release features significant improvements for running the server without a configuration file, so many users may find that that they don't need a configuration file.

If you do need to customize the configuration file, see the xorg.conf manual page . You can also check the driver-specific manual pages and the related documentation (found at driver tables) also.

The recommended method for generating a configuration file is to use the Xorg server itself. Run as root:

Xorg -configure

and follow the instructions.

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Command Line Options

Command line options can be used to override some default parameters and parameters provided in the configuration file. These command line options are described in the Xorg(1) manual page.

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XAA

The XFree86 Acceleration Architecture (XAA) was completely rewritten from scratch for XFree86 4.x and is used in X11R7.5. Most drivers implement acceleration by making use of the XAA module.

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EXA

EXA was created as a new driver acceleration architecture to replace XAA. EXA was designed specifically to accelerate Render operations. This release features improved driver support for EXA. See the individual driver changelogs for details.

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Multi-head

Some multi-head configurations are supported in X11R7.5. Support for multiple PCI/AGP cards may require a kernel with changes to support VGA arbitration.

One of the main problems is with drivers not sufficiently initializing cards that were not initialized at boot time. This has been improved somewhat with the INT10 support that is used by most drivers (which allows secondary card to be "soft-booted", but in some cases there are other issues that still need to be resolved. Some combinations can be made to work better by changing which card is the primary card (either by using a different PCI slot, or by changing the system BIOS's preference for the primary card).

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Xinerama

Xinerama is an X server extension that allows multiple physical screens to behave as a single screen. With traditional multi-head in X11, windows cannot span or cross physical screens. Xinerama removes this limitation. Xinerama does, however, require that the physical screens all have the same root depth, so it isn't possible, for example, to use an 8-bit screen together with a 16-bit screen in Xinerama mode.

Xinerama is not enabled by default, and can be enabled with the +xinerama command line option for the X server.

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DDC

The VESA® Display Data Channel (DDC^TM) standard allows the monitor to tell the video card (or in some cases the computer directly) about itself; particularly the supported screen resolutions and refresh rates.

Partial or complete DDC support is available in most of the video drivers. DDC is enabled by default, but can be disabled with a "Device" section entry: Option "NoDDC". We have support for DDC versions 1 and 2; these can be disabled independently with Option "NoDDC1" and Option "NoDDC2".

At startup the server prints out DDC information from the display, and can use this information to set the default monitor parameters, or to warn about monitor sync limits if those provided in the configuration file don't match those that are detected.

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Changed behavior caused by DDC.

Several drivers use DDC information to set the screen size and pitch. This can be overridden by explicitly resetting it to the and non-DDC default value 75 with the -dpi 75 command line option for the X server, or by specifying appropriate screen dimensions with the "DisplaySize" keyword in the "Monitor" section of the config file.

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GLX and the Direct Rendering Infrastructure (DRI)

Direct rendered OpenGL® support is provided for several hardware platforms by the Direct Rendering Infrastructure (DRI). Further information about DRI can be found at the DRI Project's web site. The 3D core rendering component is provided by Mesa.

Of note is that this release supports building the X server using the system-wide libdrm. Previously, drm was kept in the server's tree and loaded as a module, rather than using the standard OS mechanisms for managing shared libraries of code. This requires that the server be built using a version of libdrm of 2.3.0 or newer if it is to use DRM.

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Terminate Server keystroke

The Xorg server has previously allowed users to exit the server by pressing the keys Control + Alt + Backspace. While this function is still enabled by default in this release, the keymap data usually used with Xorg, from the xkeyboard-config project, has been modified to not map that sequence by default, in order to reduce the chance that inexperienced users will accidentally destroy their work.

Users who wish to have this functionality available by default may enable it via the XKB configuration option “terminate:ctrl_alt_bksp”. For instance, the setxkbmap command can be used to enable this by running:

setxkbmap -option "terminate:ctrl_alt_bksp"

Many desktop environments include XKB configuration options in their preferences to enable this as well.

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X Server startup state

The X servers in the X11R7.5 release now start by default with an empty black screen and do not draw the mouse cursor until a client sets the cursor image. To restore the classic behavior of starting with the grey weave pattern and × cursor, start the X server with the -retro option.

Build changes and issues

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Miscellaneous

This section describes other items of note for the X11R7.5 release.

        /tmp/.font-unix
        /tmp/.ICE-unix
        /tmp/.X11-unix
        

Deprecated components and removal plans

This section lists current plans for removal of obsolete or deprecated components in the X.Org releases. As our releases are open source, users who continue to require these can find the source in previous releases and continue to use these, but the X.Org Foundation and its volunteers have decided the burden of continued maintenance and distribution in the core X11 releases outweighs the benefits of doing so. In some cases, this is simply because no one has volunteered to do continued maintenance, so if software is listed here that you need, you can contact <xorg@lists.freedesktop.org> to volunteer to take over maintainership, either inside or outside of the Xorg release process.

Attributions/Acknowledgements/Credits

This section lists the credits for the X11R7.5 release. For a more detailed breakdown, refer to the ChangeLog file in the source tree for each module, the history in the xorg product in freedesktop.org's git repositories or the 'git log' information for individual source files.

The X Window System has been a collaborative effort from its inception. Our apologies for anyone or organization inadvertently overlooked. Many individuals (including major contributors) who worked on X are represented by their employers in this list. If you feel we have left anyone out, please let us know.

These people contributed in some way to X11R7.5:

This product includes software developed by:

This product includes software developed by The XFree86 Project, Inc (http://www.xfree86.org/) and its contributors.

This product includes software that is based in part of the work of the FreeType Team (http://www.freetype.org/).

This product includes software developed by the University of California, Berkeley and its contributors.

This product includes software developed by Christopher G. Demetriou.

This product includes software developed by the NetBSD Foundation, Inc. (http://www.netbsd.org/) and its contributors.

This product includes software developed by X-Oz Technologies (http://www.x-oz.com/).