Mode setting is a software operation that activates a display mode (screen resolution, color depth, and refresh rate) for a computer's display controller by using VESA BIOS Extensions or UEFI Graphics extensions (on more modern computers). The display mode is set by the kernel. In ''user-space mode-setting'' (UMS), the display mode is set by a user-space process. Kernel mode-setting is more flexible and allows displaying of an error in the case of a fatal system error in the kernel, even when using a user-space display server. User-space mode setting would require superuser privileges for direct hardware access, so kernel-based mode setting shuns such requirement for the user-space graphics server.

Implementation

For "old" cards, support might change from distribution to distribution according to random criteria without apparent reason leaving the card unsupported.

Microsoft Windows

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

versions that are NT-based use kernel mode setting. The kernel error display made possible by kernel mode setting is officially called "bug check", but more commonly known as the Blue Screen of Death.

Linux

The

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

got the prerequisite for kernel-based mode setting by accepting Intel GEM in version 2.6.28, released in December 2008. This will be replaced by Tungstens Graphics TTM (Translation Table Maps) memory manager which supports the GEM API. TTM was developed for the free and open-source drivers for Radeon and S3 Graphics graphic chipsets (''see Free and open-source graphics device driver''). Support for

Intel GMA The Intel Graphics Media Accelerator (GMA) is a series of integrated graphics processors introduced in 2004 by Intel, replacing the earlier Intel Extreme Graphics series and being succeeded by the Intel HD and Iris Graphics series. This serie ...

graphic chipsets was accepted in version 2.6.29, released on March 23, 2009. Support for pre-R600 ATI Radeon graphics cards was accepted in version 2.6.31, released on September 9, 2009. Support for R600 and R700 was in development within DRM and was merged in version 2.6.32. Support for Evergreen (R800) was merged in version 2.6.34. As Nvidia did not release all the needed documentation for its graphics chip, development proceeded under the nouveau project, which uses

reverse engineering Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompl ...

to build a working open-source driver for Nvidia cards. Nouveau was accepted in version 2.6.33 of the kernel, released on December 10, 2009. Kernel-based mode setting is not only supported by the nouveau driver, it is required. Wayland compositors (e.g.

Weston Weston may refer to: Places Australia * Weston, Australian Capital Territory, a suburb of Canberra * Weston, New South Wales * Weston Creek, a residential district of Canberra * Weston Park, Canberra, a park Canada * Weston, Nova Scotia * W ...

) and kmscon depend on kernel mode setting via ioctl.

FreeBSD

FreeBSD has support for both kernel-based mode setting and GEM for later generations of Intel GPUs (IronLake, SandyBridge, and IvyBridge) starting with version 9.1. Support of Intel card is limited. Some random Intel cards such as Device 'Intel CometLake-S GT2 HD Graphics 630 does not work with FreeBSD. Some cards where driver is supported but not supported actively and does not work suffer such kind of issues.

NetBSD

NetBSD has support for kernel-based mode setting and accelerated graphics for Intel and Radeon devices. This implementation was introduced in version 7.0 by porting the Linux 3.15 DRM/KMS code.

OpenBSD

OpenBSD has kernel-based mode setting support for Intel and Radeon GPUs. Starting with version 5.4 of OpenBSD, support for Intel GPUs is available. With the release of version 5.5, the implementation has been extended to add support for Radeon chipsets as well.

Alternatives

The following alternatives have been presented during the Linux Plumbers Conference 2013: * It was suggested to split GEM and KMS. * Atomic Display Framework, by Google's Android-Team. * Common Display Framework.

References

{{Reflist, refs= {{ cite web , url = http://kernelnewbies.org/Linux_2_6_28#head-b957b19f6139b6bbbfabaf790bf643b1746985d6 , title = Linux 2 6 28 , publisher = Linux Kernel Newbies , date = , accessdate = 2013-02-14 {{ cite web , url = https://www.phoronix.com/scan.php?page=news_item&px=NjY3Ng , title = A GEM-ified TTM Manager For Radeon , first = Michael , last = Larabel , publisher = Phoronix , date = 2008-08-26 , accessdate = 2013-02-14 {{ cite web , url = https://www.phoronix.com/scan.php?page=news_item&px=NzMxOA , title = TTM Memory Manager Gets Ready For Release , first = Michael , last = Larabel , publisher = Phoronix , date = 2009-06-10 , accessdate = 2013-02-14 {{ cite web , url = http://kernelnewbies.org/Linux_2_6_29#head-e1bab8dc862e3b477cc38d87e8ddc779a66509d1 , title = Linux 2 6 29 , publisher = Linux Kernel Newbies , date = , accessdate = 2013-02-14 {{ cite web , url = http://kernelnewbies.org/Linux_2_6_31#head-78158343fc06e5e289f2ccaf51d6a30090a46524 , title = Linux 2 6 31 , publisher = Linux Kernel Newbies , date = 2009-09-09 , accessdate = 2013-02-14 {{ cite web , url = https://www.phoronix.com/scan.php?page=article&item=amd_r600_r700_2d , title = AMD R600/700 2D Performance: Open vs. Closed Drivers , first = Michael , last = Larabel , publisher = Phoronix , date = 2009-09-30 , accessdate = 2013-02-14 {{ cite web , title = FreeBSD 9.1-RELEASE Release Notes , url= http://www.freebsd.org/releases/9.1R/relnotes.html , date = 30 December 2012 , publisher = FreeBSD Foundation {{ cite web , title = Announcing NetBSD 7.0 , url = https://netbsd.org/releases/formal-7/NetBSD-7.0.html , date = 25 September 2015 , publisher = The NetBSD Project , accessdate = 25 April 2016 {{ cite web , url=http://nouveau.freedesktop.org/wiki/KernelModeSetting/ , title=nouveau/ KernelModeSetting , publisher=freedesktop.org , date=24 August 2013 , accessdate=2014-08-11