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).
Regulating access to the hardware is a fundamental kernel task. The Direct Rendering Manager and KMS are part of the Linux kernel. The KMS does only the mode setting.
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.
Microsoft Windows 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.
Linuxedit
The role of KMS (Kernel mode-setting), Linux example
The Linux kernel got the prerequisite for kernel-based mode setting by accepting Intel GEM in version 2.6.28, released in December 2008.[1] This will be[needs update] replaced by Tungstens Graphics TTM (Translation Table Maps) memory manager which supports the GEM API.[2] 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).[3] Support for Intel GMA graphic chipsets was accepted in version 2.6.29, released on March 23, 2009.[4] Support for pre-R600 ATI Radeon graphics cards was accepted in version 2.6.31, released on September 9, 2009.[5] Support for R600 and R700 was in development within DRM and was merged in version 2.6.32.[6] 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 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.[7]Wayland compositors (e.g. Weston) and kmscon depend on kernel mode setting via ioctl.
FreeBSDedit
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.[8]
NetBSDedit
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.[9]
OpenBSDedit
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.
Alternativesedit
This section needs to be updated. Please help update this article to reflect recent events or newly available information.(August 2014)
The following alternatives have been presented during the Linux Plumbers Conference 2013:
^"Announcing NetBSD 7.0". The NetBSD Project. 25 September 2015. Retrieved 25 April 2016.
^. www.linuxplumbersconf.org. Archived from the original on 2013-10-30.
^"Atomic Display Framework / Linux Plumbers Conference: Developing the Kernel, Libraries and Utilities".
^. Archived from the original on 2015-08-31. Retrieved 2013-08-29.
^. www.linuxplumbersconf.org. Archived from the original on 2016-03-12.
External linksedit
Mode Setting on the X.org wiki
Intel Graphics Driver on the X.org wiki
ATI Radeon driver on the X.org wiki
Kernel Mode Setting on the Fedora project wiki
April 12, 2024
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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 Regulating access to the hardware is a fundamental kernel task The Direct Rendering Manager and KMS are part of the Linux kernel The KMS does only the mode setting 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 Contents 1 Implementation 1 1 Microsoft Windows 1 2 Linux 1 3 FreeBSD 1 4 NetBSD 1 5 OpenBSD 2 Alternatives 3 See also 4 References 5 External linksImplementation editMicrosoft Windows edit Microsoft Windows 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 edit The role of KMS Kernel mode setting Linux example nbsp Wayland compositors require KMS and also OpenGL ES and EGL nbsp evdev is the Linux kernel module that receives data from various Input devices such as Keyboard Mouse Touch Pad etc The data is passed to the Display server e g the X Org Server or some Wayland compositor only to be passed further to the Wayland client respectively X client Some applications require a minimal latency Main article Direct Rendering Manager The Linux kernel got the prerequisite for kernel based mode setting by accepting Intel GEM in version 2 6 28 released in December 2008 1 This will be needs update replaced by Tungstens Graphics TTM Translation Table Maps memory manager which supports the GEM API 2 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 3 Support for Intel GMA graphic chipsets was accepted in version 2 6 29 released on March 23 2009 4 Support for pre R600 ATI Radeon graphics cards was accepted in version 2 6 31 released on September 9 2009 5 Support for R600 and R700 was in development within DRM and was merged in version 2 6 32 6 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 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 7 Wayland compositors e g Weston and kmscon depend on kernel mode setting via ioctl FreeBSD edit 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 8 NetBSD edit 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 9 OpenBSD edit 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 editThis section needs to be updated Please help update this article to reflect recent events or newly available information August 2014 The following alternatives have been presented during the Linux Plumbers Conference 2013 It was suggested to split GEM and KMS 10 Atomic Display Framework by Google s Android Team 11 12 Common Display Framework 13 See also editScreens of deathReferences edit Linux 2 6 28 Linux Kernel Newbies Retrieved 2013 02 14 Larabel Michael 2008 08 26 A GEM ified TTM Manager For Radeon Phoronix Retrieved 2013 02 14 Larabel Michael 2009 06 10 TTM Memory Manager Gets Ready For Release Phoronix Retrieved 2013 02 14 Linux 2 6 29 Linux Kernel Newbies Retrieved 2013 02 14 Linux 2 6 31 Linux Kernel Newbies 2009 09 09 Retrieved 2013 02 14 Larabel Michael 2009 09 30 AMD R600 700 2D Performance Open vs Closed Drivers Phoronix Retrieved 2013 02 14 nouveau KernelModeSetting freedesktop org 24 August 2013 Retrieved 2014 08 11 FreeBSD 9 1 RELEASE Release Notes FreeBSD Foundation 30 December 2012 Announcing NetBSD 7 0 The NetBSD Project 25 September 2015 Retrieved 25 April 2016 Splitting DRM KMS device nodes Linux Plumbers Conference Developing the Kernel Libraries and Utilities www linuxplumbersconf org Archived from the original on 2013 10 30 Atomic Display Framework Linux Plumbers Conference Developing the Kernel Libraries and Utilities KMS HWComposer issues the Atomic Display Framework and other KMS Extentions Linux Plumbers Conference Developing the Kernel Libraries and Utilities Archived from the original on 2015 08 31 Retrieved 2013 08 29 Common Display Framework Linux Plumbers Conference Developing the Kernel Libraries and Utilities www linuxplumbersconf org Archived from the original on 2016 03 12 External links editMode Setting on the X org wiki Intel Graphics Driver on the X org wiki ATI Radeon driver on the X org wiki Kernel Mode Setting on the Fedora project wiki Retrieved from https en wikipedia org w index php title Mode setting amp oldid 1191088448, wikipedia, wiki, book, books, library,
